Organic solar cells(OSCs)have gained conspicuous progress during the past few decades due to the development of materials and upgrading of the device structure.The power conversion efficiency(PCE)of the single-junctio...Organic solar cells(OSCs)have gained conspicuous progress during the past few decades due to the development of materials and upgrading of the device structure.The power conversion efficiency(PCE)of the single-junction device had surpassed 19%.The cathode interface layer(CIL),by optimizing the connection between the active layer and the cathode electrode,has become a momentous part to strengthen the performances of the OSCs.Simultaneously,CIL is also indispensable to illustrating the working mechanism of OSCs and enhancing the stability of the OSCs.In this essay,hybrid CILs in OSCs have been summarized.Firstly,the advancement and operating mechanism of OSCs,and the effects and relevant design rules of CIL are briefly concluded;secondly,the significant influence of CIL on enhancing the stability and PCE of OSCs is presented;thirdly,the characteristics of organic hybrid CIL and organic-inorganic hybrid CIL are introduced.Finally,the conclusion and outlook of CIL are summarized.展开更多
Metal–organic gel(MOG)derived composites are promising multi-functional materials due to their alterable composition,identifiable chemical homogeneity,tunable shape,and porous structure.Herein,stable metal–organic h...Metal–organic gel(MOG)derived composites are promising multi-functional materials due to their alterable composition,identifiable chemical homogeneity,tunable shape,and porous structure.Herein,stable metal–organic hydrogels are prepared by regulating the complexation effect,solution polarity and curing speed.Meanwhile,collagen peptide is used to facilitate the fabrication of a porous aerogel with excellent physical properties as well as the homogeneous dispersion of magnetic particles during calcination.Subsequently,two kinds of heterometallic magnetic coupling systems are obtained through the application of Kirkendall effect.FeCo/nitrogen-doped carbon(NC)aerogel demonstrates an ultra-strong microwave absorption of−85 dB at an ultra-low loading of 5%.After reducing the time taken by atom shifting,a FeCo/Fe3O4/NC aerogel containing virus-shaped particles is obtained,which achieves an ultra-broad absorption of 7.44 GHz at an ultra-thin thickness of 1.59 mm due to the coupling effect offered by dual-soft-magnetic particles.Furthermore,both aerogels show excellent thermal insulation property,and their outstanding radar stealth performances in J-20 aircraft are confirmed by computer simulation technology.The formation mechanism of MOG is also discussed along with the thermal insulation and electromagnetic wave absorption mechanism of the aerogels,which will enable the development and application of novel and lightweight stealth coatings.展开更多
The synthesis of Bi_2S_3 hierarchical nanostructure was reported by a solvothermal reaction using ethylene disulfhydrate as the sulfur source and chelating reagent. The as-synthesized samples were characterized by X-r...The synthesis of Bi_2S_3 hierarchical nanostructure was reported by a solvothermal reaction using ethylene disulfhydrate as the sulfur source and chelating reagent. The as-synthesized samples were characterized by X-ray diffraction(XRD), Raman, X-ray photoelectron spectroscopy(XPS), scanning electron microscopy(SEM) and photoluminescence(PL). The XRD, Raman, and XPS data confirmed that the as-synthesized sample belongs to orthorhombic phase Bi_2S_3. The SEM observations displayed that Bi_2S_3 hierarchical nanostructure assembled from nanorods. A 410 nm ultraviolet photoluminescence(PL) emission of as-synthesized Bi_2S_3 was observed when the sample was excited with wavelength of 320-330 nm. The Bi_2S_3 hierarchical nanostructure also shows a significant enhancement of photocatalytic capability toward degrading methyl orange(MO) under UV light, the photodegradation of MO reaches 95% within 180 min.展开更多
Herein,Co_(2)P nanorods(NRs)with exposure to high-index facets(HIFs)were prepared by a special assembly-calcination method using thioacetamide(TAA)as a structure-directing reagent.The analysis of adsorption energies o...Herein,Co_(2)P nanorods(NRs)with exposure to high-index facets(HIFs)were prepared by a special assembly-calcination method using thioacetamide(TAA)as a structure-directing reagent.The analysis of adsorption energies of S atoms on different facets as well as the surface energies of Co_(2)P indicate that the HIFs become more stable after adsorbing S atoms.With rich unsaturated sites on HIFs,the photochemical reduction rate of CO_(2)over Co_(2)P NRs is 14.5 mmol h^(-1)g^(-1)for the production of CO within 3 h.The analysis of electron transfer,bond lengths,bond angles and adsorption energies indicate that the CO_(2)molecules are more easily adsorbed and activated on the HIFs.The free energy calculations and d band theory demonstrate that the HIFs are conducive to reducing the formation energy barriers as well as improving the stability of the intermediate^(*)COOH,then enhancing the catalytic performance of CO_(2)reduction.展开更多
Electrosynthesis has recently attracted intensive research attentions and holds great potential in implementing scalable green synthesis thanks to more and more readily accessible renewable electric energy.
