Carbazole is an irreplaceable basic organic chemical raw material and intermediate in industry.The separation of carbazole from anthracene oil by environmental benign solvents is important but still a challenge in che...Carbazole is an irreplaceable basic organic chemical raw material and intermediate in industry.The separation of carbazole from anthracene oil by environmental benign solvents is important but still a challenge in chemical engineering.Deep eutectic solvents (DESs) as a sustainable green separation solvent have been proposed for the separation of carbazole from model anthracene oil.In this research,three quaternary ammonium-based DESs were prepared using ethylene glycol (EG) as hydrogen bond donor and tetrabutylammonium chloride (TBAC),tetrabutylammonium bromide or choline chloride as hydrogen bond acceptors.To explore their extraction performance of carbazole,the conductor-like screening model for real solvents (COSMO-RS) model was used to predict the activity coefficient at infinite dilution (γ^(∞)) of carbazole in DESs,and the result indicated TBAC:EG (1:2) had the stronger extraction ability for carbazole due to the higher capacity at infinite dilution (C^(∞)) value.Then,the separation performance of these three DESs was evaluated by experiments,and the experimental results were in good agreement with the COSMO-RS prediction results.The TBAC:EG (1:2) was determined as the most promising solvent.Additionally,the extraction conditions of TBAC:EG (1:2) were optimized,and the extraction efficiency,distribution coefficient and selectivity of carbazole could reach up to 85.74%,30.18 and 66.10%,respectively.Moreover,the TBAC:EG (1:2) could be recycled by using environmentally friendly water as antisolvent.In addition,the separation performance of TBAC:EG (1:2) was also evaluated by real crude anthracene,the carbazole was obtained with purity and yield of 85.32%,60.27%,respectively.Lastly,the extraction mechanism was elucidated byσ-profiles and interaction energy analysis.Theoretical calculation results showed that the main driving force for the extraction process was the hydrogen bonding ((N–H...Cl) and van der Waals interactions (C–H...O and C–H...π),which corresponding to the blue and green isosurfaces in IGMH analysis.This work presented a novel method for separating carbazole from crude anthracene oil,and will provide an important reference for the separation of other high value-added products from coal tar.展开更多
The development of green solvents for enhancing aqueous solubility of drug curcumin remains a challenge. This study explores the enhancing effect of deep eutectic solvents(DESs) on the aqueous solubility of curcumin(C...The development of green solvents for enhancing aqueous solubility of drug curcumin remains a challenge. This study explores the enhancing effect of deep eutectic solvents(DESs) on the aqueous solubility of curcumin(CUR) via experiment and theoretical calculation. Choline chloride-based DESs with polyols 1,2-propanediol(1,2-PDO), 1,3-propanediol, ethylene glycol, and glycerol as hydrogen bond donors were prepared and used as co-solvents. The CUR aqueous solubility increased with increasing the DESs content at temperature of 303.15-318.15 K, especially in aqueous ChCl/1,2-PDO(mole ratio 1:4) solutions. The positive apparent molar volume values and reduced density gradient analysis confirmed the existence of strong interactions between CUR and solvent. The van der Waals interactions and hydrogen bonding coexisted in DESs monomer retained the stability of DESs structure after introducing CUR. Moreover,the lower interaction energy of DESs…CUR system than that of the counterpart DESs further proved the strong interaction between CUR and DESs. The lowest interaction energy of ChCl/1,2-PDO…CUR system indicated that this system was the most stable and ChCl/1,2-PDO was promising for CUR dissolution.This work provides efficient solvents for utilizing curcumin, contributing to a deep insight into the interactions between DES and CUR at the molecular level, and the role of DESs on enhancing drugs solubility.展开更多
Important efforts have been made over the past years to improve the drug acts,which leads to the discovery of novel drug preparations and delivery systems.The optimal design of such processes requires a molecular-leve...Important efforts have been made over the past years to improve the drug acts,which leads to the discovery of novel drug preparations and delivery systems.The optimal design of such processes requires a molecular-level understanding of the interactions between drug molecules and biological membranes.The thermodynamic investigation provides deep and complete knowledge of interactions and the choice of appropriate and suitable production compounds in pharmaceutical fields.Particularly,the analysis of drugs+co-solvents in aqueous media is the central issue in many types of research because they exert their impact by interacting with biological membranes.This work is aimed to measure the density and speed of sound for the thiamine hydrochloride in water+deep eutectic solvents(DESs)mixtures(choline chloride/urea,choline chloride/ethylene glycol and choline chloride/glycerol)at temperature range(293.15-308.15)K.By correlation of the evaluated parameters in some standard relations,the partial molar parameters i.e.apparent molar volumes,Vφ,m,and apparent molar isentropic compression,κ_(s,φ,m),are calculated.In addition,apparent molar isobaric expansion,E^(0)_(φ,m),and Hepler’s constant are computed from the density and speed of sound data.For fitting the experimental Vφ,m andκ_(s,φ,m)the Redlich-Meyer equation was employed that the important quantities;standard partial molar volume,V^(0)_(m),and partial molar isentropic compression,κφ,m0,were obtained.The thermodynamic analysis of the studied system also plays a crucial role in the pharmaceutical industry.展开更多
Fracturing fluid property play a critical role in developing unconventional reservoirs.Deep eutectic solvents(DESs)show fascinating potential for property improvement of clean fracturing fluids(CFFs)due to their low-p...Fracturing fluid property play a critical role in developing unconventional reservoirs.Deep eutectic solvents(DESs)show fascinating potential for property improvement of clean fracturing fluids(CFFs)due to their low-price,low-toxicity,chemical stability and flexible designability.In this work,DESs were synthesized by mixing hydrogen bond acceptors(HBAs)and a given hydrogen bond donor(HBD)to explore their underlying influence on CFF properties based on the intermolecular interactions.The hydrogen-bonding,van der Waals and electrostatic interactions between DES components and surfactants improved the CFF properties by promoting the arrangement of surfactants at interface and enhancing the micelle network strength.The HBD enhanced the resistance of CFF for Ca^(2+) due to coordination-bonding interaction.The DESs composed of choline chloride(ChCl)and malonic acid show great enhancement for surface,rheology,temperature resistance,salt tolerance,drag reduction,and gel-breaking performance of CFFs.The DESs also improved the gel-breaking CFF-oil interactions,increasing the imbibition efficiencies to 44.2%in 74 h.Adjusting HBAs can effectively strengthen the intermolecular interactions(e.g.,HBA-surfactant and HBD-surfactant interactions)to improve CFF properties.The DESs developed in this study provide a novel strategy to intensify CFF properties.展开更多
