La_(2)O_(3)/Bi_(2)O_(3)photocatalysts were prepared by impregnation of Bi_(2)O_(3)with an aqueous solution of lanthanum precursor followed by calcination at different temperatures.The composite materials were used for...La_(2)O_(3)/Bi_(2)O_(3)photocatalysts were prepared by impregnation of Bi_(2)O_(3)with an aqueous solution of lanthanum precursor followed by calcination at different temperatures.The composite materials were used for the first time for the photocatalytic removal of Hg~0 from a simulated flue gas under UV light irradiation.The results showed that the sample containing 6 wt.%La_(2)O_(3)and calcined at 500°C has the highest dispersion of the active sites,which was promoted by the strong interaction with the support(i.e.,the formation of Bi-O-La species).Since they are fully accessible on the surface,the material also exhibits excellent optical properties while the heterojunction formed in La_(2)O_(3)/Bi_(2)O_(3)promotes the separation and migration of photoelectron-hole pairs and thus Hg~0 oxidation efficiency is enhanced.The effects of the various factors(e.g.,the reaction temperature and composition of the simulated flue gas(i.e.,O_(2),NO,H_(2)O,and SO_(2)))on the efficiency of the Hg~0 photocatalytic oxidation were investigated.The results demonstrated that O_(2)and SO_(2)enhanced the efficiency of the reaction while the reaction temperature,NO,and H_(2)O had an inhibitory effect.展开更多
TiO_(2) supported on active carbon fiber(TiO_(2)/ACF),an absorbable photocatalyst,is a new kind of material applied in air purification.In this paper,the influence of environmental temperature(T)and relative humidity(...TiO_(2) supported on active carbon fiber(TiO_(2)/ACF),an absorbable photocatalyst,is a new kind of material applied in air purification.In this paper,the influence of environmental temperature(T)and relative humidity(RH)on the gas-solid adsorption of toluene and the photocatalytic oxidation(PCO)efficiency of adsorbed toluene on TiO_(2)/ACF were studied,and then,the purification capability of TiO_(2)/ACF was estimated.PCO results showed that although the PCO efficiency increased under high RH and T levels,the amount of adsorption of toluene decreased.Moreover,quantitative analysis results of intermediates indicated that more environmental risk emerged when PCO of toluene was carried out at higher environmental T and RH levels because more toxic intermediates would be accumulated on the TiO_(2)/ACF.So,it is significant to control the environmental T and RH conditions in the application of the PCO technique.T 525uC and RH530% is the optimal condition for purifying toluene in our experimental system.展开更多
Self-assembled supramolecular structures with efficient singlet oxygen(1O2)-generation ability are expected to enable photocatalytic oxidation reactions.Herein,we use two photosensitizers,perylene diimide and benzothi...Self-assembled supramolecular structures with efficient singlet oxygen(1O2)-generation ability are expected to enable photocatalytic oxidation reactions.Herein,we use two photosensitizers,perylene diimide and benzothiadiazole derivative,as the boards to prepare two barrel-shaped metallacages viametal-coordination-driven self-assembly.展开更多
Lignocellulose shows significantly potential in sustainable conversion to high-quality fuel and valueadded chemicals with the demands for realizing the rapid cycle of carbon resources and helping to reach carbon neutr...Lignocellulose shows significantly potential in sustainable conversion to high-quality fuel and valueadded chemicals with the demands for realizing the rapid cycle of carbon resources and helping to reach carbon neutrality in nature.Selective tailoring of α-O-4,β-O-4,etc.linkages in lignin has always been viewed as "death blow" for its depolymerization.Herein,novel sodium lignosulfonate(SL) modified Fe_(3)O_(4)/TiO_(2)(SL-Fe_(3)O_(4)/TiO_(2)) spherical particles have been developed and used as catalysts for selectively photocatalytic oxidative cleavage of organosolv lignin.As expected,80% selective conversion of lignin in C2-C4 esters has been achieved,while C-O bonds in lignin model compounds can be effectively cleaved.Other than normal hydroxyl radical-mediated photocatalytic depolymerization of lignin over TiO_(2)-based materials,in this contribution,mechanism studies indicate that photogenerated holes and superoxide anion radicals are main active species,which trigger the cleavage of α/β-O-4 bond,and the isotopelabeling study confirms the crucial factor of C_β-H dehydrogenation in cleavage of β-O-4 bonds.展开更多
The synthesis of oxygen vacancies(OVs)-modified TiO_(2)under mild conditions is attractive.In this work,OVs were easily introduced in TiO_(2)lattice during the hydrothermal doping process of trivalent iron ions.Theore...The synthesis of oxygen vacancies(OVs)-modified TiO_(2)under mild conditions is attractive.In this work,OVs were easily introduced in TiO_(2)lattice during the hydrothermal doping process of trivalent iron ions.Theoretical calculations based on a novel charge-compensation structure model were employed with experimental methods to reveal the intrinsic photocatalytic mechanism of Fe-doped TiO_(2)(Fe-TiO_(2)).The OVs formation energy in Fe-TiO_(2)(1.12 eV)was only 23.6%of that in TiO_(2)(4.74 eV),explaining why Fe^(3+)doping could introduce OVs in the TiO_(2)lattice.The calculation results also indicated that impurity states introduced by Fe^(3+)and OVs enhanced the light absorption activity of TiO_(2).Additionally,charge carrier transport was investigated through the carrier lifetime and relative mass.The carrier lifetime of Fe-TiO_(2)(4.00,4.10,and 3.34 ns for 1at%,2at%,and 3at%doping contents,respectively)was longer than that of undoped TiO_(2)(3.22 ns),indicating that Fe^(3+) and OVs could promote charge carrier separation,which can be attributed to the larger relative effective mass of electrons and holes.Herein,Fe-TiO_(2)has higher photocatalytic indoor NO removal activity compared with other photocatalysts because it has strong light absorption activity and high carrier separation efficiency.展开更多