Oxygen vacancy plays vital roles in regulating the electronic and charge distribution of the oxygen deficient materials.Herein,abundant oxygen vacancies are created during assembling the two-dimensional(2D)ultra-thin ...Oxygen vacancy plays vital roles in regulating the electronic and charge distribution of the oxygen deficient materials.Herein,abundant oxygen vacancies are created during assembling the two-dimensional(2D)ultra-thin Bi_(2)MoO_(6) nanoflakes into three dimensional(3D)Bi_(2)MoO_(6) nanospheres,resulting in significantly improved performance for photocatalytical conversion of CO_(2) into liquid hydrocarbons.The increased performance is contributed by two primary sites,namely the abundant oxygen vacancy and the exposed molybdenum(Mo)atom induced by oxygen-migration,as revealed by the theoretical calculation.The oxygen vacancy(Ov)and uncovered Mo atom serving as dual binding sites for trapping CO_(2) molecules render the synchronous fixation-reduction process,resulting in the decline of activation energy for CO_(2) reduction from 2.15 eV on bulk Bi_(2)MoO_(6) to 1.42 eV on Ov-rich Bi_(2)MoO_(6).Such a striking decrease in the activation energy induces the efficient selective generation of liquid hydrocarbons,especially the methanol(C_(2)H_(5) OH)and ethanol(CH_(3) OH).The yields of CH_(3) OH and C_(2)H_(5) OH over the optimal Ov-Bi_(2)MoO_(6) is high up to 106.5 and 10.3μmol g^(-1) respectively,greatly outperforming that on the Bulk-Bi_(2)MoO_(6).展开更多
In this paper,sulfonic groups functionalized annealed bio-based carbon microspheres loaded polytetrafluoroethylene(A-BCMSs-SO_(3)H@PTFE)fibers with high activity,high stability,and easy regeneration were successfully ...In this paper,sulfonic groups functionalized annealed bio-based carbon microspheres loaded polytetrafluoroethylene(A-BCMSs-SO_(3)H@PTFE)fibers with high activity,high stability,and easy regeneration were successfully fabricated by a simple method using low-cost raw materials.The characterization results showed that the annealed biomass carbon microspheres derived from waste Camellia oleifera shells were evenly distributed on the polytetrafluoroethylene fibers and the sulfonic groups can be successfully loaded on the surface of annealed biomass carbon microspheres by room temperature sulfonation.Subsequently,the as-prepared A-BCMSs-SO_(3)H@PTFE fibers were applied to the acidcatalyzed synthesis of liquid biofuel 5-ethoxymethylfurfural.The catalytic experiment results indicated that the annealing temperature and time during catalyst preparation have a significant effect on the activity and selectivity of A-BCMSs-SO_(3)H@PTFE fibers.The results of catalytic reaction kinetics showed that the yield of 5-ethoxymethylfurfural can reach more than 60%after 72 h of acid-catalyzed reaction.The stability test showed that the as-prepared A-BCMSs-SO_(3)H@PTFE fibers still maintained a stable acid catalytic activity after four recycles.展开更多
A series of biobased heterogeneous solid Br?nsted acid catalysts with perfect spherical microstructures are successfully fabricated directly from waste Camellia oleifera shells by a simple hydrothermal carbonization-a...A series of biobased heterogeneous solid Br?nsted acid catalysts with perfect spherical microstructures are successfully fabricated directly from waste Camellia oleifera shells by a simple hydrothermal carbonization-annealing-sulfonation process. 350℃ low temperature annealing process helps to increase the activity of the catalyst due to the simultaneous maintenance of the spherical microstructure and aromatic carbon framework. As a renewable catalyst with low cost, the as-prepared materials are successfully applied on the synthesis of green renewable liquid biofuel 5-ethoxymethylfurfural(EMF) directly from fructose. In the catalytic test, the influences of reaction time and temperature, fructose concentration, and adding amount of the catalyst on the yield of EMF are investigated systematically. As a result, the optimal reaction temperature is 100℃, the EMF yield monotonically increases with prolonging the reaction time from 3 to 24 h, the optimal fructose concentration is0.5 mmol, and the EMF yield gradually increases with increasing the adding amount of the catalyst from 50 to 150 mg. In addition, the asprepared catalysts exhibit considerably high stability in the current EMF synthesis system, and they can maintain a similar level of reactivity after four catalytic cycles.展开更多
Photocatalytic selective transform native lignin into valuable chemicals is an attractive but challenging task.Herein,we report a mesoporous sulfur-doped carbon nitride(MSCN-0.5)which is prepared by a facile one-step ...Photocatalytic selective transform native lignin into valuable chemicals is an attractive but challenging task.Herein,we report a mesoporous sulfur-doped carbon nitride(MSCN-0.5)which is prepared by a facile one-step thermal condensation strategy.It is highly active and selective for the cleavage Cα-Cβbond inβ-O-4 lignin model compound under visible light radiation at room temperature,achieving 99%substrate conversion and 98%Cα-Cβbond cleavage selectivity.Mechanistic studies revealed that the Cβ-H bond of lignin model compounds activated by holes and generate key Cβradical intermediates,further induced the Cα-Cβbond cleavage by superoxide anion radicals(·O2-)to produce aromatic oxygenates.Waste Camellia oleifera shell(WCOS)was taken as a representative to further understand the reaction mechanisms on native lignin.33.2 mg of monophenolic compounds(Vanillin accounted for 22%and Syringaldehyde for 34%)can be obtained by each gram of WCOS lignin,which is 2.5 times as that of the pristine carbon nitride.The present work offers useful guidance for designing metal-free heterogeneous photocatalysts for Cα-Cβbond cleavage to harvest monophenolic compounds.展开更多