Solvents are generally used to reduce the viscosity of heavy crude oil and ultimately enhance oil recovery.Recently,a new method has been introduced where nanoparticles(NPs)are exploited to induce enhanced oil recover...Solvents are generally used to reduce the viscosity of heavy crude oil and ultimately enhance oil recovery.Recently,a new method has been introduced where nanoparticles(NPs)are exploited to induce enhanced oil recovery owing to their ability to improve the mobility ratio,dampen the interfacial tension,and alter rock wett-ability.This study investigated the integration of nano-alumina(Al_(2)O_(3))NPs with an n-hexane solvent.In parti-cular,a Brookfield viscometer has been used to measure the crude oil viscosity and it has been found that NPs can effectively lead to a significant decrease in the overall oil viscosity(70 cp using the solvent only,45 cp when NPs are added).展开更多
Extraction of castor oil from castor seeds was investigated using different green solvents which include d-limonene, p-cymene, α-pinene, ethanol, and furfural at the temperature range of (323 - 413) K. The Soxhlet ex...Extraction of castor oil from castor seeds was investigated using different green solvents which include d-limonene, p-cymene, α-pinene, ethanol, and furfural at the temperature range of (323 - 413) K. The Soxhlet extraction method was employed to investigate the effect of temperature at atmospheric pressure. The focus of the study was to investigate a potential green solvent that can produce the high yields compared to the traditional solvent (hexane). The results show that at the average time of 3 hours and 30 minutes, the castor oil yield for green solvents were ranked as furfural (47.13%) > ethanol (45.37%) > p-cymene (39.15%) > d-limonene (39.13%) > α-pinene (38.11%). These castor oil yields were obtained at optimum temperatures for each green solvent. The castor oil yields were compared to the yield of hexane (31.36%) at same average time. The green solvents were recovered by using simple distillation, except furfural which was difficult to be recovered.展开更多
As the demand for sustainable energy sources continues to rise,the need for efficient and reliable energy storage systems becomes crucial.In order to effectively store and distribute renewable energy,new and innovativ...As the demand for sustainable energy sources continues to rise,the need for efficient and reliable energy storage systems becomes crucial.In order to effectively store and distribute renewable energy,new and innovative solutions must be explored.This review examines the deep eutectic solvents(DESs)as a green,safe,and affordable solution for the electrochemical energy storage and conversion field,offering tremendous opportunities and a promising future.DESs are a class of environment-friendly solvents known for their low toxicity and unique properties,such as their good conductivity,high thermal stability,and nonflammability.This review explores the fundamentals,preparations,and various interactions that often predominate in the formation of DESs,the properties of DESs,and how DESs are better than traditional solvents involving cost-ineffective and unsafe organic electrolytes and ionic liquids as well as inefficient aqueous systems due to low energy density for electrochemical energy storage applications.Then,a particular focus is placed on the various electrochemical applications of DESs,including their role in the electrolytes in batteries/supercapacitors,electropolishing and electrodeposition of metals,synthesis of electrode materials,recycling of electrodes,and their potential for use in CO_(2)capture.The review concludes by exploring the challenges,research gaps,and future potential of DESs in electrochemical applications,providing a comprehensive overview,and highlighting key considerations for their design and use.展开更多
Sinomenine is the main bio-active ingredient of Sinomenii Caulis and usually produced by solventextraction techniques. However, the extraction of sinomenine suffers from the lack of highly efficient and environmentall...Sinomenine is the main bio-active ingredient of Sinomenii Caulis and usually produced by solventextraction techniques. However, the extraction of sinomenine suffers from the lack of highly efficient and environmentally-benign solvents. In this work, deep eutectic solvents(DESs) based on fragrances were synthesized, hydrogen-bond donors(HBDs) and hydrogen-bond acceptors(HBAs) components of DESs were identified and their extraction ability for sinomenine was evaluated and the extraction conditions were optimized by single-factor and orthogonal design experiments. It was found that the hydrogen-bonding interaction between sinomenine and DESs was the main extraction driving force and there was no explicit relationship between the extraction ability and the hydrophobicity of the DESs. The DESs could be recycled and sinomenine could be recovered quantitatively via backextraction. High-purity sinomenine((95.0 ± 2.3)%) could be produced. These findings suggest that DESs are highly-effective solvents for the isolation of sinomenine and exhibit great potential for the extraction of other bio-active compounds.展开更多
Tetragonal barium titanate was synthesized from barium hydroxide octahydrate and titanium tetrachloride through a simple one-step hydrothermal method.The effect of different solvents on the crystal structure and morph...Tetragonal barium titanate was synthesized from barium hydroxide octahydrate and titanium tetrachloride through a simple one-step hydrothermal method.The effect of different solvents on the crystal structure and morphology of barium titanate nanoparticles during the hy-drothermal process was investigated.Except for ethylene glycol/water solvent,impurity-free barium titanate was synthesized in pure water,methanol/water,ethanol/water,and isopropyl alcohol/water mixed solvents.Compared with other alcohols,ethanol promotes the formation of a tetragonal structure.In addition,characterization studies confirm that particles synthesized in methanol/water,ethanol/water,and isopropyl al-cohol/water mixed solvents are smaller in size than those synthesized in pure water.In the case of alcohol-containing solvents,the particle size decreases in the order of isopropanol,ethanol,and methanol.Among all the media used in this study,ethanol/water is considered the optimum reaction media for barium titanate with high tetragonality(defined as the ratio of two lattice parameters c and a,c/a=1.0088)and small aver-age particle size(82 nm),which indicates its great application potential in multilayer ceramic capacitors.展开更多
Room temperature sputtered inorganic nickel oxide(NiO_(x))is one of the most promising hole transport layers(HTL)for perovskite-sillion 2-terminal tandem solar cells with the aid of ultrathin and compact organic layer...Room temperature sputtered inorganic nickel oxide(NiO_(x))is one of the most promising hole transport layers(HTL)for perovskite-sillion 2-terminal tandem solar cells with the aid of ultrathin and compact organic layers to passivate the surface defects.In this study,the aromatic solvent with different substituent groups was used to regulate the conformation of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)am ine](PTAA)layer.As a result,the single-junction perovskite solar cell(PSC)gained a power conversion efficiency(PCE)of 20.63%,contributing to a 27.21%efficiency for monolithic perovskite/silicon(double-side polished)2-terminal tandem solar cell,by applying the alkyl aromatic solvent to enhance theπ-πstacking of PTAA molecular chains.The tandem solar cell can maintain 95%initial efficiency after aging over 1000 h.This study provides a universal approach for improving the photovoltaic performance of NiO_(x)/polymer-based perovskite/silicon tandem solar cells and other single junction inverted PSCs.展开更多