The efficiency of photocatalytic overall water splitting was mainly limited by the slow reaction kinetics of water oxidation.How to design effective surface active site to overcome the slow water oxidation reaction wa...The efficiency of photocatalytic overall water splitting was mainly limited by the slow reaction kinetics of water oxidation.How to design effective surface active site to overcome the slow water oxidation reaction was a major challenge.Here,we propose a strategy to accelerate surface water oxidation through the fabrication spatially separated double active sites.FeCoPi/Bi_(4)NbO_(8)Cl-OVs photocatalyst with spatially separated double active site was prepared by hydrogen reduction photoanode deposition method.Due to the high matching of the spatial loading positions of FeCoPi and OVs with the photogenerated charge distribution of Bi_(4)NbO_(8)Cl and corresponding reaction mechanisms of substrate,the FeCoPi and OVs on the(001)and(010)crystal planes of Bi_(4)NbO_(8)Cl photocatalyst provided surface active site for water oxidation reaction and electron shuttle reaction(Fe^(3+)/Fe^(2+)),respectively.Under visible light irradiation,the evolution O_(2)rate of FeCoPi/Bi_(4)NbO_(8)Cl OVs was 16.8μmol h^(-1),as 32.9 times as Bi_(4)NbO_(8)Cl.Furthermore,a hydrogen evolution co-catalyst PtRu@Cr_(2)O_(3)was prepared by sequential photodeposition method.Due to the introduction of Ru,the Schottky barrier between PbTiO_(3)and Pt was effectively reduced,which promoted the transfer of photogenerated electrons to PtRu@Cr_(2)O_(3)thermodynamically,the evolution H_(2)rate on PtRu@Cr_(2)O_(3)/PbTiO_(3)increased to 664.8 times.On based of the synchronous enhancement of the water oxidation performance on FeCoPi/Bi_(4)NbO_(8)Cl-OVs and water reduction performance on PtRu@Cr_(2)O_(3)/PbTiO_(3),a novel Z-Scheme photocatalytic overall water splitting system(FeCoPi/Bi_(4)NbO_(8)Cl-OVs)mediated by Fe^(3+)/Fe^(2+)had successfully constructed.Under visible light irradiation,the evolution rates of H_(2)and O_(2)were 2.5 and 1.3μmol h^(-1),respectively.This work can provide some reference for the design of active site and the controllable synthesis of OVs spatial position.On the other hand,the hydrogen evolution co catalyst(PtRu@Cr_(2)O_(3))and the co catalyst FeCoPi for oxygen evolution contributed to the construction of an overall water splitting system.展开更多
This research focuses on the evaluation of diverse approaches for removing formaldehyde from indoor environments,which is a significant concern for indoor air quality.The study systematically examines physical,chemica...This research focuses on the evaluation of diverse approaches for removing formaldehyde from indoor environments,which is a significant concern for indoor air quality.The study systematically examines physical,chemical,and biological methods to ascertain their effectiveness in formaldehyde mitigation.Physical methods,including air circulation and adsorption,particularly with activated carbon and molecular sieves,are assessed for their efficiency in various concentration scenarios.Chemical methods,such as photocatalytic oxidation using titanium dioxide and plasma technology,are analyzed for their ability to decompose formaldehyde into non-toxic substances.Additionally,biological methods involving plant purification and microbial transformation are explored for their eco-friendly and sustainable removal capabilities.The paper concludes that while each method has its merits,a combined approach may offer the most effective solution for reducing indoor formaldehyde levels.The study underscores the need for further research to integrate these methods in a practical,cost-effective,and environmentally sustainable manner,highlighting their potential to improve indoor air quality significantly.展开更多
Photocatalytic aerobic oxidation reactions are largely governed by the efficiency of charge separation and subsequent reactive oxygen species(ROS) generation. Herein, we report a polarization engineering strategy to p...Photocatalytic aerobic oxidation reactions are largely governed by the efficiency of charge separation and subsequent reactive oxygen species(ROS) generation. Herein, we report a polarization engineering strategy to promote the charge separation and ROS generation efficiency by substituting the benzene unit with furan/thiophene in porous organic polymers(POPs). Benefiting from the extent of local polarization, the thiophene-containing POP(JNU-218) exhibits the best photocatalytic performance in aerobic oxidation reactions, with a yield much higher than those for the furan-containing POP(JNU-217) and the benzenecontaining POP(JNU-216). Experimental studies and theoretical calculations reveal that the increase of local polarization can indeed reduce the exciton binding energy, and therefore facilitate the separation of electron-hole pairs. This work demonstrates a viable strategy to tune charge separation and ROS generation efficiency by modulating the dipole moments of the building blocks in porous polymeric organic semiconductors.展开更多
In the present work, the hybrid catalyst films of TiO2/CuO containing up to 10% in mol of copper were deposited onto glass surface. Precursor solutions were obtained by citrate precursor method. Films were porous and ...In the present work, the hybrid catalyst films of TiO2/CuO containing up to 10% in mol of copper were deposited onto glass surface. Precursor solutions were obtained by citrate precursor method. Films were porous and the average particle size was 20 nm determined by FEG-SEM analysis. The photocatalytic activities of these films were studied using Rhodamine B as a target compound in a fixed bed reactor developed in our laboratory and UV lamp. It was observed that the addition of copper to TiO2 increased significantly its photocatalytic activity during the oxidation of Rhodamine B. The degradation exceeded 90% within 48 hours of irradiation compared to 38% when pure TiO2 was used. Moreover, there was a reduction in the particles band gap energy when compared to that of pure TiO2. These results indicate that the TiO2/CuO films are promising catalysts for the development of fixed bed reactors to be used to treat effluents containing azo dyes.展开更多
Partial oxidation of methane into primary oxidation products with high value remains a challenge.In this work,photocatalytic oxidation of methane(CH_(4))with high methyl hydroperoxide(CH_(3)OOH)selectivity is achieved...Partial oxidation of methane into primary oxidation products with high value remains a challenge.In this work,photocatalytic oxidation of methane(CH_(4))with high methyl hydroperoxide(CH_(3)OOH)selectivity is achieved using pure titanium oxide(TiO_(2))without any cocatalyst at room temperature and atmospheric pressure.The CH_(3)OOH production rate can reach up to 2050±88μmol·g^(-1)·h^(-1) at pH≈7.0 with 100%selectivity in the liquid product.The stable reaction cycle can reach more than 30 times.This low-cost system achieves superior CH_(4) conversion activity and selectivity compared with similar work.The energy of hydrogen peroxide(H_(2)O_(2))to adsorbed hydroperoxyl radical(^(*)OOH)has a significantly lower reaction energy than conversion to adsorbed hydroxyl radical(*OH)on the(210)surface of the TiO_(2).The^(*)OOH preferentially combines with methyl radical(·CH_(3))to form the most energetically favorable CH_(3)OOH.The mild oxidative environment of this system prevents the reduction of CH_(3)OOH to CH_(3)OH or over-oxidation of CH_(4),which ensures the final CH_(3)OOH with high selectivity and stability.This work provided a low-cost but highly efficient method to achieve partial oxidation with superior selectivity,i.e.,to convert CH_(4) into high-value chemicals.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
