As a green and sustainable technology,heterogeneous photocatalysis using semiconductors has received much attention during the past decades because of its potential to address energy and environmental problems. Among ...As a green and sustainable technology,heterogeneous photocatalysis using semiconductors has received much attention during the past decades because of its potential to address energy and environmental problems. Among various semiconductors,TiO2 has been regarded as the best and most widely investigated photocatalyst in the past 10 years. Based on the fundamentals of photocatalysis and surface chemistry of TiO2 nanomaterials,we herein summarize and discuss the achievements in the different surface modification strategies employed to date such as surface doping and sensitization,construction of surface heterojunctions,loading of nano-sized co-catalysts,increase in the accessible surface areas,and usage of surface F effects and exposure of highly reactive facets. Especially,the interesting synergistic effects of these different surface modification strategies deserve more attention in the near future. Studying these important advances in photocatalysis fundamentals,and surface chemistry and modification may offer new opportunities for designing highly efficient TiO2-based and non-TiO2-based photocatalysts for solar fuel production,environmental remediation,organic photosynthesis,and other related fields such as solar cell device fabrication,thermal catalysis,and separation and purification.展开更多
Electron-hole separation is a critical step to achieving efficient photocatalysis, towards which use of co-catalysts has become a widely used strategy. Despite the tremendous efforts and demonstrated functions of nobl...Electron-hole separation is a critical step to achieving efficient photocatalysis, towards which use of co-catalysts has become a widely used strategy. Despite the tremendous efforts and demonstrated functions of noble metal co-catalysts, seeking noble metal-free co-catalysts will always be the goal when designing cost- effective, high-performance hybrid photocatalysts. In this work, we demonstrate that MoS~ nanosheets with 1T phase （i.e., octahedral phase） can function as a co-catalyst with multiple merits： （1） Noble-metal-free; （2） high mobility for charge transport; （3） high density of active sites for H2 evolution on basal planes; （4） good performance stability; （5） high light transparency. As demonstrated in both photocatalytic hydrogen production and Rhodamine B degradation, the developed hybrid structure with TiO2 exhibits excellent performance, in sharp contrast to bare TiO2 and the hybrid counterpart with 2H-MoS2.展开更多
Silicon carbide （SIC） has been considered a promising metal-free photocatalyst due to its unique photoelectrical properties and thermal/chemical stability. However, its performance suffers from the fast recombinatio...Silicon carbide （SIC） has been considered a promising metal-free photocatalyst due to its unique photoelectrical properties and thermal/chemical stability. However, its performance suffers from the fast recombination of charge carriers. Herein, we report mesoporous SiC nanofibers with in situ embedded graphitic carbon （SiC NFs-Cx） synthesized via a one-step carbothermal reduction between electrospun carbon nanofibers and Si powders. In the absence of a noble metal co-catalyst, the hydrogen evolution efficiency of SiC NFs-Cx is significantly improved under both simulated solar light （180.2 μmol.g-1.h-1） and visible light irradiation （31.0 ~amol-g-l-h-~） in high-pH solution. The efficient simultaneous separation of charge carriers plays a critical role in the high photocatalytic activity. The embedded carbon can swiftly transfer the photogenerated electrons and improve light absorption, whereas the additional hydroxyl anions （OH-） in high- pH solution can accelerate the trapping of holes. Our results demonstrate that the production of SiC NFs-Cx, which contains exclusively earth-abundant elements, scaled up, and is environmentally friendly, has great potential for practical applications. This work may provide a new pathway for designing stable, low- cost, high efficiency, and co-catalyst-free photocatalysts.展开更多