Biomass is renewable, abundant, cheap, biocompatible, and biodegradable materials and has been used to produce chemicals, materials,energy, and fuels. However, most of the biomass, especially most of the biomass polym...Biomass is renewable, abundant, cheap, biocompatible, and biodegradable materials and has been used to produce chemicals, materials,energy, and fuels. However, most of the biomass, especially most of the biomass polymers are not soluble in common solvents, which hinders their pretreatment and conversion. Deep eutectic solvents(DESs) are environmental-friendly, cheap, and highly tunable, with high solubility,which renders them potential applications in biomass pretreatment and conversion. They could be used as solvents or catalysts and so on. This paper intends to review the application of DESs for the pretreatment of biomass and conversion of biomass to value-added products. We focus on the following topics related to biomass and DESs:(1) DESs for the pretreatment of biomass;(2) DESs for the dissolution and separation of biomass or extraction of chemicals from biomass;(3) DESs for biomass conversion;(4) Drawbacks, and recyclability of DESs for pretreatment and conversion of biomass.展开更多
Deep eutectic solvents(DESs) are a new class of green solvents analogous to ionic liquids due to their biodegradable capacity and low cost. However, the direct extractive desulfurization of diesel oil by DESs cannot m...Deep eutectic solvents(DESs) are a new class of green solvents analogous to ionic liquids due to their biodegradable capacity and low cost. However, the direct extractive desulfurization of diesel oil by DESs cannot meet the government's standard. In this work, amphiphilic polyoxometalates were synthesized and characterized by FT-IR and mass spectrometry.The oxidative desulfurization results showed that benzothiophene(BT) could be completely removed by employing a [(C_6H_(13))_3P(C_(14)H_(29))]_3PMo_(12)O_(40), DES(ChCl/2 Ac) and H_2O_2 system. It was also found that the organic cation of catalysts played a positive role in oxidative desulfurization. The reaction conditions, such as reaction temperature and time, the amount of catalyst and DES and H_2O_2/S(O/S) molar ratio, were optimized. Different sulfides were tested to determine the desulfurization selectivity of the optimal reaction system, and it was found that 97.2% of dibenzothiophene(DBT) could be removed followed by 80.7% of 4-MDBT and 76.0% of 4,6-DMDBT. After reaction, the IR spectra showed that the catalyst [(C_6H_(13))_3P(C_(14)H_(29))]_3PMo_(12)O_(40) was stable during the reaction process and the oxidative product was dibenzothiophene sulfone(DBTO_2). Furthermore, the catalyst can be regenerated and recycled for four runs with little loss of activity.展开更多
An analytical method for the quantification of residual solvents in annatto extracts, natural food colorants, was established using a static headspace gas chromatography (HSGC) coupled with a flame ionization detector...An analytical method for the quantification of residual solvents in annatto extracts, natural food colorants, was established using a static headspace gas chromatography (HSGC) coupled with a flame ionization detector (FID). As a sample diluent in a headspace sampling, dimethylformamide (DMF) was selected owing to its high capacity for dissolving both bixin-based and norbixin-based annatto extracts. The quantification of residual solvents was performed using the external standard method. The linearity of the calibration curves was assured with relative coefficients (R2) that were greater than 0.999. The recoveries of all standard solvents spiked in the annatto extracts were in the range from 95.1% to 107.1% to verify the accuracy and the relative standard deviation (RSD%) values (n = 3) were in the range from 0.57% to 3.31%. The quantification limits (QL) were sufficiently lower than the limits specified by Joint FAO/WHO Expert Committee on Food Additives (JECFA). With the established HSGC method, six residual solvents (methanol, ethanol, 2-propanol, acetone, ethyl acetate, and hexane) in 23 commercial annatto-extract products that consist of seven bixin-based and 16 norbixin-based products were quantified. The levels of residual ethyl acetate and hexane in all products were lower than the specified limits of JECFA. However, three samples of bixin-based products showed higher levels of residual 2-propanol (approximately 313.9 - 427.7 ppm) than the specified limit. Other bixin products also showed higher concentrations of residual methanol (approximately 166.6 - 394.7 ppm) and residual acetone (approximately 75.2 - 179.8 ppm) than the limits of JECFA. In the case of norbixin-based products, nine samples showed higher levels of residual acetone (approximately 42.6 - 139.5 ppm) than the limits of JECFA. This is the first survey of residual solvents in annatto extracts using the validated HSGC method.展开更多
The diffusion coefficients(Dapp) and the heterogeneous electron transfer rate constants(ks)for ferrocene in several polymer solvents were determined by using steady-stae voltammetry. Thetemperature dependence of the t...The diffusion coefficients(Dapp) and the heterogeneous electron transfer rate constants(ks)for ferrocene in several polymer solvents were determined by using steady-stae voltammetry. Thetemperature dependence of the two parameters indicates Arrhenius behavior. The polymer solventeffects on diffusion and electron transfer dynamics of ferrocene were展开更多
Deep eutectic solvents(DESs)have drawn a growing research interest for applications in a wide range of scientific and industrial arenas.However,a limited effort has been reported in the area of gas separation processe...Deep eutectic solvents(DESs)have drawn a growing research interest for applications in a wide range of scientific and industrial arenas.However,a limited effort has been reported in the area of gas separation processes and particularly the carbon dioxide capture.This study introduces a novel set of DESs that were prepared by complexing ethylenediamine(EDA),monoethanolamine(MEA),tetraethylenepentamine(TEPA),triethylenetetramine(TETA)and diethylenetriamine(DETA)as hydrogen bond donors to monoethanolamide hydrochloride(EAHC)salt as a hydrogen bond acceptor.The absorption capacity of CO2 was evaluated by exploiting a method based on measuring the pressure drop during the absorption process.The solubility of different DESs was studied at a temperature of 313.15 K and initial pressure of 0.8 MPa.The DES systems 1 EAHC:9 DETA,1 EAHC:9 TETA and 1 EAHC:9 TEPA achieved the highest CO2 solubility of 0.6611,0.6572 and 0.7017 mol CO2·(mole DES)-1 respectively.The results showed that CO2 solubility in the DESs increased with increasing the molar ratio of hydrogen bond donor.In addition,the CO2 solubility increased as the number of amine groups in the solvent increases,therefore,increasing the alkyl chain length in the DESs,resulted in increasing the CO2 solubility.FTIR analysis confirms the DES synthesis since no new functional group was identified.The FTIR spectra also revealed the carbamate formation in DES-CO2 mixtures.In addition,the densities and viscosities of the synthesized DESs were also measured.The CO2 initial investigation of reported DESs shows that these can be potential alternative for conventional solvents in CO2 capture processes.展开更多