This work reported the lanthanide ion(Gd^(3+))doped tungsten trioxide(Gd-WO_(3))nanocrystal for remarkable promoted photocatalytic degradation of organic pollutants and simultaneous in-situ H_(2)O_(2)production.With d...This work reported the lanthanide ion(Gd^(3+))doped tungsten trioxide(Gd-WO_(3))nanocrystal for remarkable promoted photocatalytic degradation of organic pollutants and simultaneous in-situ H_(2)O_(2)production.With doped lanthanide ion(Gd^(3+)),Gd-WO_(3)showed a much broad and enhanced solar light absorption,which not only promoted the photocatalytic degradation efficiency of organic compounds,but also provided a suitable bandgap for direct reduction of oxygen to H_(2)O_(2).Additionally,the isolated Gd^(3+)on WO_(3)surface can efficiently weaken the*OOH binding energy,increasing the activity and selectivity of direct reduction of oxygen to H_(2)O_(2),with a rate of 0.58 mmol L^(-1)g^(-1)h^(-1).The in-situ generated H_(2)O_(2)can be subsequently converted to·OH based on Fenton reaction,further contributed to the overall removal of organic pollutants.Our results demonstrate a cascade photocatalytic oxidation-Fenton reaction which can efficiently utilize photo-generated electrons and holes for organic pollutants treatment.展开更多
In this work,a novel amorphous molybdenum disulfide/manganese tungstate(MoS_(x)/MnWO_(4))hybrid in S-scheme heterojunction was designed and synthesized for photocatalytic water splitting to oxygen gen-eration under vi...In this work,a novel amorphous molybdenum disulfide/manganese tungstate(MoS_(x)/MnWO_(4))hybrid in S-scheme heterojunction was designed and synthesized for photocatalytic water splitting to oxygen gen-eration under visible light.In the hybrids,a strong chemical interlayer between amorphous MoS_(x)mi-crosheets and MnWO_(4)nanorods was created by partial substitution of Mo for W,which increases charge transportation efficiency by reducing charge transfer barrier,verified by the computational density functional theory(DFT)and photoelectrochemical tests.A 0.5 wt%MoS_(x)/MnWO_(4)system(2D/1D)displayed a remarkable enhancement in photocatalytic activity of O_(2)evolution,up to 267.8μmol g^(-1)under visi-ble light illumination(>420 nm).The formed S-scheme heterojunction structure efficiently promotes the utilization of solar light and separation efficiency of photo-generated charge carriers,leading to the improvement of photocatalytic water oxidation performance.展开更多
Photocatalytic aerobic oxidation desulfurization(PAODS)is a promising and sustainable alternative to conventional,energyintensive desulfurization techniques for petroleum products.However,its development is greatly pl...Photocatalytic aerobic oxidation desulfurization(PAODS)is a promising and sustainable alternative to conventional,energyintensive desulfurization techniques for petroleum products.However,its development is greatly plagued by the low capability in generating highly reactive oxygen species and sluggish kinetics of sulfide oxidation of reported photocatalysts.Here we report a class of MoO_(x)nanocluster decorated on ultrathin Mo-doped TiO_(2)nanosheet(MoO_(x)/MoTiO)catalyst for efficiently facilitating the photocatalytic aerobic oxidation of sulfides.We demonstrate that MoO_(x)/MoTiO can not only promote the generation of highly reactive singlet oxygen(^(1)O_(2))but also enhance the aerobic conversion of sulfides,which leads to a record dibenzothiophene oxidation activity of 3.90 mmol g^(-1)h^(-1).The multiple experimental characterizations and density functional theory calculations collectively reveal that the doped-Mo sites can interact with the photogenerated excitons,enabling directly energy transfer generation of^(1)O_(2)through a new exciton modulation mechanism,and the coordination unsaturated MoO_(x)clusters play the role of co-catalyst to enhance the separation of charge carriers,and effectively catalyze the reaction between sulfides and1O_(2)to form sulfones.展开更多
The increasing pollution and human demand for a cleaner environment have made achieving the environmental sustainability a current research focus.As a “green” technology,semiconductor photocatalysis is of great sign...The increasing pollution and human demand for a cleaner environment have made achieving the environmental sustainability a current research focus.As a “green” technology,semiconductor photocatalysis is of great significance to the environmental purification.Benefiting from the unique anisotropic crystal structure and electronic properties,layered photocatalytic nanomaterials show great potential for efficient photocatalytic environmental treatment.This review comprehensively summarizes the recent progress on layered photocatalytic nanomaterials for oxidation or reduction of pollutants in water and air along with the basic understanding of related mechanisms and developments in this field.First,the existing diversified layered photocatalysts are classified,and their different synthesis and modification strategies are discussed in detail to provide a comprehensive view of the material design that affects their photocatalytic performance.Subsequently,the extensive applications of the above-mentioned layered photocatalytic nanomaterials in environmental fields are systematically summarized,including photooxidation of water and air pollutants,and photoreduction of heavy metal pollutants,NO_(3)^(-),BrO_(3)^(-) and CO_(2).Finally,based on the current research achievements in layered photocatalysts for environmental remediation,the future development direction and challenges are proposed.展开更多
Photocatalytic oxidative desulfurization(PODS)over efficient earth-abundant catalysts to obtain clean fuel oil is of great importance for the environmental protection.In this work,a series of Ce-doped MIL-125-NH_(2)ph...Photocatalytic oxidative desulfurization(PODS)over efficient earth-abundant catalysts to obtain clean fuel oil is of great importance for the environmental protection.In this work,a series of Ce-doped MIL-125-NH_(2)photocatalysts were successfully prepared via a simple in-situ doping method and exhibited superior PODS performance of dibenzothiophene(DBT)under mild reaction conditions.The 1.0 mol%Ce/MIL-125-NH_(2)catalyst achieved 100%sulfur removal within 22 min at 30℃ under visible light illumination,which is mainly attributed to the high surface area and the formation of Ce-Ti-oxo clusters due to electronic coupling.The valence transformation of Ce^(4+)/Ce^(3+)and Ti^(4+)/Ti^(3+)redox mediators could not only expose abundant Lewis acid sites,but also promote the separation and transfer of photogenerated charges.In addition,increasing the reaction temperature has been demonstrated to be effective in promoting the PODS performance.Additionally,a thermo-enhanced PODS mechanism was proposed over Ce/MIL-125-NH_(2),demonstrating the great potential of thermal energy to promote the desulfurization activity.展开更多