Environmental pollution and energy deficiency represent major problems for the sustainability of the modern world. Photocatalysis has recently emerged as an effective and environmentally friendly technique to address ...Environmental pollution and energy deficiency represent major problems for the sustainability of the modern world. Photocatalysis has recently emerged as an effective and environmentally friendly technique to address some of these sustainability issues,although the key to the success of this approach is dependent on the photocatalysts themselves. Based on their attractive physic chemical properties,including their ultrahigh surface areas,homogeneous active sites and tunable functionality,metal-organic frameworks（MOFs） have become interesting platforms for the development of solar energy conversion devices. Furthermore,MOFs have recently been used in a wide variety of applications,including heterogeneous photocatalysis for pollutant degradation,organic transformations,hydrogen production and CO2 reduction. In this review,we have highlighted recent progress towards the application of MOFs in all of these areas. We have collected numerous reported examples of the use of MOFs in these areas,as well as providing some analysis of the key factors influencing the efficiency of these systems. Moreover,we have provided a detailed discussion of new strategies that have been developed for enhancing the photocatalytic activity of MOFs. Finally,we have provided an outlook for this area in terms of the future challenges and potential prospects for MOFs in photocatalysis.展开更多
Photocatalytic N2 fixation involves a nitrogen reduction reaction on the surface of the photocatalyst to convert N2 into ammonia.Currently,the adsorption of N2 is the limiting step for the N2 reduction reaction on the...Photocatalytic N2 fixation involves a nitrogen reduction reaction on the surface of the photocatalyst to convert N2 into ammonia.Currently,the adsorption of N2 is the limiting step for the N2 reduction reaction on the surface of the catalyst.Based on the concept of photocatalytic water splitting,the photocatalytic efficiency can be greatly enhanced by introducing a co-catalyst.In this report,we proposed a new strategy,namely,the loading of a NiS co-catalyst on CdS nanorods for photocatalytic N2 fixation.Theoretical calculation results indicated that N2 was effectively adsorbed onto the NiS/CdS surface.Temperature programmed desorption studies confirmed that the N2 molecules preferred to adsorb onto the NiS/CdS surface.Linear sweep voltammetry results revealed that the overpotential of the N2 reduction reaction was reduced by loading NiS.Furthermore,transient photocurrent and electrochemical impedance spectroscopy indicated that the charge separation was enhanced by introducing NiS.Photocatalytic N2 fixation was carried out in the presence of the catalyst dispersed in water without any sacrificial agent.As a result,1.0 wt% NiS/CdS achieved an ammonia production rate of 2.8 and 1.7 mg L-1 for the first hour under full spectrum and visible light(λ>420 nm),respectively.The catalyst demonstrated apparent quantum efficiencies of 0.76%,0.39% and 0.09% at 420,475 and 520 nm,res pectively.This study provides a new method to promote the photocatalytic efficiency of N2 fixation.展开更多
Hydrogen production by photolysis of water by sunlight is an environmentally-friendly preparation technology for renewable energy.Graphitic carbon nitride(g-C3N4),despite with obvious catalytic effect,is still unsatis...Hydrogen production by photolysis of water by sunlight is an environmentally-friendly preparation technology for renewable energy.Graphitic carbon nitride(g-C3N4),despite with obvious catalytic effect,is still unsatisfactory for hydrogen production.In this work,phosphorus element is incorporated to tune g-C3N4's property through calcinating the mixture of g-C3N4 and Na H2PO2,sacrificial agent and co-catalyst also been supplied to help efficient photocatalytic hydrogen production.Phosphorus(P)doped g-C3N4 samples(PCN-S)were prepared,and their catalytic properties were studied.X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM)and ultraviolet diffuse reflection(UV-DRS)were used to study their structures and morphologies.The results show that the reaction rate of PCN-S is 318μmol·h^-1·g^-1,which is 2.98 times as high as pure carbon nitride nanosheets(CN)can do.Our study paves a new avenue,which is simple,environment-friendly and sustainable,to synthesize highly efficient P doping g-C3N4 nanosheets for solar energy conversion.展开更多