The electron paramagnetic resonance spectra of the chelate-based ionic liquid[C_(10)mim][Cu(F_6-acac)_3]in different solvents have been obtained at 120 K.It was found that the values of the^(63)Cu hyperfine coupling c...The electron paramagnetic resonance spectra of the chelate-based ionic liquid[C_(10)mim][Cu(F_6-acac)_3]in different solvents have been obtained at 120 K.It was found that the values of the^(63)Cu hyperfine coupling constants(A_(IL))of[C_(10)mim][Cu(F_6-acac)_3]in molecular solvents were from 116 to 180 Gauss.Moreover,the A_(IL)values in general ionic liquids are more complicated,and two sets of peaks can often be observed in their electron paramagnetic resonance spectra.Based on the Kamlet-Taft parameters,relative permittivity,the experimental results were discussed in terms of solvation effect and coordination of the solvents.展开更多
Immobilization systems more frequently used are calcium alginate spheres. These biocatalysts have many potential applications in the immobilization of enzymes, prokaryotic cells, vegetal and animal cells, algae, organ...Immobilization systems more frequently used are calcium alginate spheres. These biocatalysts have many potential applications in the immobilization of enzymes, prokaryotic cells, vegetal and animal cells, algae, organelles and mixtures of these living components. Other applications of immobilized cells imply the use of non aqueous systems. Some bioconversions are carried out in the presence of solvents such as hexane acetone or acetonitrile, or mixtures water-solvents. The aim of this work was to investigate the behaviour of Ca-alginate spheres when put in contact with different solvents (water, diesel, ethanol, methanol, acetone, n-hexane, isopropyl alcohol, THF, acetonitrile, and toluene), or solvent-water mixtures (i.e., ethanol-water), regarding the resistance of the alginate spheres after days of contact. Calcium alginate particles suffered different damages, depending on the solvent they were put in contact. Water did not damaged the Ca-alginate structure with or without Ca present. On the other hand different solvents lost a proportion of volume, i.e., n-hexane (16%), methanol (19%), ethanol (19.5%), toluene (22%), diesel (34%), acetone (765), isopropyl alcohol (80%), THF and acetonitrile (total loss, total destruction). Nor the dielectric constant nor the polarity indexes were capable of explaining the difference on the volume loss or total sphere destruction, except for water-ethanol mixtures.展开更多
The surface tension and cenductivity of tetracthylarnmomum perfluorooctanesulfonate (TEPFOS) solu-tions in mixed solvents were determined The criticsl micelle concentrations (cmc) and surface adsorption of TEPFOS in v...The surface tension and cenductivity of tetracthylarnmomum perfluorooctanesulfonate (TEPFOS) solu-tions in mixed solvents were determined The criticsl micelle concentrations (cmc) and surface adsorption of TEPFOS in various solvents (Dimetbylsulfoxlde and DMSO, formamide and FA, and DMSO-H2O and FA H2O mixtures) were calculated from the above experimental date. The results show that the surface activity of TEPFOS is much higher than that of typical hydrocarbon surfactant, sodium dodecylsulfate (SDS); the melecalar interaction (in terms of colubility araneter or surface tension) of solvent is the decisive factor in sffecting the cmc of TEPFOS , in the apretic solvent DMSO, the value of entropy change during micelliza-tion of TEPFOS may beecme subsantially negative; the surfaof adsorption amount of TEPFOS is the largest in H2O, smaller in FA , and the smallest in DMSO.展开更多
A series of novel binary deep eutectic solvents(DESs)composed of choline chloride(ChCl)and formic acid(HCOOH)with different molar ratios have been successfully synthesized and applied in extractive desulfurization(EDS...A series of novel binary deep eutectic solvents(DESs)composed of choline chloride(ChCl)and formic acid(HCOOH)with different molar ratios have been successfully synthesized and applied in extractive desulfurization(EDS).Keggin-type polyoxometallate ionic liquid[TTPh]_(3)PW_(12)O_(40) was prepared and used as catalyst to enhance the EDS capacity by means of photocatalytic oxidative process.Both of the DESs and[TTPh]_(3)PW_(12)O_(40) ionic liquid catalyst were characterized in detail by Fourier transform infrared spectroscopy spectra(FT-IR),elemental analysis,and X-ray photoelectron spectroscopy(XPS).It was found that the molar ratios of Ch Cl:HCOOH had a major impact on desulfurization performance,and the optimal desulfurization capacity 96.5%was obtained by ChCl/5 HCOOH.Besides dibenzothiophene(DBT),the desulfurization efficiencies of 4-methylbenzothiophene(4-MDBT)and 4,6-dimethyldibenzothiophene(4,6-DMDBT),two kinds of DBT derivatives,were also investigated under the same experimental conditions.Moreover,the free radical scavenging experiments manifested that superoxide radical(·O_(2)^(-)) and hole(h^(+)) played important roles in the desulfurization system.After further analysis of the oxidation products by gas chromatography-mass spectrometry(GC–MS),the possible reaction mechanism was proposed.Thus,photocatalytic oxidative has been proved to be one of the efficient approaches for enhancing the extractive desulfurization performance in DES.展开更多
Metal halide perovskites(MHPs) are gaining increasing attention as low-cost, high-performance semiconductors for optoelectronics. In particular, their solution processing is compatible with the largescale manufacturin...Metal halide perovskites(MHPs) are gaining increasing attention as low-cost, high-performance semiconductors for optoelectronics. In particular, their solution processing is compatible with the largescale manufacturing of thin-film devices, including solar cells and light-emitting diodes.Understanding the coordination chemistry in precursor-solvent solution and atomistic mechanisms of film formation is of great importance for optimizing the optoelectronic properties of the final films.Using the methylammonium lead triiodide(MAPbI_(3)) as an example, we study the complex evolution of the molecular species from the solution to the initial stage of the crystallization by using a combination of density functional theory(DFT) calculations and ab-initio molecular dynamics(AIMD) simulations. We focus on the widely employed solvents DMSO and DMF, analyze the structures and energies of the iodoplumbate complexes in the form of simple complex of [PbI_(m)L_(n)]^(2-m))_(x) and polymeric iodoplumbates of([PbI_(m)L_(n)]^(2-m))_(x). Based on the calculated formation enthalpies, we propose reaction schemes of MAPbI_(3) formation in DMSO, DMF and DMF-DMSO binary solvent and explain the advantages of the binary solvent.We highlight the important role of NH...O hydrogen bonds in the formation of iodoplumbates monomers.Our calculations indicate unbalanced reaction energies at several elementary reaction steps in either DMF(formation of [PbI_(4)L_(n)]^(2-) being highly favourable) or DMSO(formation of [PbI_(5)L_(n)]^(3- )being retarded).Mixing a small amount of DMSO in DMF gives rise to a better balance in the energies and, therefore,potentially better equilibria in the overall crystallization process and better quality of the final perovskite films.展开更多
基金financially supported by Shanxi Province Natural Science Foundation of China(20210302123167)NSFC-Shanxi joint fund for coal-based low carbon(U1610223)Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(2021SX-TD006).