In the process of methane(CH_(4))oxidation to methanol(CH3OH),CH3OH is more easily oxidized than CH_(4),resulting in inevitable peroxide phenomenon.In this work,we innovatively proposed a tandem reaction pathway to ob...In the process of methane(CH_(4))oxidation to methanol(CH3OH),CH3OH is more easily oxidized than CH_(4),resulting in inevitable peroxide phenomenon.In this work,we innovatively proposed a tandem reaction pathway to obtain a photocatalytic oxidation process of CH_(4) with high activity and selectivity.This work confirms that the methyl hydrogen peroxide(CH3OOH),the first product of CH_(4) oxidation by H_(2)O_(2),is then completely reduced to CH3OH in an electron-rich environment.Under irradiation,H_(2)O_(2) was excited into hydroxyl radicals(·OH)and hydroperoxyl radicals(·OOH)on brookite TiO_(2) photocatalyst.The·OH oxidized CH_(4) to form methyl radicals(·CH3),which then reacted with·OOH to form CH3OOH.CH3OOH gained electrons on Pt nanoparticles(NPs)and was reduced to CH3OH.At this point,low concentration of·OH was difficult to further oxidize CH3OH,so that it can exist stably.Under the conditions of room temperature(25°C)and atmospheric pressure,the productivity of CH3OH was 883μmol/(g·h),which was 4 times more than the reported photocatalytic CH_(4) oxidation system with the same reaction conditions,and the selectivity was 100%in liquid products(98.77%for all products).The photocatalyst showed excellent stability and maintained>85%product activity after 9 catalytic cycles.This work contributed to the development of highly efficient and selective CH_(4) photooxidation system under mild conditions.展开更多
Photocatalytic oxidation process for the degradation of volatile organic compounds(VOCs)contaminants is a promising technology.But until now,the low photocatalytic activity of the conventional TiO_(2) photocatalyst un...Photocatalytic oxidation process for the degradation of volatile organic compounds(VOCs)contaminants is a promising technology.But until now,the low photocatalytic activity of the conventional TiO_(2) photocatalyst under visible-light irradia-tion hinders the deployment of this technique for VOCs degradation.WO_(3) has been proved to be a suitable photocatalytic material for degradation of various VOCs as its appropriate band-gap,high stability and great capability.Nevertheless,the actual implementation of WO_(3) is still restricted by short lifetime of photoexcited charge carriers and low light energy conver-sion efficiency:its photocatalytic performance is needed to be improved.This review discusses the process of tungsten-based photocatalyst for removal of VOCs and summarizes a variety of strategies to improve the VOCs oxidation performances of WO_(3),such as controlling the morphology structure,engendering chemical defects,coupling heterojunction,doping suitable dopants and loading a co-catalyst.In addition,the practical application of tungsten-based photocatalyst is discussed.展开更多
A metal-free porphyrin covalent organic framework was employed as the heterogeneous photocatalyst for the synthesis of tetrahydroquinolines under aerobic conditions.With visible light irradiation of a catalytic amount...A metal-free porphyrin covalent organic framework was employed as the heterogeneous photocatalyst for the synthesis of tetrahydroquinolines under aerobic conditions.With visible light irradiation of a catalytic amount of H_(2)P-Bph-COF at room temperature,various substituted N,N-dimethylanilines and N-aryl maleimides were transformed to tetrahydroquinoline derivatives in moderate to good yields.This was the first example of the synthesis of tetrahydroquinolines via the photocatalytic aerobic annulation reaction employing the metal-free COF as the heterogeneous photocatalyst.展开更多
Charge separation and oxygen activation are two crucial factors in the photocatalytic oxidation of pollutants.and it is meaningful to simultaneously enhance charge separation and promote O2 activation.Herein,it is dem...Charge separation and oxygen activation are two crucial factors in the photocatalytic oxidation of pollutants.and it is meaningful to simultaneously enhance charge separation and promote O2 activation.Herein,it is demonstrated that the photocatalytic activity of porous In2O3is greatly improved after co-modifying nanosized CuO and Ag for oxidizing 2,4-dichlorophenol(2.4-DCP)and Co compared with that of individual In203.Based on the surface.photovoltage spectroscopy,02 temperature-programmed desorption,electron paramagnetic resonance spectroscopy and electrochemical results,the improved photoactivity is mainly attributed to the synergistic effects of enhancing photogenerated charge separation and promoting oxygen activation by respectively coupled nanosized CuO and Ag It is confirmed that the produced·O2^-radicals are dominant to induce the photocatalvtic oxidation of 2.4-DCP.This work offers an effective way to develop high-activity In203-based nanophotocatalysts for oxidizing pollutants.展开更多
基金supported by the National Key Research and Development Program of China(Nos.2017YFC0210500 and 2018YFC0213400)the National Natural Science Foundation of China(Nos.52070090 and 51868030)。
文摘La_(2)O_(3)/Bi_(2)O_(3)photocatalysts were prepared by impregnation of Bi_(2)O_(3)with an aqueous solution of lanthanum precursor followed by calcination at different temperatures.The composite materials were used for the first time for the photocatalytic removal of Hg~0 from a simulated flue gas under UV light irradiation.The results showed that the sample containing 6 wt.%La_(2)O_(3)and calcined at 500°C has the highest dispersion of the active sites,which was promoted by the strong interaction with the support(i.e.,the formation of Bi-O-La species).Since they are fully accessible on the surface,the material also exhibits excellent optical properties while the heterojunction formed in La_(2)O_(3)/Bi_(2)O_(3)promotes the separation and migration of photoelectron-hole pairs and thus Hg~0 oxidation efficiency is enhanced.The effects of the various factors(e.g.,the reaction temperature and composition of the simulated flue gas(i.e.,O_(2),NO,H_(2)O,and SO_(2)))on the efficiency of the Hg~0 photocatalytic oxidation were investigated.The results demonstrated that O_(2)and SO_(2)enhanced the efficiency of the reaction while the reaction temperature,NO,and H_(2)O had an inhibitory effect.