Solar-light-driven CO_(2) reduction CO to CH_(4) and C2H6 is a complex process involving multiple elementary reactions and energy barriers.Therefore,achieving high CH_(4) activity and selectivity remains a significant...Solar-light-driven CO_(2) reduction CO to CH_(4) and C2H6 is a complex process involving multiple elementary reactions and energy barriers.Therefore,achieving high CH_(4) activity and selectivity remains a significant challenge.Here,we integrate bifunctional Cu2O and Cu-MOF(MOF=metal-organic framework)core–shell co-catalysts(Cu2O@Cu-MOF)with semiconductor TiO_(2).Experiments and theoretical calculations demonstrate that Cu2O(Cu+facilitates charge separation)and Cu-MOF(Cu2+improves the CO_(2) adsorption and activation)in the core–shell structure have a synergistic effect on photocatalytic CO_(2) reduction,reducing the formation barrier of the key intermediate*COOH and*CHO.The photocatalyst exhibits high CH_(4) yield(366.0μmol·g^(-1)·h^(-1)),efficient electron transfer(3283μmol·g^(-1)·h^(-1))and hydrocarbon selectivity(95.5%),which represents the highest activity of Cu-MOF-based catalysts in photocatalytic CO_(2) reduction reaction.This work provides a strategy for designing efficient photocatalysts from the perspective of precise regulation of components.展开更多
As BiVO4 is one of the most popular visible-light-responding photocatalysts, it has been widely used for visiblelight-driven water splitting and environmental purification. However, the typical photocatalytic activity...As BiVO4 is one of the most popular visible-light-responding photocatalysts, it has been widely used for visiblelight-driven water splitting and environmental purification. However, the typical photocatalytic activity of unmodified BiVO4 for the degradation of organic pollutants is still not impressive. To address this limitation, we studied Fe2O3-modified porous BiVO4 nanoplates. Compared with unmodified BiVO4, the Fe2O3-modified porous Bi VO4 nanoplates showed significantly enhanced photocatalytic activities in decomposing both dye and colorless pollutant models, such as rhodamine B(Rh B) and phenol,respectively. The pseudo-first-order reaction rate constants for the degradation of RhB and phenol on Fe2O3-modified BiVO4 porous nanoplates are 27 and 31 times larger than that of pristine Bi VO4, respectively. We also found that the Fe2O3 may act as an efficient non-precious metal co-catalyst, which is responsible for the excellent photocatalytic activity of Fe2O3/BiVO4.Graphical Abstract Fe2O3, as a cheap and efficient co-catalyst, could greatly enhance the photocatalytic activity of Bi VO4 porous nanoplates in decomposing organic pollutants.展开更多
Graphitic carbon nitride(g-C3N4)was synthesized by heating melamine and was then treated with sodium hydroxide solution under a hydrothermal condition to obtain g-C3N4 with a large specific surface area(HSSA).HSSA sho...Graphitic carbon nitride(g-C3N4)was synthesized by heating melamine and was then treated with sodium hydroxide solution under a hydrothermal condition to obtain g-C3N4 with a large specific surface area(HSSA).HSSA shows higher photocatalytic activity for decomposition of acetaldehyde than that of original g-C3N4.HSSA was modified with RuO2 as a co-catalyst by the impregnation method.HSSA loaded with 0.05 wt%RuO2 shows the highest photocatalytic activity for acetaldehyde decomposition under visible light(k=455 nm).展开更多
Assembly of two-dimensional(2D)metal–organic layers(MOLs)based on the hard and soft acid–base theorem represents an exquisite strategy for the construction of photocatalytic platforms in virtue of the highly exposed...Assembly of two-dimensional(2D)metal–organic layers(MOLs)based on the hard and soft acid–base theorem represents an exquisite strategy for the construction of photocatalytic platforms in virtue of the highly exposed active sites,much improved mass transport,and greatly elevated stability.Herein,nanocages composed of MOLs are produced for the first time through a cosolvent approach utilizing zirconium-based UiO-66-(OH)2 as the structural precursor.To endow the catalytic activity for CO_(2) conversion,single atomic Co^(2+)sites are appended to the Zr-oxo nodes of the MOL cages,demonstrating a remarkable CO yield of 7.74 mmol·g^(-1)·h^(-1) and operational stability of 97.1%product retention after five repeated cycles.Such an outstanding photocatalytic performance is mainly attributed to the unique nanocage morphology comprising enormous 2D nanosheets for augmented Co^(2+)exposure and the abundant surface hydroxyl groups for local CO_(2) enrichment.This work underlines the tailoring of both metal–organic framework(MOF)morphology and functionality to boost the turnover rate of photocatalytic CO_(2) reduction reaction(CO_(2)RR).展开更多