文摘Carbazole is an irreplaceable basic organic chemical raw material and intermediate in industry.The separation of carbazole from anthracene oil by environmental benign solvents is important but still a challenge in chemical engineering.Deep eutectic solvents (DESs) as a sustainable green separation solvent have been proposed for the separation of carbazole from model anthracene oil.In this research,three quaternary ammonium-based DESs were prepared using ethylene glycol (EG) as hydrogen bond donor and tetrabutylammonium chloride (TBAC),tetrabutylammonium bromide or choline chloride as hydrogen bond acceptors.To explore their extraction performance of carbazole,the conductor-like screening model for real solvents (COSMO-RS) model was used to predict the activity coefficient at infinite dilution (γ^(∞)) of carbazole in DESs,and the result indicated TBAC:EG (1:2) had the stronger extraction ability for carbazole due to the higher capacity at infinite dilution (C^(∞)) value.Then,the separation performance of these three DESs was evaluated by experiments,and the experimental results were in good agreement with the COSMO-RS prediction results.The TBAC:EG (1:2) was determined as the most promising solvent.Additionally,the extraction conditions of TBAC:EG (1:2) were optimized,and the extraction efficiency,distribution coefficient and selectivity of carbazole could reach up to 85.74%,30.18 and 66.10%,respectively.Moreover,the TBAC:EG (1:2) could be recycled by using environmentally friendly water as antisolvent.In addition,the separation performance of TBAC:EG (1:2) was also evaluated by real crude anthracene,the carbazole was obtained with purity and yield of 85.32%,60.27%,respectively.Lastly,the extraction mechanism was elucidated byσ-profiles and interaction energy analysis.Theoretical calculation results showed that the main driving force for the extraction process was the hydrogen bonding ((N–H...Cl) and van der Waals interactions (C–H...O and C–H...π),which corresponding to the blue and green isosurfaces in IGMH analysis.This work presented a novel method for separating carbazole from crude anthracene oil,and will provide an important reference for the separation of other high value-added products from coal tar.
基金financially supported by the National Natural Science Foundation of China (21905069, U21A20307, 22208073)the Shenzhen Science and Technology Innovation Committee (ZDSYS20190902093220279, KQTD20170809110344233, GXWD20201230155427003-20200821181245001, GXWD20201230155427003-202008211 81809001, ZX20200151)the Department of Science and Technology of Guangdong Province (2020A1515110879)。
文摘The development of green solvents for enhancing aqueous solubility of drug curcumin remains a challenge. This study explores the enhancing effect of deep eutectic solvents(DESs) on the aqueous solubility of curcumin(CUR) via experiment and theoretical calculation. Choline chloride-based DESs with polyols 1,2-propanediol(1,2-PDO), 1,3-propanediol, ethylene glycol, and glycerol as hydrogen bond donors were prepared and used as co-solvents. The CUR aqueous solubility increased with increasing the DESs content at temperature of 303.15-318.15 K, especially in aqueous ChCl/1,2-PDO(mole ratio 1:4) solutions. The positive apparent molar volume values and reduced density gradient analysis confirmed the existence of strong interactions between CUR and solvent. The van der Waals interactions and hydrogen bonding coexisted in DESs monomer retained the stability of DESs structure after introducing CUR. Moreover,the lower interaction energy of DESs…CUR system than that of the counterpart DESs further proved the strong interaction between CUR and DESs. The lowest interaction energy of ChCl/1,2-PDO…CUR system indicated that this system was the most stable and ChCl/1,2-PDO was promising for CUR dissolution.This work provides efficient solvents for utilizing curcumin, contributing to a deep insight into the interactions between DES and CUR at the molecular level, and the role of DESs on enhancing drugs solubility.
基金financial support from the graduate council of the University of Tabriz,Tabriz,Iran.
文摘Important efforts have been made over the past years to improve the drug acts,which leads to the discovery of novel drug preparations and delivery systems.The optimal design of such processes requires a molecular-level understanding of the interactions between drug molecules and biological membranes.The thermodynamic investigation provides deep and complete knowledge of interactions and the choice of appropriate and suitable production compounds in pharmaceutical fields.Particularly,the analysis of drugs+co-solvents in aqueous media is the central issue in many types of research because they exert their impact by interacting with biological membranes.This work is aimed to measure the density and speed of sound for the thiamine hydrochloride in water+deep eutectic solvents(DESs)mixtures(choline chloride/urea,choline chloride/ethylene glycol and choline chloride/glycerol)at temperature range(293.15-308.15)K.By correlation of the evaluated parameters in some standard relations,the partial molar parameters i.e.apparent molar volumes,Vφ,m,and apparent molar isentropic compression,κ_(s,φ,m),are calculated.In addition,apparent molar isobaric expansion,E^(0)_(φ,m),and Hepler’s constant are computed from the density and speed of sound data.For fitting the experimental Vφ,m andκ_(s,φ,m)the Redlich-Meyer equation was employed that the important quantities;standard partial molar volume,V^(0)_(m),and partial molar isentropic compression,κφ,m0,were obtained.The thermodynamic analysis of the studied system also plays a crucial role in the pharmaceutical industry.
基金support from the National Natural Science Foundation of China(Nos.52120105007,51834010)the National Science Fund for Distinguished Young Scholars(No.52222403).