Devising a desirable adsorbent for efficiently selective capture of Ag(Ⅰ) from wastewater has attracted much attention but faced with huge challenges. Herein, a novel linear o-phenanthroline-based polymer L-PRL was p...Devising a desirable adsorbent for efficiently selective capture of Ag(Ⅰ) from wastewater has attracted much attention but faced with huge challenges. Herein, a novel linear o-phenanthroline-based polymer L-PRL was prepared via chemical oxidative polymerization for the adsorption of Ag(Ⅰ). The maximum adsorption capacity for Ag(Ⅰ) by L-PRL is 325.8 mg/g at pH 0. In addition, L-PRL owes ascendant selectivity for Ag(Ⅰ) from aqueous solutions containing various interfering metal ions of Pb(Ⅱ), Co(Ⅱ), Ni(Ⅱ), Cd(Ⅱ)and Fe(Ⅲ). Multiple characterizations of FT-IR and XPS uncover that the N groups on L-PRL act as adsorption sites to coordinate with Ag(Ⅰ). Density functional theory(DFT) calculations further evidence the mechanism that L-PRL is provided with the admirable adsorptivity and selectivity for Ag(Ⅰ). It is mainly attributed to the most stable complexes of L-PRL with Ag(Ⅰ), which possesses shortest Ag-N bond length compared with other heavy metal ions. Furthermore, 93.5% of initial adsorption capacity is reserved after four continuous regeneration cycles, indicating that L-PRL is equipped with superior recyclability and durability, and L-PRL is capable of removing Ag(Ⅰ) in low-concentration actual Ag(Ⅰ)-containing wastewater completely. This study shed light on the rational design of polymer adsorbents and in-depth insight into selective removal of aqueous Ag(Ⅰ).展开更多
The selective capture of copper from strongly acidic solutions is of vital importance from the perspective of sustainable development and environmental protection.Metal organic frameworks(MOFs)have attracted the inter...The selective capture of copper from strongly acidic solutions is of vital importance from the perspective of sustainable development and environmental protection.Metal organic frameworks(MOFs)have attracted the interest of many scholars for adsorption due to their fascinating physicochemical characteristics,including adjustable structure,strong stability and porosity.Herein,pz-UiO-66 containing a pyrazine structure is successfully synthesized for the efficient separation of copper from strongly acidic conditions.Selective copper removal at low pH values is accomplished by using this material that is not available in previously reported metal–organic frameworks.Furthermore,the material exhibits excellent adsorption capacity,with a theoretical maximum copper uptake of 247 mg/g.As proven by XPS and FT-IR analysis,the coordination of pyrazine nitrogen atoms with copper ions is the dominant adsorption mechanism of copper by pz-UiO-66.This work provides an opportunity for efficient and selective copper removal under strongly acidic conditions,and promises extensive application prospects for the removal of copper in the treatment for acid metallurgical wastewater.展开更多
Quantum dots(QDs)based heterojunction is a candidate for the photocatalytic CO_(2)reduction,owing to the large extinction coefficient and easy modification of band structures.However,the van der Waals interaction caus...Quantum dots(QDs)based heterojunction is a candidate for the photocatalytic CO_(2)reduction,owing to the large extinction coefficient and easy modification of band structures.However,the van der Waals interaction causes the large charge resistance and strong recombination centers between QDs and host materials,which makes the poor photocatalytic performance.Herein,a covalent bonded CdSeTeQDs and NH_(2)-UiO-66 heterojunction(NUC-x)is constructed through an acylamino(-CONH-).The results indicate that the acylamino between NH_(2)-UiO-66 and Cd Se Te QDs can serve as the transfer channels for the photogenerated charges and stabilize the QDs.The optimized NUC-1200 achieved a CO generation rate of 228.68μmol/g,which is 13 and 4 times higher than that of NH_(2)-UiO-66 and Cd Se Te QDs,respectively.This work provides a new avenue for efficient and stable photocatalysis of QDs.展开更多
A novel defluorinative ring-opening of gem-difluorocyclopropenes is presented,providing a concise and efficient method for accessing 2-fluoropropenals and 2-fluorobuta-1,3-dienes in moderate to good yields with excell...A novel defluorinative ring-opening of gem-difluorocyclopropenes is presented,providing a concise and efficient method for accessing 2-fluoropropenals and 2-fluorobuta-1,3-dienes in moderate to good yields with excellent regio-and stereoselectivities.The reaction is performed under mild conditions with no need of using an excess amount of nucleophilic reagents.Water plays a crucial role in this transformation.展开更多
Rational modification by functional groups was regarded as one of efficient methods to improve the photocatalytic performance of graphitic carbon nitride(g-C3 N4).Herein,g-C3 N4 with yellow(Y-GCN)and brown(C-GCN)were ...Rational modification by functional groups was regarded as one of efficient methods to improve the photocatalytic performance of graphitic carbon nitride(g-C3 N4).Herein,g-C3 N4 with yellow(Y-GCN)and brown(C-GCN)were prepared by using the fresh urea and the urea kept for five years,respectively,for the first time.Experimental results show that the H2 production rate of the C-GCN is 39.06μmol/h,which is about 5 times of the Y-GCN.Meantime,in terms of apparent quantum efficiency(AQ.E)at 420 nm,C-GCN has a value of 6.3%and nearly 7.3 times higher than that of Y-GCN(0.86%).The results of XRD,IR,DRS,and NMR show,different from Y-GCN,a new kind of functional group of—N=CH—was firstly in-situ introduced into the C-GCN,resulting in good visible light absorption,and then markedly improving the photocatalytic performance.DFT calculation also confirms the effect of the—N=CH—group band structure of g-C3N4.Furthermore,XPS results demonstrate that the existence of—N=CH—groups in C-GCN results in tight interaction between C-GCN and Pt nanoparticles,and then improves the charge separation and photocatalytic performance.The present work demonstrates a good example of"defect engineering"to modify the intrinsic molecular structure of g-C3N4 and provides a new avenue to enhance the photocatalytic activity of g-C3N4 via facile and environmental-friendly method.展开更多
Constructing heterojunction between two semiconductors with matched energy band structure is an effective modification method to obtain excellent photocatalysts.The experimental scheme adopts a simple solvent method t...Constructing heterojunction between two semiconductors with matched energy band structure is an effective modification method to obtain excellent photocatalysts.The experimental scheme adopts a simple solvent method to self-assemble nitrogen doped carbon dots(N-CDs)on the surface of sulfur doped carbon nitride(S-C_(3)N_(4))semiconductor throughπ-πconjugate interaction.Based on this,a novel 0D/2D S-scheme heterojunction N-CDs/S-C_(3)N_(4)hybrid was successfully prepared.The degradation kinetic constants of N-CDs/S-C_(3)N_(4)for rhodamine B(RhB)and p-nitrophenol(PNP)reached 0.23522 and 0.01342 min^(−1),repectively,which were 2.72 and 2.65 times that of S-C_(3)N_(4).The highest photocatalytic hydrogen evolution rate was observed under the simulated sunlight irradiation,which was 2.30 times that of S-C_(3)N_(4).The improvement of photocatalytic performance was mainly based on the formation of the S-scheme heterojunction between S-C_(3)N_(4)and N-CDs.The effects of internal electric field,π-πconjugate interaction and band bending promoted the photogenerated h^(+)and e^(−) with low redox ability to recombine and retained the beneficial h+and e−with strong redox ability,which contributed to the production of more active species of h^(+) and•O_(2)−,therefore the photocatalytic degradation and hydrogen evolution performance were significantly enhanced.展开更多
