The application of photocatalytic technology in algae killing is limited by the non-floatability and difficulty in recycling of the photocatalysts.Loading photocatalyst on magnetic or floatable carriers is the most po...The application of photocatalytic technology in algae killing is limited by the non-floatability and difficulty in recycling of the photocatalysts.Loading photocatalyst on magnetic or floatable carriers is the most popular method for overcoming the above inadequacies.In this work,a CdZnS/TiO_(2) membrane photocatalyst with adjustable suspended depth(include floating)and flexible assembly is designed,which is less prone to dislodgement due to in situ synthesis and has a wider range of applicability than previously reported photocatalysts.The photocatalytic removal of Microcystis aeruginosa revealed that the suspended depth and distribution format of the CdZnS/TiO_(2) membrane photocatalysts have striking effects on the photocatalytic removal performance of Microcystis aeruginosa,the photocatalytic removal efficiency of CdZnS/TiO_(2)-2 membrane photocatalysts for Microcystis aeruginosa could reach to 98.6%in 60 min when the photocatalysts assembled in the form of 3×3 arrays suspended at a depth of 2 cm from the liquid surface.A tiny amount of TiO_(2) loading allows the formation of Z-Scheme heterojunction,resulting in accelerating the separation efficiency of photogenerated carriers,preserving the photogenerated electrons and holes with stronger reduction and oxidation ability and inhabiting the photo-corrosion of CdZnS.展开更多
Storing solar energy in battery systems is crucial to achieving a green and sustainable society.However,the efficient development of photo-enhanced zinc-air batteries(ZABs)is limited by the rapid recombination of phot...Storing solar energy in battery systems is crucial to achieving a green and sustainable society.However,the efficient development of photo-enhanced zinc-air batteries(ZABs)is limited by the rapid recombination of photogenerated carriers on the photocathode.In this work,the visible-light-driven CoS_(2)/CuS@CNT-C_(3)N_(4)photocatalyst with unique petal-like layer structure was designed and developed,which can be used as air electrode for visible-light-driven ZABs.The superior performance of ZABs assembled by CoS_(2)/CuS@CNT-C_(3)N_(4)was mainly attributed to the successful construction of Schottky heterojunction between g-C_(3)N_(4)and carbon nanotubes(CNTs),which accelerates the transfer of electrons from g-C_(3)N_(4)to CoS_(2)/CuS cocatalysts,improves the carrier separation ability,and extends the carrier lifetime.Thereinto,the visible-driven ZABs assembled by CoS_(2)/CuS@CNT-C_(3)N_(4)photocatalyst has a power density of 588.90 mW cm^(-2) and a charge-discharge cycle of 643 h under visible light irradiation,which is the highest performance ever reported for photo-enhanced ZABs.More importantly,the charge-discharge voltage drop of ZABs was only 0.54 V under visible light irradiation,which is significantly lower than the voltage drop(0.94 V)in the dark.This study provides a new idea for designing efficient and stable visible-light-driven ZABs cathode catalysts.展开更多
Two-dimensional(2D)heterojunctions are promising photocatalysts for hydrogen production due to their unique ability to efficiently convert solar energy to green fuels.In this work,an S-scheme 2D/2D FTiO_(2)/CdS hetero...Two-dimensional(2D)heterojunctions are promising photocatalysts for hydrogen production due to their unique ability to efficiently convert solar energy to green fuels.In this work,an S-scheme 2D/2D FTiO_(2)/CdS heterostructure was designed and synthesized via a facile hydrothermal method.The hydrogen evolution rate of optimal F-TiO_(2)/CdS photocatalyst irradiated with simulated sunlight reached to 1.7 mmol g^(−1) h^(−1),which was about 7 times that of pristine CdS nanosheets,1.5 times that of TiO_(2) nanoparticles composited with CdS nanosheets,and the apparent quantum efficiency at 420 nm was 4.3%.The insitu Kelvin probe force microscopy results showed that the built-in electric field strength(BIEF)of 2D/2D F-TiO_(2)/CdS is about 6.2×10^(3) V cm^(−1) under the dark condition,which is about 2.3 times that of TiO_(2) nanoparticles composited with CdS nanosheets.Moreover,in-situ electron paramagnetic resonance results showed that the valence band position of F-TiO_(2) is more positive and showed a clear signal peak,suggesting that F-TiO_(2) could generate more hydroxyl radicals.When F-TiO_(2) contacts with CdS,the signals of both radicals are significantly enhanced,indicating that the reducing ability of CdS and the oxidizing ability of F-TiO_(2) are well preserved.These results verify that S-scheme 2D/2D F-TiO_(2)/CdS processes stronger BIEF,which could effectively enhance the photocatalytic hydrogen production activity.展开更多