文摘Fracturing fluid property play a critical role in developing unconventional reservoirs.Deep eutectic solvents(DESs)show fascinating potential for property improvement of clean fracturing fluids(CFFs)due to their low-price,low-toxicity,chemical stability and flexible designability.In this work,DESs were synthesized by mixing hydrogen bond acceptors(HBAs)and a given hydrogen bond donor(HBD)to explore their underlying influence on CFF properties based on the intermolecular interactions.The hydrogen-bonding,van der Waals and electrostatic interactions between DES components and surfactants improved the CFF properties by promoting the arrangement of surfactants at interface and enhancing the micelle network strength.The HBD enhanced the resistance of CFF for Ca^(2+) due to coordination-bonding interaction.The DESs composed of choline chloride(ChCl)and malonic acid show great enhancement for surface,rheology,temperature resistance,salt tolerance,drag reduction,and gel-breaking performance of CFFs.The DESs also improved the gel-breaking CFF-oil interactions,increasing the imbibition efficiencies to 44.2%in 74 h.Adjusting HBAs can effectively strengthen the intermolecular interactions(e.g.,HBA-surfactant and HBD-surfactant interactions)to improve CFF properties.The DESs developed in this study provide a novel strategy to intensify CFF properties.
文摘Solvents are generally used to reduce the viscosity of heavy crude oil and ultimately enhance oil recovery.Recently,a new method has been introduced where nanoparticles(NPs)are exploited to induce enhanced oil recovery owing to their ability to improve the mobility ratio,dampen the interfacial tension,and alter rock wett-ability.This study investigated the integration of nano-alumina(Al_(2)O_(3))NPs with an n-hexane solvent.In parti-cular,a Brookfield viscometer has been used to measure the crude oil viscosity and it has been found that NPs can effectively lead to a significant decrease in the overall oil viscosity(70 cp using the solvent only,45 cp when NPs are added).
文摘Extraction of castor oil from castor seeds was investigated using different green solvents which include d-limonene, p-cymene, α-pinene, ethanol, and furfural at the temperature range of (323 - 413) K. The Soxhlet extraction method was employed to investigate the effect of temperature at atmospheric pressure. The focus of the study was to investigate a potential green solvent that can produce the high yields compared to the traditional solvent (hexane). The results show that at the average time of 3 hours and 30 minutes, the castor oil yield for green solvents were ranked as furfural (47.13%) > ethanol (45.37%) > p-cymene (39.15%) > d-limonene (39.13%) > α-pinene (38.11%). These castor oil yields were obtained at optimum temperatures for each green solvent. The castor oil yields were compared to the yield of hexane (31.36%) at same average time. The green solvents were recovered by using simple distillation, except furfural which was difficult to be recovered.
文摘As the demand for sustainable energy sources continues to rise,the need for efficient and reliable energy storage systems becomes crucial.In order to effectively store and distribute renewable energy,new and innovative solutions must be explored.This review examines the deep eutectic solvents(DESs)as a green,safe,and affordable solution for the electrochemical energy storage and conversion field,offering tremendous opportunities and a promising future.DESs are a class of environment-friendly solvents known for their low toxicity and unique properties,such as their good conductivity,high thermal stability,and nonflammability.This review explores the fundamentals,preparations,and various interactions that often predominate in the formation of DESs,the properties of DESs,and how DESs are better than traditional solvents involving cost-ineffective and unsafe organic electrolytes and ionic liquids as well as inefficient aqueous systems due to low energy density for electrochemical energy storage applications.Then,a particular focus is placed on the various electrochemical applications of DESs,including their role in the electrolytes in batteries/supercapacitors,electropolishing and electrodeposition of metals,synthesis of electrode materials,recycling of electrodes,and their potential for use in CO_(2)capture.The review concludes by exploring the challenges,research gaps,and future potential of DESs in electrochemical applications,providing a comprehensive overview,and highlighting key considerations for their design and use.
基金financially supported by the National Natural Science Foundation of China ( 21307028)Foundation of Henan province (202102310614)+1 种基金the Fundamental Research Funds for the Universities of Henan Province (NSFRF210428)the Foundation of Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University (KJS2016)。
文摘Sinomenine is the main bio-active ingredient of Sinomenii Caulis and usually produced by solventextraction techniques. However, the extraction of sinomenine suffers from the lack of highly efficient and environmentally-benign solvents. In this work, deep eutectic solvents(DESs) based on fragrances were synthesized, hydrogen-bond donors(HBDs) and hydrogen-bond acceptors(HBAs) components of DESs were identified and their extraction ability for sinomenine was evaluated and the extraction conditions were optimized by single-factor and orthogonal design experiments. It was found that the hydrogen-bonding interaction between sinomenine and DESs was the main extraction driving force and there was no explicit relationship between the extraction ability and the hydrophobicity of the DESs. The DESs could be recycled and sinomenine could be recovered quantitatively via backextraction. High-purity sinomenine((95.0 ± 2.3)%) could be produced. These findings suggest that DESs are highly-effective solvents for the isolation of sinomenine and exhibit great potential for the extraction of other bio-active compounds.
基金supported by Chongqing Newcent New Materials Co.,Ltd.,China (No.2021GKF-0708).
文摘Tetragonal barium titanate was synthesized from barium hydroxide octahydrate and titanium tetrachloride through a simple one-step hydrothermal method.The effect of different solvents on the crystal structure and morphology of barium titanate nanoparticles during the hy-drothermal process was investigated.Except for ethylene glycol/water solvent,impurity-free barium titanate was synthesized in pure water,methanol/water,ethanol/water,and isopropyl alcohol/water mixed solvents.Compared with other alcohols,ethanol promotes the formation of a tetragonal structure.In addition,characterization studies confirm that particles synthesized in methanol/water,ethanol/water,and isopropyl al-cohol/water mixed solvents are smaller in size than those synthesized in pure water.In the case of alcohol-containing solvents,the particle size decreases in the order of isopropanol,ethanol,and methanol.Among all the media used in this study,ethanol/water is considered the optimum reaction media for barium titanate with high tetragonality(defined as the ratio of two lattice parameters c and a,c/a=1.0088)and small aver-age particle size(82 nm),which indicates its great application potential in multilayer ceramic capacitors.
基金supported by the National Key R&D Program of China(2018YFB1500103)the National Natural Science Foundation of China(62104082)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(2022A1515010746,2022A1515011228)the Science and Technology Program of Guangzhou(202201010458)。
文摘Room temperature sputtered inorganic nickel oxide(NiO_(x))is one of the most promising hole transport layers(HTL)for perovskite-sillion 2-terminal tandem solar cells with the aid of ultrathin and compact organic layers to passivate the surface defects.In this study,the aromatic solvent with different substituent groups was used to regulate the conformation of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)am ine](PTAA)layer.As a result,the single-junction perovskite solar cell(PSC)gained a power conversion efficiency(PCE)of 20.63%,contributing to a 27.21%efficiency for monolithic perovskite/silicon(double-side polished)2-terminal tandem solar cell,by applying the alkyl aromatic solvent to enhance theπ-πstacking of PTAA molecular chains.The tandem solar cell can maintain 95%initial efficiency after aging over 1000 h.This study provides a universal approach for improving the photovoltaic performance of NiO_(x)/polymer-based perovskite/silicon tandem solar cells and other single junction inverted PSCs.