Modification of nickel sulfide cocatalysts is considered to be a promising approach for efficient enhancement of the photocatalytic hydrogen production performance of g-C3N4.Providing more NiS cocatalyst to function a...Modification of nickel sulfide cocatalysts is considered to be a promising approach for efficient enhancement of the photocatalytic hydrogen production performance of g-C3N4.Providing more NiS cocatalyst to function as active sites of g-C3N4 is still highly desirable.To realize this goal,in this work,a facile sulfur-mediated photodeposition approach was developed.Specifically,photogenerated electrons excited by visible light reduce the S molecules absorbed on g-C3N4 surface to S^2‒,and subsequently NiS cocatalyst is formed in situ on the g-C3N4 surface by a combination of Ni2+and S2‒due to their small solubility product constant(Ksp=3.2×10^‒19).This approach has several advantages.The NiS cocatalyst is clearly in situ deposited on the photogenerated electron transfer sites of g-C3N4,and thus provides more active sites for H2 production.In addition,this method utilizes solar energy with mild reaction conditions at room temperature.Consequently,the synthesized NiS/g-C3N4 photocatalyst achieves excellent hydrogen generation performance with the performance of the optimal sample(244μmol h^‒1 g^‒1)close to that of 1 wt%Pt/g-C3N4(316μmol h^‒1 g^‒1,a well-known excellent photocatalyst).More importantly,the present sulfur-mediated photodeposition route is versatile and facile and can be used to deposit various metal sulfides such as CoSx,CuSx and AgSx on the g-C3N4 surface,and all the resulting metal sulfide-modified g-C3N4 photocatalysts exhibit improved H2-production performance.Our study offers a novel insight for the synthesis of high-efficiency photocatalysts.展开更多
Photocatalytic degradation and hydrogen production using solar energy through semiconductor photocatalysts are deemed to be a powerful approach for solving environmental and energy crisis.However,the biggest challenge...Photocatalytic degradation and hydrogen production using solar energy through semiconductor photocatalysts are deemed to be a powerful approach for solving environmental and energy crisis.However,the biggest challenge in photocatalysis is the efficient separation of photo-induced carriers.To this end,we report that the mesoporous TiO_(2)nanoparticles are anchored on highly conductive Ti_(3)C_(2)MXene co-catalyst by electrostatic self-assembly strategy.The constructed mesoporous TiO_(2)/Ti_(3)C_(2)composites display that the mesoporous TiO_(2)nanoparticles are uniformly distributed on the surface of layer structured Ti_(3)C_(2)nanosheets.More importantly,the as-obtained mesoporous TiO_(2)/Ti_(3)C_(2)composites reveal the significantly enhanced light absorption performance,photo-induced carriers separation and transfer ability,thus boosting the photocatalytic activity.The photocatalytic methyl orange degradation efficiency of mesoporous TiO_(2)/Ti_(3)C_(2)composite with an optimized Ti_(3)C_(2)content(3 wt%)can reach 99.6%within 40 min.The capture experiments of active species confirm that the·O_(2)-and·OH play major role in photocatalytic degradation process.Furthermore,the optimized mesoporous TiO_(2)/Ti_(3)C_(2)composite also shows an excellent photocatalytic H2 production rate of 218.85μmol g^(-1)h^(-1),resulting in a 5.6 times activity as compared with the pristine mesoporous TiO_(2)nanoparticles.This study demonstrates that the MXene family materials can be applied as highly efficient noble-metal-free co-catalysts in the field of photocatalysis.展开更多
基金supported by the Industry and Research Collaborative Innovation Major Projects Of Guangzhou(201508020098)the National Natural Science Foundation of China(20906034+2 种基金21173088and 21207041)the State Key Laboratory of Advanced Technology for Material Synthesis and Processing,Wuhan University of Technology(2015-KF-7)~~
文摘As a green and sustainable technology,heterogeneous photocatalysis using semiconductors has received much attention during the past decades because of its potential to address energy and environmental problems. Among various semiconductors,TiO2 has been regarded as the best and most widely investigated photocatalyst in the past 10 years. Based on the fundamentals of photocatalysis and surface chemistry of TiO2 nanomaterials,we herein summarize and discuss the achievements in the different surface modification strategies employed to date such as surface doping and sensitization,construction of surface heterojunctions,loading of nano-sized co-catalysts,increase in the accessible surface areas,and usage of surface F effects and exposure of highly reactive facets. Especially,the interesting synergistic effects of these different surface modification strategies deserve more attention in the near future. Studying these important advances in photocatalysis fundamentals,and surface chemistry and modification may offer new opportunities for designing highly efficient TiO2-based and non-TiO2-based photocatalysts for solar fuel production,environmental remediation,organic photosynthesis,and other related fields such as solar cell device fabrication,thermal catalysis,and separation and purification.