As promising approaches in wastewater treatment, advanced oxidation processes(AOPs) can efficiently degrade and mineralize the organic wastes and contaminants by generating reactive radicals like ·OH, ·SO_(4...As promising approaches in wastewater treatment, advanced oxidation processes(AOPs) can efficiently degrade and mineralize the organic wastes and contaminants by generating reactive radicals like ·OH, ·SO_(4)^(-), and ·O_(2)^(-). However, due to the stronger oxidability, these reactive radicals exhibit lower selectivity of degradation.展开更多
Donor-acceptor(D-A)conjugated polymers are widely used in photovoltaic applications and heteroge-neous catalysis due to their tunable building block and pre-designable structures.Here,a series of ad-justable Donor-acc...Donor-acceptor(D-A)conjugated polymers are widely used in photovoltaic applications and heteroge-neous catalysis due to their tunable building block and pre-designable structures.Here,a series of ad-justable Donor-acceptor(D-A)benzothiodiazole-based conjugated polymers were designed and synthe-sized.The photocatalytic performance could be improved by fine-tuning the chemical structure by halo-gen substitution(F or Cl).The polymers exhibited excellent optoelectronic properties and were effective photocatalysts for the degradation of RhB and MO dyes,as well as promoting the oxidative coupling of benzylamines.Complete degradation of RhB and MO occurred in 30 min under visible light radiation,while the yield of benzylamine coupling mediated by superoxide anion was as high as 82%.Systematic characterization methods were used to gain insights on the unique photocatalytic performance of the polymers.Our findings provide further insights into the design and synthesis of benzothiadiazole-based conjugated polymers as promising organic photocatalysts for solar energy conversion.展开更多
A new palladium-catalyzed oxidative conversion of N-arylpropiolamides and H2O to various indoline-2,3-diones and acids through the C≡C triple bond cleavage and C(sp2)–H functionalization is described,which is promot...A new palladium-catalyzed oxidative conversion of N-arylpropiolamides and H2O to various indoline-2,3-diones and acids through the C≡C triple bond cleavage and C(sp2)–H functionalization is described,which is promoted by a cooperative action of catalytic CuBr2,2,2,6,6-tetramethyl-1-piperidinyloxy(TEMPO)and O2.The method provides a practical tool for transformations of alkynes by means of a C–H functionalization strategy,which enables the formation of one C–C bond and multiple C–O bonds in a single reaction with high substrates compatibility and excellent functional group tolerance.展开更多
The massive conversion of resourceful biomass to carbon nanomaterials not only opens a new avenue to effective and economical disposal of biomass,but provides a possibility to produce highly valued functionalized carb...The massive conversion of resourceful biomass to carbon nanomaterials not only opens a new avenue to effective and economical disposal of biomass,but provides a possibility to produce highly valued functionalized carbon-based electrodes for energy storage and conversion systems.In this work,biomass is applied to a facile and scalable one-step pyrolysis method to prepare three-dimensional(3D)carbon nanotubes/mesoporous carbon architecture,which uses transition metal inorganic salts and melamine as initial precursors.The role of each employed component is investigated,and the electrochemical performance of the attained product is explored.Each component and precise regulation of their dosage is proven to be the key to successful conversion of biomass to the desired carbon nanomaterials.Owing to the unique 3D architecture and integration of individual merits of carbon nanotubes and mesoporous carbon,the as-synthesized carbon nanotubes/mesoporous carbon hybrid exhibits versatile application toward lithium-ion batteries and Zn-air batteries.Apparently,a significant guidance on effective conversion of biomass to functionalized carbon nanomaterials can be shown by this work.展开更多
A rhodium-catalyzed[4+3]cycloaddition reaction between N-methoxybenzamides and gem–difluorocyclopropenes is described.The reaction offers a mild and efficient approach towards the synthesis of fluorinated 2 H-azepin-...A rhodium-catalyzed[4+3]cycloaddition reaction between N-methoxybenzamides and gem–difluorocyclopropenes is described.The reaction offers a mild and efficient approach towards the synthesis of fluorinated 2 H-azepin-2-ones with broad substrate scope.A consecutive HOAc-assisted C–N bond formation and fluorine elimination are involved as key steps for success as illustrated by detailed DFT studies.展开更多
基金supported by the National Natural Science Foundation of China(52263017,21965023,52173170,51973087,and22065025)the Science Fund for Distinguished Young Scholars of Jiangxi Province(20212ACB214009)+2 种基金the Natural Science Foundation of Jiangxi Province(20212ACB203010,20224BAB214007 and20212BAB204052)the Training Project of High-level and Highskilled Leading Talents of Jiangxi Province(2023)the Thousand Talents Plan of Jiangxi Province(jxsq2019201004 and jxsq2020101068)。
文摘Organic solar cells(OSCs)have gained conspicuous progress during the past few decades due to the development of materials and upgrading of the device structure.The power conversion efficiency(PCE)of the single-junction device had surpassed 19%.The cathode interface layer(CIL),by optimizing the connection between the active layer and the cathode electrode,has become a momentous part to strengthen the performances of the OSCs.Simultaneously,CIL is also indispensable to illustrating the working mechanism of OSCs and enhancing the stability of the OSCs.In this essay,hybrid CILs in OSCs have been summarized.Firstly,the advancement and operating mechanism of OSCs,and the effects and relevant design rules of CIL are briefly concluded;secondly,the significant influence of CIL on enhancing the stability and PCE of OSCs is presented;thirdly,the characteristics of organic hybrid CIL and organic-inorganic hybrid CIL are introduced.Finally,the conclusion and outlook of CIL are summarized.