基金supported by the National Natural Science Foundation of China(21773307)
文摘Biomass is renewable, abundant, cheap, biocompatible, and biodegradable materials and has been used to produce chemicals, materials,energy, and fuels. However, most of the biomass, especially most of the biomass polymers are not soluble in common solvents, which hinders their pretreatment and conversion. Deep eutectic solvents(DESs) are environmental-friendly, cheap, and highly tunable, with high solubility,which renders them potential applications in biomass pretreatment and conversion. They could be used as solvents or catalysts and so on. This paper intends to review the application of DESs for the pretreatment of biomass and conversion of biomass to value-added products. We focus on the following topics related to biomass and DESs:(1) DESs for the pretreatment of biomass;(2) DESs for the dissolution and separation of biomass or extraction of chemicals from biomass;(3) DESs for biomass conversion;(4) Drawbacks, and recyclability of DESs for pretreatment and conversion of biomass.
基金financially supported by the National Natural Science Foundation of China (Nos. 21506080 and 21766007)Natural Science Foundation of Jiangsu Province (No. BK20150485)+1 种基金Advanced Talents of Jiangsu University (No. 15JDG053)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Deep eutectic solvents(DESs) are a new class of green solvents analogous to ionic liquids due to their biodegradable capacity and low cost. However, the direct extractive desulfurization of diesel oil by DESs cannot meet the government's standard. In this work, amphiphilic polyoxometalates were synthesized and characterized by FT-IR and mass spectrometry.The oxidative desulfurization results showed that benzothiophene(BT) could be completely removed by employing a [(C_6H_(13))_3P(C_(14)H_(29))]_3PMo_(12)O_(40), DES(ChCl/2 Ac) and H_2O_2 system. It was also found that the organic cation of catalysts played a positive role in oxidative desulfurization. The reaction conditions, such as reaction temperature and time, the amount of catalyst and DES and H_2O_2/S(O/S) molar ratio, were optimized. Different sulfides were tested to determine the desulfurization selectivity of the optimal reaction system, and it was found that 97.2% of dibenzothiophene(DBT) could be removed followed by 80.7% of 4-MDBT and 76.0% of 4,6-DMDBT. After reaction, the IR spectra showed that the catalyst [(C_6H_(13))_3P(C_(14)H_(29))]_3PMo_(12)O_(40) was stable during the reaction process and the oxidative product was dibenzothiophene sulfone(DBTO_2). Furthermore, the catalyst can be regenerated and recycled for four runs with little loss of activity.
文摘An analytical method for the quantification of residual solvents in annatto extracts, natural food colorants, was established using a static headspace gas chromatography (HSGC) coupled with a flame ionization detector (FID). As a sample diluent in a headspace sampling, dimethylformamide (DMF) was selected owing to its high capacity for dissolving both bixin-based and norbixin-based annatto extracts. The quantification of residual solvents was performed using the external standard method. The linearity of the calibration curves was assured with relative coefficients (R2) that were greater than 0.999. The recoveries of all standard solvents spiked in the annatto extracts were in the range from 95.1% to 107.1% to verify the accuracy and the relative standard deviation (RSD%) values (n = 3) were in the range from 0.57% to 3.31%. The quantification limits (QL) were sufficiently lower than the limits specified by Joint FAO/WHO Expert Committee on Food Additives (JECFA). With the established HSGC method, six residual solvents (methanol, ethanol, 2-propanol, acetone, ethyl acetate, and hexane) in 23 commercial annatto-extract products that consist of seven bixin-based and 16 norbixin-based products were quantified. The levels of residual ethyl acetate and hexane in all products were lower than the specified limits of JECFA. However, three samples of bixin-based products showed higher levels of residual 2-propanol (approximately 313.9 - 427.7 ppm) than the specified limit. Other bixin products also showed higher concentrations of residual methanol (approximately 166.6 - 394.7 ppm) and residual acetone (approximately 75.2 - 179.8 ppm) than the limits of JECFA. In the case of norbixin-based products, nine samples showed higher levels of residual acetone (approximately 42.6 - 139.5 ppm) than the limits of JECFA. This is the first survey of residual solvents in annatto extracts using the validated HSGC method.
文摘The diffusion coefficients(Dapp) and the heterogeneous electron transfer rate constants(ks)for ferrocene in several polymer solvents were determined by using steady-stae voltammetry. Thetemperature dependence of the two parameters indicates Arrhenius behavior. The polymer solventeffects on diffusion and electron transfer dynamics of ferrocene were
基金Sultan Qaboos University for providing financial。
文摘Deep eutectic solvents(DESs)have drawn a growing research interest for applications in a wide range of scientific and industrial arenas.However,a limited effort has been reported in the area of gas separation processes and particularly the carbon dioxide capture.This study introduces a novel set of DESs that were prepared by complexing ethylenediamine(EDA),monoethanolamine(MEA),tetraethylenepentamine(TEPA),triethylenetetramine(TETA)and diethylenetriamine(DETA)as hydrogen bond donors to monoethanolamide hydrochloride(EAHC)salt as a hydrogen bond acceptor.The absorption capacity of CO2 was evaluated by exploiting a method based on measuring the pressure drop during the absorption process.The solubility of different DESs was studied at a temperature of 313.15 K and initial pressure of 0.8 MPa.The DES systems 1 EAHC:9 DETA,1 EAHC:9 TETA and 1 EAHC:9 TEPA achieved the highest CO2 solubility of 0.6611,0.6572 and 0.7017 mol CO2·(mole DES)-1 respectively.The results showed that CO2 solubility in the DESs increased with increasing the molar ratio of hydrogen bond donor.In addition,the CO2 solubility increased as the number of amine groups in the solvent increases,therefore,increasing the alkyl chain length in the DESs,resulted in increasing the CO2 solubility.FTIR analysis confirms the DES synthesis since no new functional group was identified.The FTIR spectra also revealed the carbamate formation in DES-CO2 mixtures.In addition,the densities and viscosities of the synthesized DESs were also measured.The CO2 initial investigation of reported DESs shows that these can be potential alternative for conventional solvents in CO2 capture processes.