文摘Electron-hole separation is a critical step to achieving efficient photocatalysis, towards which use of co-catalysts has become a widely used strategy. Despite the tremendous efforts and demonstrated functions of noble metal co-catalysts, seeking noble metal-free co-catalysts will always be the goal when designing cost- effective, high-performance hybrid photocatalysts. In this work, we demonstrate that MoS~ nanosheets with 1T phase （i.e., octahedral phase） can function as a co-catalyst with multiple merits： （1） Noble-metal-free; （2） high mobility for charge transport; （3） high density of active sites for H2 evolution on basal planes; （4） good performance stability; （5） high light transparency. As demonstrated in both photocatalytic hydrogen production and Rhodamine B degradation, the developed hybrid structure with TiO2 exhibits excellent performance, in sharp contrast to bare TiO2 and the hybrid counterpart with 2H-MoS2.
基金The work was financially supported by National Natural Science Foundation of China （Nos. 51173202 and 51203182）, Hunan Provincial Natural Science Foundation of China （No. 13JJ4009）, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing （Wuhan University of Technology） （No. 2014-KF-10）, the State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology （No. G201501） and Research Project of National University of Defense Technology （No. JC13-01-05）. This work was also supported by Aid program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province and Aid Program for Innovative Group of National University of Defense Technology.
文摘Silicon carbide （SIC） has been considered a promising metal-free photocatalyst due to its unique photoelectrical properties and thermal/chemical stability. However, its performance suffers from the fast recombination of charge carriers. Herein, we report mesoporous SiC nanofibers with in situ embedded graphitic carbon （SiC NFs-Cx） synthesized via a one-step carbothermal reduction between electrospun carbon nanofibers and Si powders. In the absence of a noble metal co-catalyst, the hydrogen evolution efficiency of SiC NFs-Cx is significantly improved under both simulated solar light （180.2 μmol.g-1.h-1） and visible light irradiation （31.0 ~amol-g-l-h-~） in high-pH solution. The efficient simultaneous separation of charge carriers plays a critical role in the high photocatalytic activity. The embedded carbon can swiftly transfer the photogenerated electrons and improve light absorption, whereas the additional hydroxyl anions （OH-） in high- pH solution can accelerate the trapping of holes. Our results demonstrate that the production of SiC NFs-Cx, which contains exclusively earth-abundant elements, scaled up, and is environmentally friendly, has great potential for practical applications. This work may provide a new pathway for designing stable, low- cost, high efficiency, and co-catalyst-free photocatalysts.
基金supported by the National Natural Science Foundation of China(2127303621177024)+1 种基金the National Basic Research Program of China(973 Program2014CB239303)~~
文摘Environmental pollution and energy deficiency represent major problems for the sustainability of the modern world. Photocatalysis has recently emerged as an effective and environmentally friendly technique to address some of these sustainability issues,although the key to the success of this approach is dependent on the photocatalysts themselves. Based on their attractive physic chemical properties,including their ultrahigh surface areas,homogeneous active sites and tunable functionality,metal-organic frameworks（MOFs） have become interesting platforms for the development of solar energy conversion devices. Furthermore,MOFs have recently been used in a wide variety of applications,including heterogeneous photocatalysis for pollutant degradation,organic transformations,hydrogen production and CO2 reduction. In this review,we have highlighted recent progress towards the application of MOFs in all of these areas. We have collected numerous reported examples of the use of MOFs in these areas,as well as providing some analysis of the key factors influencing the efficiency of these systems. Moreover,we have provided a detailed discussion of new strategies that have been developed for enhancing the photocatalytic activity of MOFs. Finally,we have provided an outlook for this area in terms of the future challenges and potential prospects for MOFs in photocatalysis.