基金the National Natural Science Foundation of China(22265021)the Aeronautical Science Foundation of China(2020Z056056003).
文摘Metal–organic gel(MOG)derived composites are promising multi-functional materials due to their alterable composition,identifiable chemical homogeneity,tunable shape,and porous structure.Herein,stable metal–organic hydrogels are prepared by regulating the complexation effect,solution polarity and curing speed.Meanwhile,collagen peptide is used to facilitate the fabrication of a porous aerogel with excellent physical properties as well as the homogeneous dispersion of magnetic particles during calcination.Subsequently,two kinds of heterometallic magnetic coupling systems are obtained through the application of Kirkendall effect.FeCo/nitrogen-doped carbon(NC)aerogel demonstrates an ultra-strong microwave absorption of−85 dB at an ultra-low loading of 5%.After reducing the time taken by atom shifting,a FeCo/Fe3O4/NC aerogel containing virus-shaped particles is obtained,which achieves an ultra-broad absorption of 7.44 GHz at an ultra-thin thickness of 1.59 mm due to the coupling effect offered by dual-soft-magnetic particles.Furthermore,both aerogels show excellent thermal insulation property,and their outstanding radar stealth performances in J-20 aircraft are confirmed by computer simulation technology.The formation mechanism of MOG is also discussed along with the thermal insulation and electromagnetic wave absorption mechanism of the aerogels,which will enable the development and application of novel and lightweight stealth coatings.
基金Funded by the National Natural Science Foundation of China(No.20401088)Open Fund of Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resource Recycle(No.ST201522010)
文摘The synthesis of Bi_2S_3 hierarchical nanostructure was reported by a solvothermal reaction using ethylene disulfhydrate as the sulfur source and chelating reagent. The as-synthesized samples were characterized by X-ray diffraction(XRD), Raman, X-ray photoelectron spectroscopy(XPS), scanning electron microscopy(SEM) and photoluminescence(PL). The XRD, Raman, and XPS data confirmed that the as-synthesized sample belongs to orthorhombic phase Bi_2S_3. The SEM observations displayed that Bi_2S_3 hierarchical nanostructure assembled from nanorods. A 410 nm ultraviolet photoluminescence(PL) emission of as-synthesized Bi_2S_3 was observed when the sample was excited with wavelength of 320-330 nm. The Bi_2S_3 hierarchical nanostructure also shows a significant enhancement of photocatalytic capability toward degrading methyl orange(MO) under UV light, the photodegradation of MO reaches 95% within 180 min.
基金financially supported by the National Natural Science Foundation of China(52072165,51662031 and 51720105001)the general project of science and technology research of Jiangxi Provincial Department of Education(DA202102160)+1 种基金the project funded by China Postdoctoral Science Foundation(2019M653583)the starting research fund(EA202102179)。
文摘Herein,Co_(2)P nanorods(NRs)with exposure to high-index facets(HIFs)were prepared by a special assembly-calcination method using thioacetamide(TAA)as a structure-directing reagent.The analysis of adsorption energies of S atoms on different facets as well as the surface energies of Co_(2)P indicate that the HIFs become more stable after adsorbing S atoms.With rich unsaturated sites on HIFs,the photochemical reduction rate of CO_(2)over Co_(2)P NRs is 14.5 mmol h^(-1)g^(-1)for the production of CO within 3 h.The analysis of electron transfer,bond lengths,bond angles and adsorption energies indicate that the CO_(2)molecules are more easily adsorbed and activated on the HIFs.The free energy calculations and d band theory demonstrate that the HIFs are conducive to reducing the formation energy barriers as well as improving the stability of the intermediate^(*)COOH,then enhancing the catalytic performance of CO_(2)reduction.
基金financially supported by the National Natural Science Foundation of China(Project No.21875253,No.51903235)。
文摘Electrosynthesis has recently attracted intensive research attentions and holds great potential in implementing scalable green synthesis thanks to more and more readily accessible renewable electric energy.
基金financially supported by the National Natural Science Foundation of China(Grants 52072165,52070092,51662031)。
文摘Oxygen vacancy plays vital roles in regulating the electronic and charge distribution of the oxygen deficient materials.Herein,abundant oxygen vacancies are created during assembling the two-dimensional(2D)ultra-thin Bi_(2)MoO_(6) nanoflakes into three dimensional(3D)Bi_(2)MoO_(6) nanospheres,resulting in significantly improved performance for photocatalytical conversion of CO_(2) into liquid hydrocarbons.The increased performance is contributed by two primary sites,namely the abundant oxygen vacancy and the exposed molybdenum(Mo)atom induced by oxygen-migration,as revealed by the theoretical calculation.The oxygen vacancy(Ov)and uncovered Mo atom serving as dual binding sites for trapping CO_(2) molecules render the synchronous fixation-reduction process,resulting in the decline of activation energy for CO_(2) reduction from 2.15 eV on bulk Bi_(2)MoO_(6) to 1.42 eV on Ov-rich Bi_(2)MoO_(6).Such a striking decrease in the activation energy induces the efficient selective generation of liquid hydrocarbons,especially the methanol(C_(2)H_(5) OH)and ethanol(CH_(3) OH).The yields of CH_(3) OH and C_(2)H_(5) OH over the optimal Ov-Bi_(2)MoO_(6) is high up to 106.5 and 10.3μmol g^(-1) respectively,greatly outperforming that on the Bulk-Bi_(2)MoO_(6).