The present levels of CO_(2)emission in the atmosphere require the development of technologies to achieve carbon neutrality using inexpensive processes.Conversion of CO_(2)into cyclic carbonates is one of the solution...The present levels of CO_(2)emission in the atmosphere require the development of technologies to achieve carbon neutrality using inexpensive processes.Conversion of CO_(2)into cyclic carbonates is one of the solutions to this problem.Here,we synthesized a ZnV_(2)O_(6)/Bi_(2)WO_(6)nanocomposite and catalyzed the cycloaddition of CO_(2)to epoxides for the green synthesis of cyclic carbonates under visible light irradiation.The present nanocomposite photocatalyst exhibited up to 96%yield of cyclic carbonates.The photocatalyst was found to be efficient for photocatalytic cycloaddition reactions,and the recovered photocatalyst showed stability in up to five consecutive photocatalytic experiments.The current methodology of cyclic carbonate production is a significant step toward the mitigation of atmospheric CO_(2)and can work well with the development of nanocomposite photocatalysts.展开更多
Hydrogen peroxide(H_(2)O_(2)),an environmentally friendly chemical with high value,is extensively used in industrial production and daily life.However,the traditional anthraquinone method for H_(2)O_(2) production is ...Hydrogen peroxide(H_(2)O_(2)),an environmentally friendly chemical with high value,is extensively used in industrial production and daily life.However,the traditional anthraquinone method for H_(2)O_(2) production is associated with a highly energy-consuming and heavily polluting process.Solor-driven photocatalytic evolution of H_(2)O_(2) is a promising,eco-friendly,and energy-efficient strategy that holds great potential to substitute the traditional approach.Here,a ternary photocatalyst,NiS/CdS/Halloysite nanotubes(NiS/CdS/HNTs)is designed and prepared with an earth-abundant clay mineral HNTs as the support and NiS as a co-catalyst.The pivotal roles of HNTs and NiS in the photocatalytic process are elucidated by experiments and theoretical calculations.HNTs serve as the carrier,which allows CdS to be uniformly dispersed onto its surface as small particles,increasing effective contact with H_(2)O and O_(2) for H_(2)O_(2) formation.Simultaneously,it resulted in the formation of a Schottky junction between NiS and CdS,which not only favors photogenerated charges separating efficiently but also provides a unidirectional path to transfer electrons.Consequently,the optimized NiS/CdS/HNTs composite demonstrates an H_(2)O_(2) evolution rate of 380.5μmol·g^(-1)·h^(-1) without adding any sacrificial agent or extra O_(2),nearly 5.0 times that of pure CdS.This work suggests a feasible idea for designing and developing highly active and low-cost solar energy catalytic composite materials.展开更多
In this work,we report a fabrication of recyclable iron oxide decorated MoS_(2)nanosheets via a facile liq-uid exfoliation approach and solvothermal reaction for visible-light photodegradation of tetracycline.The prep...In this work,we report a fabrication of recyclable iron oxide decorated MoS_(2)nanosheets via a facile liq-uid exfoliation approach and solvothermal reaction for visible-light photodegradation of tetracycline.The prepared Fe_(3)O_(4)-MoS_(2)was characterized by X-ray diffraction,transmission electron microscopy,X-ray photoelectron spectros-copy,Raman spectroscopy,magnetic hysteresis,and nitrogen adsorption-desorption isotherms.Experimental results indicate that,successful attachment of Fe_(3)O_(4)nanoparticles to MoS_(2)sheets has been achieved.The enhanced surface area