基金We are pleased to acknowledge research support from“Joint Research Grant to both Nankai University and Tianjin University”and“Trans-Century Training Program Foundation for the Talents”sponsored by the Ministry of Education,China,and the project under Tianjin’s Science and Technology Development Plan(Grant No.06YFGPSHO4200).
文摘TiO_(2) supported on active carbon fiber(TiO_(2)/ACF),an absorbable photocatalyst,is a new kind of material applied in air purification.In this paper,the influence of environmental temperature(T)and relative humidity(RH)on the gas-solid adsorption of toluene and the photocatalytic oxidation(PCO)efficiency of adsorbed toluene on TiO_(2)/ACF were studied,and then,the purification capability of TiO_(2)/ACF was estimated.PCO results showed that although the PCO efficiency increased under high RH and T levels,the amount of adsorption of toluene decreased.Moreover,quantitative analysis results of intermediates indicated that more environmental risk emerged when PCO of toluene was carried out at higher environmental T and RH levels because more toxic intermediates would be accumulated on the TiO_(2)/ACF.So,it is significant to control the environmental T and RH conditions in the application of the PCO technique.T 525uC and RH530% is the optimal condition for purifying toluene in our experimental system.
文摘Self-assembled supramolecular structures with efficient singlet oxygen(1O2)-generation ability are expected to enable photocatalytic oxidation reactions.Herein,we use two photosensitizers,perylene diimide and benzothiadiazole derivative,as the boards to prepare two barrel-shaped metallacages viametal-coordination-driven self-assembly.
基金the financial support of the Natural Science Foundation of China (21736003, 22178130 and 22005106)the Natural Science Foundation of Guangdong Province, China (2020A0505100008)the Science and Technology Program of Guangzhou (202206010024)。
文摘Lignocellulose shows significantly potential in sustainable conversion to high-quality fuel and valueadded chemicals with the demands for realizing the rapid cycle of carbon resources and helping to reach carbon neutrality in nature.Selective tailoring of α-O-4,β-O-4,etc.linkages in lignin has always been viewed as "death blow" for its depolymerization.Herein,novel sodium lignosulfonate(SL) modified Fe_(3)O_(4)/TiO_(2)(SL-Fe_(3)O_(4)/TiO_(2)) spherical particles have been developed and used as catalysts for selectively photocatalytic oxidative cleavage of organosolv lignin.As expected,80% selective conversion of lignin in C2-C4 esters has been achieved,while C-O bonds in lignin model compounds can be effectively cleaved.Other than normal hydroxyl radical-mediated photocatalytic depolymerization of lignin over TiO_(2)-based materials,in this contribution,mechanism studies indicate that photogenerated holes and superoxide anion radicals are main active species,which trigger the cleavage of α/β-O-4 bond,and the isotopelabeling study confirms the crucial factor of C_β-H dehydrogenation in cleavage of β-O-4 bonds.
基金supported by the BJAST High-level Innovation Team Program (No.BGS202001)the Beijing Postdoctoral Research Foundation (No.2022-ZZ-046)+3 种基金the National Natural and Science Foundation of China (No.51972026)the Japan Society for the Promotion of Science (JSPS)Grant-in-Aid for the Scientific Research (KAKENHI,Nos.16H06439 and 20H00297)the Dynamic Alliance for Open Innovations Bridging Human,Environment and Materials,the Cooperative Research Program of“Network Joint Research Center for Materials and Devices.”the scholarship granted to a visiting Ph.D.student of the Inter-University Exchange Project by the China Scholarship Council (CSC,No.201906460113)。
文摘The synthesis of oxygen vacancies(OVs)-modified TiO_(2)under mild conditions is attractive.In this work,OVs were easily introduced in TiO_(2)lattice during the hydrothermal doping process of trivalent iron ions.Theoretical calculations based on a novel charge-compensation structure model were employed with experimental methods to reveal the intrinsic photocatalytic mechanism of Fe-doped TiO_(2)(Fe-TiO_(2)).The OVs formation energy in Fe-TiO_(2)(1.12 eV)was only 23.6%of that in TiO_(2)(4.74 eV),explaining why Fe^(3+)doping could introduce OVs in the TiO_(2)lattice.The calculation results also indicated that impurity states introduced by Fe^(3+)and OVs enhanced the light absorption activity of TiO_(2).Additionally,charge carrier transport was investigated through the carrier lifetime and relative mass.The carrier lifetime of Fe-TiO_(2)(4.00,4.10,and 3.34 ns for 1at%,2at%,and 3at%doping contents,respectively)was longer than that of undoped TiO_(2)(3.22 ns),indicating that Fe^(3+) and OVs could promote charge carrier separation,which can be attributed to the larger relative effective mass of electrons and holes.Herein,Fe-TiO_(2)has higher photocatalytic indoor NO removal activity compared with other photocatalysts because it has strong light absorption activity and high carrier separation efficiency.