基金financially supported by the National Natural Science Foundation of China(21966023,21665018)the Natural Science Foundation of Jiangxi Province,China(20171ACB21035)
文摘In this paper,sulfonic groups functionalized annealed bio-based carbon microspheres loaded polytetrafluoroethylene(A-BCMSs-SO_(3)H@PTFE)fibers with high activity,high stability,and easy regeneration were successfully fabricated by a simple method using low-cost raw materials.The characterization results showed that the annealed biomass carbon microspheres derived from waste Camellia oleifera shells were evenly distributed on the polytetrafluoroethylene fibers and the sulfonic groups can be successfully loaded on the surface of annealed biomass carbon microspheres by room temperature sulfonation.Subsequently,the as-prepared A-BCMSs-SO_(3)H@PTFE fibers were applied to the acidcatalyzed synthesis of liquid biofuel 5-ethoxymethylfurfural.The catalytic experiment results indicated that the annealing temperature and time during catalyst preparation have a significant effect on the activity and selectivity of A-BCMSs-SO_(3)H@PTFE fibers.The results of catalytic reaction kinetics showed that the yield of 5-ethoxymethylfurfural can reach more than 60%after 72 h of acid-catalyzed reaction.The stability test showed that the as-prepared A-BCMSs-SO_(3)H@PTFE fibers still maintained a stable acid catalytic activity after four recycles.
基金supported by the National Natural Science Foundation of China (51568049, 21665018, 51468043, 21366024)the Natural Science Foundation of Jiangxi Province, China (20161BAB206118, 20171ACB21035)+1 种基金Distinguished Youth Science Fund of Jiangxi Province, China (20162BCB23043)the Natural Science Foundation of Jiangxi Provincial Department of Education, China (GJJ14515)
文摘A series of biobased heterogeneous solid Br?nsted acid catalysts with perfect spherical microstructures are successfully fabricated directly from waste Camellia oleifera shells by a simple hydrothermal carbonization-annealing-sulfonation process. 350℃ low temperature annealing process helps to increase the activity of the catalyst due to the simultaneous maintenance of the spherical microstructure and aromatic carbon framework. As a renewable catalyst with low cost, the as-prepared materials are successfully applied on the synthesis of green renewable liquid biofuel 5-ethoxymethylfurfural(EMF) directly from fructose. In the catalytic test, the influences of reaction time and temperature, fructose concentration, and adding amount of the catalyst on the yield of EMF are investigated systematically. As a result, the optimal reaction temperature is 100℃, the EMF yield monotonically increases with prolonging the reaction time from 3 to 24 h, the optimal fructose concentration is0.5 mmol, and the EMF yield gradually increases with increasing the adding amount of the catalyst from 50 to 150 mg. In addition, the asprepared catalysts exhibit considerably high stability in the current EMF synthesis system, and they can maintain a similar level of reactivity after four catalytic cycles.
基金finacially supported by the National Natural Science Foundation of China(Nos.21966023,21665018 and 51568049)the Natural Science Foundation of Jiangxi Province,China(No.20171ACB21035)Jiangxi Province Graduate Student Innovation Special Fund(No.YC2020-S513)。
文摘Photocatalytic selective transform native lignin into valuable chemicals is an attractive but challenging task.Herein,we report a mesoporous sulfur-doped carbon nitride(MSCN-0.5)which is prepared by a facile one-step thermal condensation strategy.It is highly active and selective for the cleavage Cα-Cβbond inβ-O-4 lignin model compound under visible light radiation at room temperature,achieving 99%substrate conversion and 98%Cα-Cβbond cleavage selectivity.Mechanistic studies revealed that the Cβ-H bond of lignin model compounds activated by holes and generate key Cβradical intermediates,further induced the Cα-Cβbond cleavage by superoxide anion radicals(·O2-)to produce aromatic oxygenates.Waste Camellia oleifera shell(WCOS)was taken as a representative to further understand the reaction mechanisms on native lignin.33.2 mg of monophenolic compounds(Vanillin accounted for 22%and Syringaldehyde for 34%)can be obtained by each gram of WCOS lignin,which is 2.5 times as that of the pristine carbon nitride.The present work offers useful guidance for designing metal-free heterogeneous photocatalysts for Cα-Cβbond cleavage to harvest monophenolic compounds.