of Fe_(3)O_(4)-MoS_(2)induced high rates of adsorption and the adsorbed tetracycline was degraded to 90%after 150 min of visible exposure,which is better than that from pure MoS_(2).The introduction of Fe_(3)O_(4)not only enhances the photo-catalytic performance of Fe_(3)O_(4)-MoS_(2),but also enables its convenient recovery from water by an external magnetic field.Furthermore,both the photocatalytic activity and composite phase of Fe_(3)O_(4)-MoS_(2)were well-retained over cy-cles.Owing to its efficient photocatalytic activity,good stability and magnetic recyclability,the Fe_(3)O_(4)-MoS_(2)nano-composite is considered to be a promising photocatalyst for wastewater treatment.展开更多
Hydrogen peroxide(H_(2)O_(2)) has been recognized as a green and nonpolluting multifunctional oxidant with extensive applications in environmental protection,metal etching,textile printing and dyeing,chemical synthesi...Hydrogen peroxide(H_(2)O_(2)) has been recognized as a green and nonpolluting multifunctional oxidant with extensive applications in environmental protection,metal etching,textile printing and dyeing,chemical synthesis and food processing.However,over 90 % of industrial H_(2)O_(2) is currently produced through the multi-step anthraquinone oxidation process,which suffers from a process with some drawbacks such as complex,high-energy consumption,and toxic byproducts emissions.Compared to the traditional anthraquinone method,artificial photosynthesis of H_(2)O_(2) using semiconductor photocatalysts has emerged as a sustainable alternative due to its use of water and O_(2) as the clean reactants and sole energy as the driving force.In recent years,metal-free photocatalysts mainly including covalent organic frameworks(COFs),covalent triazine frameworks(CTFs) and carbon nitrile(g-C_(3)N_(4)) have garnered significant interest due to their superior thermal and chemical stability,diverse synthesis methods,tunable functionality,light weight nature and non-toxicity.These materials also exhibit adjustable band structure and unique photoelectric properties.Sustainable efforts have been made to advance metal-free photocatalysts for artificial photosynthesis of H_(2)O_(2),however,a comprehensive summary of current research status on metalfree-based photocatalytic overall H_(2)O_(2) production remain scarce.This review outlines recent process in overall H_(2)O_(2) photosynthesis based on metal-free photocatalysts.First,we introduced the fundamental concepts of photocatalytic overall H_(2)O_(2) production.Then,we analyze representative studies on photocatalytic overall H_(2)O_(2) synthesis using metal-free materials.Finally,we discuss the challenges and future perspectives in this field to guide the design and synthesis of metal-free systems for H_(2)O_(2) generation.展开更多
A visible-light photocatalyst was prepared by calcination of the hydrolysis product of Ti(SO_4)_2 with ammonia as precipitator. The color of this photocatalyst was vivid yellow. It could absorb light under 550 nm wave...A visible-light photocatalyst was prepared by calcination of the hydrolysis product of Ti(SO_4)_2 with ammonia as precipitator. The color of this photocatalyst was vivid yellow. It could absorb light under 550 nm wavelength. The crystal structure of anatase was characterized by XRD. The structure analysis result of X-ray fluorescence(XRF) shows that doped-nitrogen was presented in the sample. The photocatalytic activities were evaluated using methyl orange and phenol as model pollutants. The photocatalytic activities of samples were increasing gradually with calcination temperature from 400℃ to 700℃ under UV irradiation. It can be seen that the degradation of methyl orange follows zero-order kinetics. However, the calcination temperatures have no significant influence on the degradation of phenol under sunlight. The N-doped catalyst shows higher activity than the bare one under solar irradiation.展开更多