基金supported by National Natural Science Foundation of China(22369022)Technology Innovation Leading Program of Shaanxi(2022QFY07-03)。
文摘The efficiency of photocatalytic overall water splitting was mainly limited by the slow reaction kinetics of water oxidation.How to design effective surface active site to overcome the slow water oxidation reaction was a major challenge.Here,we propose a strategy to accelerate surface water oxidation through the fabrication spatially separated double active sites.FeCoPi/Bi_(4)NbO_(8)Cl-OVs photocatalyst with spatially separated double active site was prepared by hydrogen reduction photoanode deposition method.Due to the high matching of the spatial loading positions of FeCoPi and OVs with the photogenerated charge distribution of Bi_(4)NbO_(8)Cl and corresponding reaction mechanisms of substrate,the FeCoPi and OVs on the(001)and(010)crystal planes of Bi_(4)NbO_(8)Cl photocatalyst provided surface active site for water oxidation reaction and electron shuttle reaction(Fe^(3+)/Fe^(2+)),respectively.Under visible light irradiation,the evolution O_(2)rate of FeCoPi/Bi_(4)NbO_(8)Cl OVs was 16.8μmol h^(-1),as 32.9 times as Bi_(4)NbO_(8)Cl.Furthermore,a hydrogen evolution co-catalyst PtRu@Cr_(2)O_(3)was prepared by sequential photodeposition method.Due to the introduction of Ru,the Schottky barrier between PbTiO_(3)and Pt was effectively reduced,which promoted the transfer of photogenerated electrons to PtRu@Cr_(2)O_(3)thermodynamically,the evolution H_(2)rate on PtRu@Cr_(2)O_(3)/PbTiO_(3)increased to 664.8 times.On based of the synchronous enhancement of the water oxidation performance on FeCoPi/Bi_(4)NbO_(8)Cl-OVs and water reduction performance on PtRu@Cr_(2)O_(3)/PbTiO_(3),a novel Z-Scheme photocatalytic overall water splitting system(FeCoPi/Bi_(4)NbO_(8)Cl-OVs)mediated by Fe^(3+)/Fe^(2+)had successfully constructed.Under visible light irradiation,the evolution rates of H_(2)and O_(2)were 2.5 and 1.3μmol h^(-1),respectively.This work can provide some reference for the design of active site and the controllable synthesis of OVs spatial position.On the other hand,the hydrogen evolution co catalyst(PtRu@Cr_(2)O_(3))and the co catalyst FeCoPi for oxygen evolution contributed to the construction of an overall water splitting system.
文摘This research focuses on the evaluation of diverse approaches for removing formaldehyde from indoor environments,which is a significant concern for indoor air quality.The study systematically examines physical,chemical,and biological methods to ascertain their effectiveness in formaldehyde mitigation.Physical methods,including air circulation and adsorption,particularly with activated carbon and molecular sieves,are assessed for their efficiency in various concentration scenarios.Chemical methods,such as photocatalytic oxidation using titanium dioxide and plasma technology,are analyzed for their ability to decompose formaldehyde into non-toxic substances.Additionally,biological methods involving plant purification and microbial transformation are explored for their eco-friendly and sustainable removal capabilities.The paper concludes that while each method has its merits,a combined approach may offer the most effective solution for reducing indoor formaldehyde levels.The study underscores the need for further research to integrate these methods in a practical,cost-effective,and environmentally sustainable manner,highlighting their potential to improve indoor air quality significantly.
基金supported by the National Natural Science Foundation of China(21731002,21975104,22101099,22150004,22271120)Guangdong Major Project of Basic and Applied Research(2019B030302009)+1 种基金the Outstanding Innovative Talents Cultivation Funded Programs for Doctoral Students of Jinan University(2022CXB007)the Fundamental Research Funds for the Central Universities and Jinan University(21621035)。
文摘Photocatalytic aerobic oxidation reactions are largely governed by the efficiency of charge separation and subsequent reactive oxygen species(ROS) generation. Herein, we report a polarization engineering strategy to promote the charge separation and ROS generation efficiency by substituting the benzene unit with furan/thiophene in porous organic polymers(POPs). Benefiting from the extent of local polarization, the thiophene-containing POP(JNU-218) exhibits the best photocatalytic performance in aerobic oxidation reactions, with a yield much higher than those for the furan-containing POP(JNU-217) and the benzenecontaining POP(JNU-216). Experimental studies and theoretical calculations reveal that the increase of local polarization can indeed reduce the exciton binding energy, and therefore facilitate the separation of electron-hole pairs. This work demonstrates a viable strategy to tune charge separation and ROS generation efficiency by modulating the dipole moments of the building blocks in porous polymeric organic semiconductors.
基金FAPESP,FAPEMIG,CAPES and CNPq for the financial support.
文摘In the present work, the hybrid catalyst films of TiO2/CuO containing up to 10% in mol of copper were deposited onto glass surface. Precursor solutions were obtained by citrate precursor method. Films were porous and the average particle size was 20 nm determined by FEG-SEM analysis. The photocatalytic activities of these films were studied using Rhodamine B as a target compound in a fixed bed reactor developed in our laboratory and UV lamp. It was observed that the addition of copper to TiO2 increased significantly its photocatalytic activity during the oxidation of Rhodamine B. The degradation exceeded 90% within 48 hours of irradiation compared to 38% when pure TiO2 was used. Moreover, there was a reduction in the particles band gap energy when compared to that of pure TiO2. These results indicate that the TiO2/CuO films are promising catalysts for the development of fixed bed reactors to be used to treat effluents containing azo dyes.
基金support by the National Natural Science Foundation of China(No.21972028)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB36000000).