基金financially supported by the National Science Fund for Distinguished Young Scholars(No.52125002)the National Science Foundation of China(No.52100043)+1 种基金the National Key Research and Development Program of China(No.2019YFC1907900)the National Science Foundation of Jiangxi Province(No.20202BABL213037)。
文摘Devising a desirable adsorbent for efficiently selective capture of Ag(Ⅰ) from wastewater has attracted much attention but faced with huge challenges. Herein, a novel linear o-phenanthroline-based polymer L-PRL was prepared via chemical oxidative polymerization for the adsorption of Ag(Ⅰ). The maximum adsorption capacity for Ag(Ⅰ) by L-PRL is 325.8 mg/g at pH 0. In addition, L-PRL owes ascendant selectivity for Ag(Ⅰ) from aqueous solutions containing various interfering metal ions of Pb(Ⅱ), Co(Ⅱ), Ni(Ⅱ), Cd(Ⅱ)and Fe(Ⅲ). Multiple characterizations of FT-IR and XPS uncover that the N groups on L-PRL act as adsorption sites to coordinate with Ag(Ⅰ). Density functional theory(DFT) calculations further evidence the mechanism that L-PRL is provided with the admirable adsorptivity and selectivity for Ag(Ⅰ). It is mainly attributed to the most stable complexes of L-PRL with Ag(Ⅰ), which possesses shortest Ag-N bond length compared with other heavy metal ions. Furthermore, 93.5% of initial adsorption capacity is reserved after four continuous regeneration cycles, indicating that L-PRL is equipped with superior recyclability and durability, and L-PRL is capable of removing Ag(Ⅰ) in low-concentration actual Ag(Ⅰ)-containing wastewater completely. This study shed light on the rational design of polymer adsorbents and in-depth insight into selective removal of aqueous Ag(Ⅰ).
基金the National Natural Science Foundation of China(Nos.52125002 and 51908270)the Natural Science Foundation of Jiangxi Province(No.20212ACB213006),and the National Key Research and Development Program of China(No.2019YFC1907900).
文摘The selective capture of copper from strongly acidic solutions is of vital importance from the perspective of sustainable development and environmental protection.Metal organic frameworks(MOFs)have attracted the interest of many scholars for adsorption due to their fascinating physicochemical characteristics,including adjustable structure,strong stability and porosity.Herein,pz-UiO-66 containing a pyrazine structure is successfully synthesized for the efficient separation of copper from strongly acidic conditions.Selective copper removal at low pH values is accomplished by using this material that is not available in previously reported metal–organic frameworks.Furthermore,the material exhibits excellent adsorption capacity,with a theoretical maximum copper uptake of 247 mg/g.As proven by XPS and FT-IR analysis,the coordination of pyrazine nitrogen atoms with copper ions is the dominant adsorption mechanism of copper by pz-UiO-66.This work provides an opportunity for efficient and selective copper removal under strongly acidic conditions,and promises extensive application prospects for the removal of copper in the treatment for acid metallurgical wastewater.
基金the financial support of the National Natural Science Foundation of China(Nos.52100186 and 52170082)the Natural Science Foundation of Jiangxi Province(No.20212ACB203008)。
文摘Quantum dots(QDs)based heterojunction is a candidate for the photocatalytic CO_(2)reduction,owing to the large extinction coefficient and easy modification of band structures.However,the van der Waals interaction causes the large charge resistance and strong recombination centers between QDs and host materials,which makes the poor photocatalytic performance.Herein,a covalent bonded CdSeTeQDs and NH_(2)-UiO-66 heterojunction(NUC-x)is constructed through an acylamino(-CONH-).The results indicate that the acylamino between NH_(2)-UiO-66 and Cd Se Te QDs can serve as the transfer channels for the photogenerated charges and stabilize the QDs.The optimized NUC-1200 achieved a CO generation rate of 228.68μmol/g,which is 13 and 4 times higher than that of NH_(2)-UiO-66 and Cd Se Te QDs,respectively.This work provides a new avenue for efficient and stable photocatalysis of QDs.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21861007 and 21702034)Natural Science Foundation of Guangxi Province(Nos.2021GXNSFAA075024 and 2022GXNSFAA035468)+2 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2020A1515010624)Natural Science Foundation of Jiangxi Province of China(No.20212BAB213024)“BAGUI Scholar”Program of Guangxi Province of China.
文摘A novel defluorinative ring-opening of gem-difluorocyclopropenes is presented,providing a concise and efficient method for accessing 2-fluoropropenals and 2-fluorobuta-1,3-dienes in moderate to good yields with excellent regio-and stereoselectivities.The reaction is performed under mild conditions with no need of using an excess amount of nucleophilic reagents.Water plays a crucial role in this transformation.
基金financial support of the National Natural Science Foundation of China(NSFC,Nos.51622806,51878325,51868050,51378246 and 51720105001)the Natural Science Foundation of Jiangxi Province(Nos.20162BCB22017,20165BCB18008,20171ACB20017,20133ACB21001 and 20171BAB206049)。
文摘Rational modification by functional groups was regarded as one of efficient methods to improve the photocatalytic performance of graphitic carbon nitride(g-C3 N4).Herein,g-C3 N4 with yellow(Y-GCN)and brown(C-GCN)were prepared by using the fresh urea and the urea kept for five years,respectively,for the first time.Experimental results show that the H2 production rate of the C-GCN is 39.06μmol/h,which is about 5 times of the Y-GCN.Meantime,in terms of apparent quantum efficiency(AQ.E)at 420 nm,C-GCN has a value of 6.3%and nearly 7.3 times higher than that of Y-GCN(0.86%).The results of XRD,IR,DRS,and NMR show,different from Y-GCN,a new kind of functional group of—N=CH—was firstly in-situ introduced into the C-GCN,resulting in good visible light absorption,and then markedly improving the photocatalytic performance.DFT calculation also confirms the effect of the—N=CH—group band structure of g-C3N4.Furthermore,XPS results demonstrate that the existence of—N=CH—groups in C-GCN results in tight interaction between C-GCN and Pt nanoparticles,and then improves the charge separation and photocatalytic performance.The present work demonstrates a good example of"defect engineering"to modify the intrinsic molecular structure of g-C3N4 and provides a new avenue to enhance the photocatalytic activity of g-C3N4 via facile and environmental-friendly method.