Bismuth tungstate(Bi_(2)WO_(6))has become a research hotspot due to its potential in photocatalytic energy conversion and environmental purification.Nevertheless,the limited light absorption and fast recombination of ...Bismuth tungstate(Bi_(2)WO_(6))has become a research hotspot due to its potential in photocatalytic energy conversion and environmental purification.Nevertheless,the limited light absorption and fast recombination of photogenerated carriers hinder the further improvement of the photocatalytic performance of Bi_(2)WO_(6).Herein,we provide a systematic review for the recent advances on Bi_(2)WO_(6)‐based photocatalysts.It starts with the crystal structure,optical properties and photocatalytic fundamentals of Bi_(2)WO_(6).Then,we focus on the modification strategies of Bi_(2)WO_(6)based on morphology control,atomic modulation and composite fabrication for diverse photocatalytic applications,such as organic synthesis,water splitting,CO2 reduction,water treatment,air purification,bacterial inactivation,etc.Finally,some current challenges and future development prospects are proposed.We expect that this review can provide a useful reference and guidance for the development of efficient Bi_(2)WO_(6)photocatalysts.展开更多
TiO2‐based Z‐scheme photocatalysts have attracted considerable attention because of the low recombination rate of their photogenerated electron–hole pairs and their high photocatalytic efficiency.In this review,the...TiO2‐based Z‐scheme photocatalysts have attracted considerable attention because of the low recombination rate of their photogenerated electron–hole pairs and their high photocatalytic efficiency.In this review,the reaction mechanism of Z‐scheme photocatalysts,recent research progress in the application of TiO2‐based Z‐scheme photocatalysts,and improved methods for photocatalytic performance enhancement are explored.Their applications,including water splitting,CO2reduction,decomposition of volatile organic compounds,and degradation of organic pollutants,are also described.The main factors affecting the photocatalytic performance of TiO2‐based Z‐scheme photocatalysts,such as pH,conductive medium,cocatalyst,architecture,and mass ratio,are discussed.Concluding remarks are presented,and some suggestions for the future development of TiO2‐based Z‐scheme photocatalysts are highlighted.展开更多
Although the traditional Fenton reaction is considered an effective strategy for solving problems caused by environmental pollution,construction of an efficient photocatalytic system by coordinating the Fenton reactio...Although the traditional Fenton reaction is considered an effective strategy for solving problems caused by environmental pollution,construction of an efficient photocatalytic system by coordinating the Fenton reaction is challenging.In this study,2D/2D step-schemeα-Fe2O3/Bi2WO6(FO/BWO)heterostructure photo-Fenton catalysts were successfully fabricated by a facile hydrothermal method.The as-prepared materials were characterized by XRD,FT-IR,TEM,XPS,UV-vis DRS,PL,I-t,EIS,and BET analyses.Under visible light irradiation,FO/BWO exhibited remarkably high and stable photo-Fenton catalytic activity for the degradation of methyl blue(MB)at low concentrations of H2O2.It was noted that FO/BWO(0.5)displayed a significantly enhanced photo-Fenton catalytic activity,which was 11.06 and 3.29 times those of FO nanosheets and BWO nanosheets,respectively.The notably improved photo-Fenton catalytic activity of FO/BWO was mainly due to the combination of H2O2 and FO under light illumination and the presence of the 2D/2D S-scheme heterostructure,with the large contact surface,abundant active sites,and efficient separation rate of photogenerated carriers playing contributory roles.Additionally,a possible catalytic mechanism for the FO/BWO composite was preliminarily proposed via active species trapping experiments.In summary,this study provided new insights into the synthesis of an effectively heterogeneous 2D/2D S-scheme photo-Fenton catalyst for degradation of organic pollutants in wastewater.展开更多