文摘Partial oxidation of methane into primary oxidation products with high value remains a challenge.In this work,photocatalytic oxidation of methane(CH_(4))with high methyl hydroperoxide(CH_(3)OOH)selectivity is achieved using pure titanium oxide(TiO_(2))without any cocatalyst at room temperature and atmospheric pressure.The CH_(3)OOH production rate can reach up to 2050±88μmol·g^(-1)·h^(-1) at pH≈7.0 with 100%selectivity in the liquid product.The stable reaction cycle can reach more than 30 times.This low-cost system achieves superior CH_(4) conversion activity and selectivity compared with similar work.The energy of hydrogen peroxide(H_(2)O_(2))to adsorbed hydroperoxyl radical(^(*)OOH)has a significantly lower reaction energy than conversion to adsorbed hydroxyl radical(*OH)on the(210)surface of the TiO_(2).The^(*)OOH preferentially combines with methyl radical(·CH_(3))to form the most energetically favorable CH_(3)OOH.The mild oxidative environment of this system prevents the reduction of CH_(3)OOH to CH_(3)OH or over-oxidation of CH_(4),which ensures the final CH_(3)OOH with high selectivity and stability.This work provided a low-cost but highly efficient method to achieve partial oxidation with superior selectivity,i.e.,to convert CH_(4) into high-value chemicals.
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supported by Natural Science Foundation of Zhejiang Province(No.LR21B07002)National Natural Science Foundation of China(Nos.22176170,21976152)the Open Research Program of Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province,Westlake University。
文摘This work reported the lanthanide ion(Gd^(3+))doped tungsten trioxide(Gd-WO_(3))nanocrystal for remarkable promoted photocatalytic degradation of organic pollutants and simultaneous in-situ H_(2)O_(2)production.With doped lanthanide ion(Gd^(3+)),Gd-WO_(3)showed a much broad and enhanced solar light absorption,which not only promoted the photocatalytic degradation efficiency of organic compounds,but also provided a suitable bandgap for direct reduction of oxygen to H_(2)O_(2).Additionally,the isolated Gd^(3+)on WO_(3)surface can efficiently weaken the*OOH binding energy,increasing the activity and selectivity of direct reduction of oxygen to H_(2)O_(2),with a rate of 0.58 mmol L^(-1)g^(-1)h^(-1).The in-situ generated H_(2)O_(2)can be subsequently converted to·OH based on Fenton reaction,further contributed to the overall removal of organic pollutants.Our results demonstrate a cascade photocatalytic oxidation-Fenton reaction which can efficiently utilize photo-generated electrons and holes for organic pollutants treatment.
基金This work was financially supported by the Knowl-edge Innovation Program of Wuhan-Shuguang Project(No.2022020801020366)the Natural Science Foundation of Hubei Province(No.2019CFB556),the Science Research Foundation of Wuhan Institute of Technology(No.K201939)the Innovative Team program of Natural Science Foundation of Hubei Province(No.2021CFA032).Thanks are also acknowledged for the support from Tianhe 2 high performance computing Center in Lvliang.
文摘In this work,a novel amorphous molybdenum disulfide/manganese tungstate(MoS_(x)/MnWO_(4))hybrid in S-scheme heterojunction was designed and synthesized for photocatalytic water splitting to oxygen gen-eration under visible light.In the hybrids,a strong chemical interlayer between amorphous MoS_(x)mi-crosheets and MnWO_(4)nanorods was created by partial substitution of Mo for W,which increases charge transportation efficiency by reducing charge transfer barrier,verified by the computational density functional theory(DFT)and photoelectrochemical tests.A 0.5 wt%MoS_(x)/MnWO_(4)system(2D/1D)displayed a remarkable enhancement in photocatalytic activity of O_(2)evolution,up to 267.8μmol g^(-1)under visi-ble light illumination(>420 nm).The formed S-scheme heterojunction structure efficiently promotes the utilization of solar light and separation efficiency of photo-generated charge carriers,leading to the improvement of photocatalytic water oxidation performance.
基金supported by the National Natural Science Foundation of China(21808098,52261135633,52025133)the National Key R&D Program of China(2022YFE0128500)+1 种基金the Project of Shandong Province Higher Educational Science(2022KJ122)Yantai Science and Technology Development Program(2019XDHZ106)。
文摘Photocatalytic aerobic oxidation desulfurization(PAODS)is a promising and sustainable alternative to conventional,energyintensive desulfurization techniques for petroleum products.However,its development is greatly plagued by the low capability in generating highly reactive oxygen species and sluggish kinetics of sulfide oxidation of reported photocatalysts.Here we report a class of MoO_(x)nanocluster decorated on ultrathin Mo-doped TiO_(2)nanosheet(MoO_(x)/MoTiO)catalyst for efficiently facilitating the photocatalytic aerobic oxidation of sulfides.We demonstrate that MoO_(x)/MoTiO can not only promote the generation of highly reactive singlet oxygen(^(1)O_(2))but also enhance the aerobic conversion of sulfides,which leads to a record dibenzothiophene oxidation activity of 3.90 mmol g^(-1)h^(-1).The multiple experimental characterizations and density functional theory calculations collectively reveal that the doped-Mo sites can interact with the photogenerated excitons,enabling directly energy transfer generation of^(1)O_(2)through a new exciton modulation mechanism,and the coordination unsaturated MoO_(x)clusters play the role of co-catalyst to enhance the separation of charge carriers,and effectively catalyze the reaction between sulfides and1O_(2)to form sulfones.
基金jointly supported by the National Natural Science Foundation of China(Nos.51972288 and 51672258)the Fundamental Research Funds for the Central Universities(No.2652018287)。
文摘The increasing pollution and human demand for a cleaner environment have made achieving the environmental sustainability a current research focus.As a “green” technology,semiconductor photocatalysis is of great significance to the environmental purification.Benefiting from the unique anisotropic crystal structure and electronic properties,layered photocatalytic nanomaterials show great potential for efficient photocatalytic environmental treatment.This review comprehensively summarizes the recent progress on layered photocatalytic nanomaterials for oxidation or reduction of pollutants in water and air along with the basic understanding of related mechanisms and developments in this field.First,the existing diversified layered photocatalysts are classified,and their different synthesis and modification strategies are discussed in detail to provide a comprehensive view of the material design that affects their photocatalytic performance.Subsequently,the extensive applications of the above-mentioned layered photocatalytic nanomaterials in environmental fields are systematically summarized,including photooxidation of water and air pollutants,and photoreduction of heavy metal pollutants,NO_(3)^(-),BrO_(3)^(-) and CO_(2).Finally,based on the current research achievements in layered photocatalysts for environmental remediation,the future development direction and challenges are proposed.