基金supported by the National Natural Science Foundation,China(No.21573196)the Fundamental Research Funds for the Central Universities,Chinathe National High Technology Research and the National Natural Science Foundation,China(No.22073081)。
文摘The electron paramagnetic resonance spectra of the chelate-based ionic liquid[C_(10)mim][Cu(F_6-acac)_3]in different solvents have been obtained at 120 K.It was found that the values of the^(63)Cu hyperfine coupling constants(A_(IL))of[C_(10)mim][Cu(F_6-acac)_3]in molecular solvents were from 116 to 180 Gauss.Moreover,the A_(IL)values in general ionic liquids are more complicated,and two sets of peaks can often be observed in their electron paramagnetic resonance spectra.Based on the Kamlet-Taft parameters,relative permittivity,the experimental results were discussed in terms of solvation effect and coordination of the solvents.
文摘Immobilization systems more frequently used are calcium alginate spheres. These biocatalysts have many potential applications in the immobilization of enzymes, prokaryotic cells, vegetal and animal cells, algae, organelles and mixtures of these living components. Other applications of immobilized cells imply the use of non aqueous systems. Some bioconversions are carried out in the presence of solvents such as hexane acetone or acetonitrile, or mixtures water-solvents. The aim of this work was to investigate the behaviour of Ca-alginate spheres when put in contact with different solvents (water, diesel, ethanol, methanol, acetone, n-hexane, isopropyl alcohol, THF, acetonitrile, and toluene), or solvent-water mixtures (i.e., ethanol-water), regarding the resistance of the alginate spheres after days of contact. Calcium alginate particles suffered different damages, depending on the solvent they were put in contact. Water did not damaged the Ca-alginate structure with or without Ca present. On the other hand different solvents lost a proportion of volume, i.e., n-hexane (16%), methanol (19%), ethanol (19.5%), toluene (22%), diesel (34%), acetone (765), isopropyl alcohol (80%), THF and acetonitrile (total loss, total destruction). Nor the dielectric constant nor the polarity indexes were capable of explaining the difference on the volume loss or total sphere destruction, except for water-ethanol mixtures.
文摘The surface tension and cenductivity of tetracthylarnmomum perfluorooctanesulfonate (TEPFOS) solu-tions in mixed solvents were determined The criticsl micelle concentrations (cmc) and surface adsorption of TEPFOS in various solvents (Dimetbylsulfoxlde and DMSO, formamide and FA, and DMSO-H2O and FA H2O mixtures) were calculated from the above experimental date. The results show that the surface activity of TEPFOS is much higher than that of typical hydrocarbon surfactant, sodium dodecylsulfate (SDS); the melecalar interaction (in terms of colubility araneter or surface tension) of solvent is the decisive factor in sffecting the cmc of TEPFOS , in the apretic solvent DMSO, the value of entropy change during micelliza-tion of TEPFOS may beecme subsantially negative; the surfaof adsorption amount of TEPFOS is the largest in H2O, smaller in FA , and the smallest in DMSO.
基金financially supported by the National Natural Science Foundation of China(No.21808091)Natural Science Foundation of Jiangsu Province(Nos.BK20200896,BK20190243)+2 种基金Key Laboratory of Tropical Medicinal Plant Chemistry of Ministry of Education,Hainan Normal University(20150376)China Postdoctoral Foundation(No.2020M671365)the Student Innovation and Entrepreneurship Training Program(202010299457X)。
文摘A series of novel binary deep eutectic solvents(DESs)composed of choline chloride(ChCl)and formic acid(HCOOH)with different molar ratios have been successfully synthesized and applied in extractive desulfurization(EDS).Keggin-type polyoxometallate ionic liquid[TTPh]_(3)PW_(12)O_(40) was prepared and used as catalyst to enhance the EDS capacity by means of photocatalytic oxidative process.Both of the DESs and[TTPh]_(3)PW_(12)O_(40) ionic liquid catalyst were characterized in detail by Fourier transform infrared spectroscopy spectra(FT-IR),elemental analysis,and X-ray photoelectron spectroscopy(XPS).It was found that the molar ratios of Ch Cl:HCOOH had a major impact on desulfurization performance,and the optimal desulfurization capacity 96.5%was obtained by ChCl/5 HCOOH.Besides dibenzothiophene(DBT),the desulfurization efficiencies of 4-methylbenzothiophene(4-MDBT)and 4,6-dimethyldibenzothiophene(4,6-DMDBT),two kinds of DBT derivatives,were also investigated under the same experimental conditions.Moreover,the free radical scavenging experiments manifested that superoxide radical(·O_(2)^(-)) and hole(h^(+)) played important roles in the desulfurization system.After further analysis of the oxidation products by gas chromatography-mass spectrometry(GC–MS),the possible reaction mechanism was proposed.Thus,photocatalytic oxidative has been proved to be one of the efficient approaches for enhancing the extractive desulfurization performance in DES.
基金funding by the Computational Sciences for Energy Research (CSER) tenure track program of Shell and NWO (Project No. 15CST04-2)funding by the Computational Sciences for Energy Research (CSER) tenure track program of Shell and NWO(Project No. 15CST04-2)+1 种基金funding support from the NWO START-UP from the Netherlandsthe NWO START-UP from the Netherlands。
文摘Metal halide perovskites(MHPs) are gaining increasing attention as low-cost, high-performance semiconductors for optoelectronics. In particular, their solution processing is compatible with the largescale manufacturing of thin-film devices, including solar cells and light-emitting diodes.Understanding the coordination chemistry in precursor-solvent solution and atomistic mechanisms of film formation is of great importance for optimizing the optoelectronic properties of the final films.Using the methylammonium lead triiodide(MAPbI_(3)) as an example, we study the complex evolution of the molecular species from the solution to the initial stage of the crystallization by using a combination of density functional theory(DFT) calculations and ab-initio molecular dynamics(AIMD) simulations. We focus on the widely employed solvents DMSO and DMF, analyze the structures and energies of the iodoplumbate complexes in the form of simple complex of [PbI_(m)L_(n)]^(2-m))_(x) and polymeric iodoplumbates of([PbI_(m)L_(n)]^(2-m))_(x). Based on the calculated formation enthalpies, we propose reaction schemes of MAPbI_(3) formation in DMSO, DMF and DMF-DMSO binary solvent and explain the advantages of the binary solvent.We highlight the important role of NH...O hydrogen bonds in the formation of iodoplumbates monomers.Our calculations indicate unbalanced reaction energies at several elementary reaction steps in either DMF(formation of [PbI_(4)L_(n)]^(2-) being highly favourable) or DMSO(formation of [PbI_(5)L_(n)]^(3- )being retarded).Mixing a small amount of DMSO in DMF gives rise to a better balance in the energies and, therefore,potentially better equilibria in the overall crystallization process and better quality of the final perovskite films.