基金financially supported by the Beijing Municipal High-Level Innovative Team Building Program (IDHT20180504)the National Natural Science Foundation of China (21805004, 21671011, 21872001 and 51801006)+3 种基金the Beijing Natural Science Foundation (KZ201710005002 and 2192005)the China Postdoctoral Science Foundation (2018M641133)the Beijing Postdoctoral Research Foundation (2018-ZZ-021)the Chaoyang District Postdoctoral Research Foundation, China (2018-ZZ-026)
文摘Photocatalytic N2 fixation involves a nitrogen reduction reaction on the surface of the photocatalyst to convert N2 into ammonia.Currently,the adsorption of N2 is the limiting step for the N2 reduction reaction on the surface of the catalyst.Based on the concept of photocatalytic water splitting,the photocatalytic efficiency can be greatly enhanced by introducing a co-catalyst.In this report,we proposed a new strategy,namely,the loading of a NiS co-catalyst on CdS nanorods for photocatalytic N2 fixation.Theoretical calculation results indicated that N2 was effectively adsorbed onto the NiS/CdS surface.Temperature programmed desorption studies confirmed that the N2 molecules preferred to adsorb onto the NiS/CdS surface.Linear sweep voltammetry results revealed that the overpotential of the N2 reduction reaction was reduced by loading NiS.Furthermore,transient photocurrent and electrochemical impedance spectroscopy indicated that the charge separation was enhanced by introducing NiS.Photocatalytic N2 fixation was carried out in the presence of the catalyst dispersed in water without any sacrificial agent.As a result,1.0 wt% NiS/CdS achieved an ammonia production rate of 2.8 and 1.7 mg L-1 for the first hour under full spectrum and visible light(λ>420 nm),respectively.The catalyst demonstrated apparent quantum efficiencies of 0.76%,0.39% and 0.09% at 420,475 and 520 nm,res pectively.This study provides a new method to promote the photocatalytic efficiency of N2 fixation.
基金supported by the National Natural Science Foundation of China(Nos.21777034 and 21606052)Natural Science Foundation of Guangdong Province(2020A1515010344)+4 种基金Science and Technology Innovation Project of Guangdong Province College Students(201811656019)Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(2019)Guangdong Basic and Applied Basic Research Foundation(2019A1515011249)Key Research Project of Natural Science of Guangdong Provincial Department of Education(2019KZDXM010)the program for Innovative Research Team of Guangdong University of Petrochemical Technology。
文摘Hydrogen production by photolysis of water by sunlight is an environmentally-friendly preparation technology for renewable energy.Graphitic carbon nitride(g-C3N4),despite with obvious catalytic effect,is still unsatisfactory for hydrogen production.In this work,phosphorus element is incorporated to tune g-C3N4's property through calcinating the mixture of g-C3N4 and Na H2PO2,sacrificial agent and co-catalyst also been supplied to help efficient photocatalytic hydrogen production.Phosphorus(P)doped g-C3N4 samples(PCN-S)were prepared,and their catalytic properties were studied.X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM)and ultraviolet diffuse reflection(UV-DRS)were used to study their structures and morphologies.The results show that the reaction rate of PCN-S is 318μmol·h^-1·g^-1,which is 2.98 times as high as pure carbon nitride nanosheets(CN)can do.Our study paves a new avenue,which is simple,environment-friendly and sustainable,to synthesize highly efficient P doping g-C3N4 nanosheets for solar energy conversion.
基金supported by the National Natural Science Foundation of China(Nos.51802171,52072197,and 52003136)the Outstanding Youth Foundation of Shandong Province,China(No.ZR2019JQ14)+2 种基金the Youth Innovation and Technology Foundation of Shandong Higher Education Institutions,China(No.2019KJC004)the Major Scientific and Technological Innovation Project(No.2019JZZY020405)Taishan Scholar Program,and the Major Basic Research Program of Natural Science Foundation of Shandong Province(No.ZR2020ZD09).