基金supported by the National Key Research and Development Program of China(No.2021YFB3500700)the National Natural Science Foundation of China(No.21976054)Fundamental Research Funds for the Central Universities(No.FRFTP-20-005A3)。
文摘Photocatalytic oxidative desulfurization(PODS)over efficient earth-abundant catalysts to obtain clean fuel oil is of great importance for the environmental protection.In this work,a series of Ce-doped MIL-125-NH_(2)photocatalysts were successfully prepared via a simple in-situ doping method and exhibited superior PODS performance of dibenzothiophene(DBT)under mild reaction conditions.The 1.0 mol%Ce/MIL-125-NH_(2)catalyst achieved 100%sulfur removal within 22 min at 30℃ under visible light illumination,which is mainly attributed to the high surface area and the formation of Ce-Ti-oxo clusters due to electronic coupling.The valence transformation of Ce^(4+)/Ce^(3+)and Ti^(4+)/Ti^(3+)redox mediators could not only expose abundant Lewis acid sites,but also promote the separation and transfer of photogenerated charges.In addition,increasing the reaction temperature has been demonstrated to be effective in promoting the PODS performance.Additionally,a thermo-enhanced PODS mechanism was proposed over Ce/MIL-125-NH_(2),demonstrating the great potential of thermal energy to promote the desulfurization activity.
基金support by the National Natural Science Foundation of China(No.21972028)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB36000000).
文摘In the process of methane(CH_(4))oxidation to methanol(CH3OH),CH3OH is more easily oxidized than CH_(4),resulting in inevitable peroxide phenomenon.In this work,we innovatively proposed a tandem reaction pathway to obtain a photocatalytic oxidation process of CH_(4) with high activity and selectivity.This work confirms that the methyl hydrogen peroxide(CH3OOH),the first product of CH_(4) oxidation by H_(2)O_(2),is then completely reduced to CH3OH in an electron-rich environment.Under irradiation,H_(2)O_(2) was excited into hydroxyl radicals(·OH)and hydroperoxyl radicals(·OOH)on brookite TiO_(2) photocatalyst.The·OH oxidized CH_(4) to form methyl radicals(·CH3),which then reacted with·OOH to form CH3OOH.CH3OOH gained electrons on Pt nanoparticles(NPs)and was reduced to CH3OH.At this point,low concentration of·OH was difficult to further oxidize CH3OH,so that it can exist stably.Under the conditions of room temperature(25°C)and atmospheric pressure,the productivity of CH3OH was 883μmol/(g·h),which was 4 times more than the reported photocatalytic CH_(4) oxidation system with the same reaction conditions,and the selectivity was 100%in liquid products(98.77%for all products).The photocatalyst showed excellent stability and maintained>85%product activity after 9 catalytic cycles.This work contributed to the development of highly efficient and selective CH_(4) photooxidation system under mild conditions.
基金This work was financially supported by the National Natural Science Foundation of China(NSFC,Grant No.51472194)the NSF of Hubei Province(Grant No.2016CFA078)the National Basic Research Program of China(973 Program,Grant No.2013CB632402).
文摘Photocatalytic oxidation process for the degradation of volatile organic compounds(VOCs)contaminants is a promising technology.But until now,the low photocatalytic activity of the conventional TiO_(2) photocatalyst under visible-light irradia-tion hinders the deployment of this technique for VOCs degradation.WO_(3) has been proved to be a suitable photocatalytic material for degradation of various VOCs as its appropriate band-gap,high stability and great capability.Nevertheless,the actual implementation of WO_(3) is still restricted by short lifetime of photoexcited charge carriers and low light energy conver-sion efficiency:its photocatalytic performance is needed to be improved.This review discusses the process of tungsten-based photocatalyst for removal of VOCs and summarizes a variety of strategies to improve the VOCs oxidation performances of WO_(3),such as controlling the morphology structure,engendering chemical defects,coupling heterojunction,doping suitable dopants and loading a co-catalyst.In addition,the practical application of tungsten-based photocatalyst is discussed.
基金the financial support from the National Natural Science Foundation of China(Nos.22101158,22171169,21971153 and 21772116)the Natural Science Foundation of Shandong Province(No.ZR2021MB088)+2 种基金the Taishan Scholars Climbing Program of Shandong Provincethe Taishan Scholar Project of Shandong Provincethe Major Basic Research Projects of Shandong Natural Science Foundation(No.ZR2020ZD32)。
文摘A metal-free porphyrin covalent organic framework was employed as the heterogeneous photocatalyst for the synthesis of tetrahydroquinolines under aerobic conditions.With visible light irradiation of a catalytic amount of H_(2)P-Bph-COF at room temperature,various substituted N,N-dimethylanilines and N-aryl maleimides were transformed to tetrahydroquinoline derivatives in moderate to good yields.This was the first example of the synthesis of tetrahydroquinolines via the photocatalytic aerobic annulation reaction employing the metal-free COF as the heterogeneous photocatalyst.
基金Supported by the National Natural Science Foundation of China(Nos.U1805255,21905080)the Basic Researceh Fund of Heilongiang University,China(No.RCCXY1201808).
文摘Charge separation and oxygen activation are two crucial factors in the photocatalytic oxidation of pollutants.and it is meaningful to simultaneously enhance charge separation and promote O2 activation.Herein,it is demonstrated that the photocatalytic activity of porous In2O3is greatly improved after co-modifying nanosized CuO and Ag for oxidizing 2,4-dichlorophenol(2.4-DCP)and Co compared with that of individual In203.Based on the surface.photovoltage spectroscopy,02 temperature-programmed desorption,electron paramagnetic resonance spectroscopy and electrochemical results,the improved photoactivity is mainly attributed to the synergistic effects of enhancing photogenerated charge separation and promoting oxygen activation by respectively coupled nanosized CuO and Ag It is confirmed that the produced·O2^-radicals are dominant to induce the photocatalvtic oxidation of 2.4-DCP.This work offers an effective way to develop high-activity In203-based nanophotocatalysts for oxidizing pollutants.