基金support from the National Natural Science Foundation of China (Nos. 51962023, 51772139)the Natural Science Foundation of Jiangxi Province, China (No. 20192ACBL21047, 20212BAB204045)+1 种基金the Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle (Nanchang Hangkong University) (No. ES202002077)the 2019 Project of Liaoning Education Department (No. 2019LNJC20)
文摘Constructing heterojunction between two semiconductors with matched energy band structure is an effective modification method to obtain excellent photocatalysts.The experimental scheme adopts a simple solvent method to self-assemble nitrogen doped carbon dots(N-CDs)on the surface of sulfur doped carbon nitride(S-C_(3)N_(4))semiconductor throughπ-πconjugate interaction.Based on this,a novel 0D/2D S-scheme heterojunction N-CDs/S-C_(3)N_(4)hybrid was successfully prepared.The degradation kinetic constants of N-CDs/S-C_(3)N_(4)for rhodamine B(RhB)and p-nitrophenol(PNP)reached 0.23522 and 0.01342 min^(−1),repectively,which were 2.72 and 2.65 times that of S-C_(3)N_(4).The highest photocatalytic hydrogen evolution rate was observed under the simulated sunlight irradiation,which was 2.30 times that of S-C_(3)N_(4).The improvement of photocatalytic performance was mainly based on the formation of the S-scheme heterojunction between S-C_(3)N_(4)and N-CDs.The effects of internal electric field,π-πconjugate interaction and band bending promoted the photogenerated h^(+)and e^(−) with low redox ability to recombine and retained the beneficial h+and e−with strong redox ability,which contributed to the production of more active species of h^(+) and•O_(2)−,therefore the photocatalytic degradation and hydrogen evolution performance were significantly enhanced.
文摘As promising approaches in wastewater treatment, advanced oxidation processes(AOPs) can efficiently degrade and mineralize the organic wastes and contaminants by generating reactive radicals like ·OH, ·SO_(4)^(-), and ·O_(2)^(-). However, due to the stronger oxidability, these reactive radicals exhibit lower selectivity of degradation.
基金financially supported by National Natural Science Foundation of China(No.52173099)the Science and Technology Department of Jiangxi Province(No.20192BBEL50025)+1 种基金Nanchang Hangkong University(No.EA201902288)the Special Fund for Graduate Innovation(No.YC2020-011).
文摘Donor-acceptor(D-A)conjugated polymers are widely used in photovoltaic applications and heteroge-neous catalysis due to their tunable building block and pre-designable structures.Here,a series of ad-justable Donor-acceptor(D-A)benzothiodiazole-based conjugated polymers were designed and synthe-sized.The photocatalytic performance could be improved by fine-tuning the chemical structure by halo-gen substitution(F or Cl).The polymers exhibited excellent optoelectronic properties and were effective photocatalysts for the degradation of RhB and MO dyes,as well as promoting the oxidative coupling of benzylamines.Complete degradation of RhB and MO occurred in 30 min under visible light radiation,while the yield of benzylamine coupling mediated by superoxide anion was as high as 82%.Systematic characterization methods were used to gain insights on the unique photocatalytic performance of the polymers.Our findings provide further insights into the design and synthesis of benzothiadiazole-based conjugated polymers as promising organic photocatalysts for solar energy conversion.
基金supported by the National Natural Science Foundation of China(21625203,21871126)the Opening Fund of KLCBTCMR,Ministry of Education(KLCBTCMR18-02)
文摘A new palladium-catalyzed oxidative conversion of N-arylpropiolamides and H2O to various indoline-2,3-diones and acids through the C≡C triple bond cleavage and C(sp2)–H functionalization is described,which is promoted by a cooperative action of catalytic CuBr2,2,2,6,6-tetramethyl-1-piperidinyloxy(TEMPO)and O2.The method provides a practical tool for transformations of alkynes by means of a C–H functionalization strategy,which enables the formation of one C–C bond and multiple C–O bonds in a single reaction with high substrates compatibility and excellent functional group tolerance.
基金financially supported by the National Key Research and Development Program of China(Grant No.2019YFC1907900)Science&Technology Talents Lifting Project of Hunan Province(Grant No.2022TJ-N16)the Scientific Research Fund of Hunan Provincial Education Department,China(Grant No.21A0392).
文摘The massive conversion of resourceful biomass to carbon nanomaterials not only opens a new avenue to effective and economical disposal of biomass,but provides a possibility to produce highly valued functionalized carbon-based electrodes for energy storage and conversion systems.In this work,biomass is applied to a facile and scalable one-step pyrolysis method to prepare three-dimensional(3D)carbon nanotubes/mesoporous carbon architecture,which uses transition metal inorganic salts and melamine as initial precursors.The role of each employed component is investigated,and the electrochemical performance of the attained product is explored.Each component and precise regulation of their dosage is proven to be the key to successful conversion of biomass to the desired carbon nanomaterials.Owing to the unique 3D architecture and integration of individual merits of carbon nanotubes and mesoporous carbon,the as-synthesized carbon nanotubes/mesoporous carbon hybrid exhibits versatile application toward lithium-ion batteries and Zn-air batteries.Apparently,a significant guidance on effective conversion of biomass to functionalized carbon nanomaterials can be shown by this work.
基金National Natural Science Foundation of China(Nos.21861007,21702034)Natural Science Foundation of Guangxi Province(No.2021GXNSFAA075024)+1 种基金“BAGUI Scholar”Program of Guangxi Province of ChinaHigh-Level Innovation Team and Distinguished Scholar Program in Guangxi Colleges and Universities。
文摘A rhodium-catalyzed[4+3]cycloaddition reaction between N-methoxybenzamides and gem–difluorocyclopropenes is described.The reaction offers a mild and efficient approach towards the synthesis of fluorinated 2 H-azepin-2-ones with broad substrate scope.A consecutive HOAc-assisted C–N bond formation and fluorine elimination are involved as key steps for success as illustrated by detailed DFT studies.