文摘Solar-light-driven CO_(2) reduction CO to CH_(4) and C2H6 is a complex process involving multiple elementary reactions and energy barriers.Therefore,achieving high CH_(4) activity and selectivity remains a significant challenge.Here,we integrate bifunctional Cu2O and Cu-MOF(MOF=metal-organic framework)core–shell co-catalysts(Cu2O@Cu-MOF)with semiconductor TiO_(2).Experiments and theoretical calculations demonstrate that Cu2O(Cu+facilitates charge separation)and Cu-MOF(Cu2+improves the CO_(2) adsorption and activation)in the core–shell structure have a synergistic effect on photocatalytic CO_(2) reduction,reducing the formation barrier of the key intermediate*COOH and*CHO.The photocatalyst exhibits high CH_(4) yield(366.0μmol·g^(-1)·h^(-1)),efficient electron transfer(3283μmol·g^(-1)·h^(-1))and hydrocarbon selectivity(95.5%),which represents the highest activity of Cu-MOF-based catalysts in photocatalytic CO_(2) reduction reaction.This work provides a strategy for designing efficient photocatalysts from the perspective of precise regulation of components.
基金partial financial support from NSFC(51372173,51002107,and21173159)NSFC for Distinguished Young Scholars(51025207)+3 种基金Research Climb Plan of ZJED(pd2013383)Opening Project of State Key Laboratory of High Performance Ceramics and Superfine Microstructure(SKL201409SIC)Xinmiao talent project of Zhejiang Province(2013R424060)College Students Research Project of Wenzhou University(14xk193)
文摘As BiVO4 is one of the most popular visible-light-responding photocatalysts, it has been widely used for visiblelight-driven water splitting and environmental purification. However, the typical photocatalytic activity of unmodified BiVO4 for the degradation of organic pollutants is still not impressive. To address this limitation, we studied Fe2O3-modified porous BiVO4 nanoplates. Compared with unmodified BiVO4, the Fe2O3-modified porous Bi VO4 nanoplates showed significantly enhanced photocatalytic activities in decomposing both dye and colorless pollutant models, such as rhodamine B(Rh B) and phenol,respectively. The pseudo-first-order reaction rate constants for the degradation of RhB and phenol on Fe2O3-modified BiVO4 porous nanoplates are 27 and 31 times larger than that of pristine Bi VO4, respectively. We also found that the Fe2O3 may act as an efficient non-precious metal co-catalyst, which is responsible for the excellent photocatalytic activity of Fe2O3/BiVO4.Graphical Abstract Fe2O3, as a cheap and efficient co-catalyst, could greatly enhance the photocatalytic activity of Bi VO4 porous nanoplates in decomposing organic pollutants.
基金financially supported by the Programs of Japan Science and Technology Agency:Promoting Individual Research to Nature the Seeds of Future Innovation and Organizing the Unique and Innovative Network,and Advanced Catalytic Transformation Program for Carbon Utilization
文摘Graphitic carbon nitride(g-C3N4)was synthesized by heating melamine and was then treated with sodium hydroxide solution under a hydrothermal condition to obtain g-C3N4 with a large specific surface area(HSSA).HSSA shows higher photocatalytic activity for decomposition of acetaldehyde than that of original g-C3N4.HSSA was modified with RuO2 as a co-catalyst by the impregnation method.HSSA loaded with 0.05 wt%RuO2 shows the highest photocatalytic activity for acetaldehyde decomposition under visible light(k=455 nm).
基金supported by the National Natural Science Foundation of China(Nos.22075193 and 22072101)the Natural Science Foundation of Jiangsu Province(Nos.BK20221239,BK20211306,and BK20220027)+1 种基金the Six Talent Peaks Project in Jiangsu Province(No.TD-XCL-006)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.
文摘Assembly of two-dimensional(2D)metal–organic layers(MOLs)based on the hard and soft acid–base theorem represents an exquisite strategy for the construction of photocatalytic platforms in virtue of the highly exposed active sites,much improved mass transport,and greatly elevated stability.Herein,nanocages composed of MOLs are produced for the first time through a cosolvent approach utilizing zirconium-based UiO-66-(OH)2 as the structural precursor.To endow the catalytic activity for CO_(2) conversion,single atomic Co^(2+)sites are appended to the Zr-oxo nodes of the MOL cages,demonstrating a remarkable CO yield of 7.74 mmol·g^(-1)·h^(-1) and operational stability of 97.1%product retention after five repeated cycles.Such an outstanding photocatalytic performance is mainly attributed to the unique nanocage morphology comprising enormous 2D nanosheets for augmented Co^(2+)exposure and the abundant surface hydroxyl groups for local CO_(2) enrichment.This work underlines the tailoring of both metal–organic framework(MOF)morphology and functionality to boost the turnover rate of photocatalytic CO_(2) reduction reaction(CO_(2)RR).
文摘Modification of nickel sulfide cocatalysts is considered to be a promising approach for efficient enhancement of the photocatalytic hydrogen production performance of g-C3N4.Providing more NiS cocatalyst to function as active sites of g-C3N4 is still highly desirable.To realize this goal,in this work,a facile sulfur-mediated photodeposition approach was developed.Specifically,photogenerated electrons excited by visible light reduce the S molecules absorbed on g-C3N4 surface to S^2‒,and subsequently NiS cocatalyst is formed in situ on the g-C3N4 surface by a combination of Ni2+and S2‒due to their small solubility product constant(Ksp=3.2×10^‒19).This approach has several advantages.The NiS cocatalyst is clearly in situ deposited on the photogenerated electron transfer sites of g-C3N4,and thus provides more active sites for H2 production.In addition,this method utilizes solar energy with mild reaction conditions at room temperature.Consequently,the synthesized NiS/g-C3N4 photocatalyst achieves excellent hydrogen generation performance with the performance of the optimal sample(244μmol h^‒1 g^‒1)close to that of 1 wt%Pt/g-C3N4(316μmol h^‒1 g^‒1,a well-known excellent photocatalyst).More importantly,the present sulfur-mediated photodeposition route is versatile and facile and can be used to deposit various metal sulfides such as CoSx,CuSx and AgSx on the g-C3N4 surface,and all the resulting metal sulfide-modified g-C3N4 photocatalysts exhibit improved H2-production performance.Our study offers a novel insight for the synthesis of high-efficiency photocatalysts.
文摘Photocatalytic degradation and hydrogen production using solar energy through semiconductor photocatalysts are deemed to be a powerful approach for solving environmental and energy crisis.However,the biggest challenge in photocatalysis is the efficient separation of photo-induced carriers.To this end,we report that the mesoporous TiO_(2)nanoparticles are anchored on highly conductive Ti_(3)C_(2)MXene co-catalyst by electrostatic self-assembly strategy.The constructed mesoporous TiO_(2)/Ti_(3)C_(2)composites display that the mesoporous TiO_(2)nanoparticles are uniformly distributed on the surface of layer structured Ti_(3)C_(2)nanosheets.More importantly,the as-obtained mesoporous TiO_(2)/Ti_(3)C_(2)composites reveal the significantly enhanced light absorption performance,photo-induced carriers separation and transfer ability,thus boosting the photocatalytic activity.The photocatalytic methyl orange degradation efficiency of mesoporous TiO_(2)/Ti_(3)C_(2)composite with an optimized Ti_(3)C_(2)content(3 wt%)can reach 99.6%within 40 min.The capture experiments of active species confirm that the·O_(2)-and·OH play major role in photocatalytic degradation process.Furthermore,the optimized mesoporous TiO_(2)/Ti_(3)C_(2)composite also shows an excellent photocatalytic H2 production rate of 218.85μmol g^(-1)h^(-1),resulting in a 5.6 times activity as compared with the pristine mesoporous TiO_(2)nanoparticles.This study demonstrates that the MXene family materials can be applied as highly efficient noble-metal-free co-catalysts in the field of photocatalysis.