N-F-codoped TiO2 （NFTO） photocatalysts were synthesized by a simple sol-gel process with tetrabutyl titanate （Ti（OBu）4 ） as the precursor of TiO 2 and ammonium fluoride （NH4 F） as the source of N and F.The syn...N-F-codoped TiO2 （NFTO） photocatalysts were synthesized by a simple sol-gel process with tetrabutyl titanate （Ti（OBu）4 ） as the precursor of TiO 2 and ammonium fluoride （NH4 F） as the source of N and F.The synthesized photocatalysts were investigated by X- ray diffraction （XRD）,X-ray photoelectron spectroscopy （XPS）,ultraviolet-visible diffuse reflectance spectroscopy （UV-Vis DRS） and photodegradation reaction tests of 4-chlorophenol under visible light irradiation to understand the relationship between the structure of NFTO catalyst and corresponding photocatalytic activity.The crystal phase and particle size of catalysts were found to be largely affected by the calcination temperature.In addition,N-F-codoping could inhibit phase transition of TiO2 from anatase to rutile.The presence of N and F atoms in the lattice of TiO2 is responsible for the visible light catalytic activity.In UV-Vis DRS tests,the spectrum of NFTO exhibited red shift compared with Degussa P25 and the band gap was reduced to around 2.92 eV.Under optimal calcination temperature and dopant concentration conditions,the NFTO photocatalyst exhibited the highest activity in the photodegradation reaction tests of 4-chlorophenol under visible light irradiation with a degradation rate of 75.84%.Besides,the 5-recycle test showed that NFTO photocatalyst could be reused and its activity kept stable under visible light irradiation.展开更多
The photocatalytic properties of CeO2-Nb2O5 photocatalysts in heterogeneous photocatalysis(under ultraviolet and visible radiation)and in Fenton-like process were reported.Methylene blue dye(MB)and phenol(Ph)were used...The photocatalytic properties of CeO2-Nb2O5 photocatalysts in heterogeneous photocatalysis(under ultraviolet and visible radiation)and in Fenton-like process were reported.Methylene blue dye(MB)and phenol(Ph)were used as models of pollutant molecules for these reactions,and the photocatalysts were characterized by X-ray diffraction(XRD),diffuse reflectance spectroscopy(DRS),scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy(EDX)and thermally stimulated luminescence(TL).The results indicated that the addition of CeO2(0.3 wt%,1.0 wt%and 2.0 wt%)to Nb2O5 sensitized the resultant materials,increasing light absorption in the visible region.However,there is a suitable formulation of CeO2-Nb2O5 photocatalysts to improve each photocatalytic process.In heterogeneous photocatalysis,the addition of small CeO2 quantities to Nb2O5 was enough to improve the photocatalytic activity of CeO2-Nb2O5 photocatalysts(The best composition reported was CeO20.3 wt%.).The effectiveness of the catalyst was explained by the decrease in the number of trapping and luminescence centers in the conduction band of the material after the addition of CeO2 to Nb2O5,but a large amount of CeO2 decreased the number of trapping,luminescent and active centers to a large extent.Contrarily,in a Fenton-like process,the addition of CeO2 to Nb2O5 was favorable in all the proportions studied.(The best composition was 2.0 wt%CeO2.)In this case,the effectiveness was explained by the influence of the adsorption process(adsorption-triggered process),and the interactions between H2 O2 and Ce3+of the CeO2 in each photocatalyst thus formed surface peroxide species O22-,which induced the removal of the organic molecules under visible light.展开更多
Polyaniline （PAn） sensitized nanocrystalline TiO2 composites （TiO2/PAn） were successfully prepared and used as an efficient photocatalyst for the degradation of dye methylene blue （MB）. The results showed that P...Polyaniline （PAn） sensitized nanocrystalline TiO2 composites （TiO2/PAn） were successfully prepared and used as an efficient photocatalyst for the degradation of dye methylene blue （MB）. The results showed that PAn was able to sensitize TiO2 efficiently and the composite photocatalyst could be activated by absorbing both the ultraviolet and visible light （λ： 190 ～ 800 nm）, whereas pure TiO2 absorbed ultraviolet light only （λ 〈 380 nm）. Under the irradiation of natural light, MB could be degraded more efficiently on the TiO2/PAn composites than on the TiO2 Furthermore, it could be easily separated from the solution by simple sedimentation.展开更多
基金financially supported by the Natural Science Foundation of ShanDong(Nos.ZR2023QD152 and ZR2021MD002).
文摘The application of photocatalytic technology in algae killing is limited by the non-floatability and difficulty in recycling of the photocatalysts.Loading photocatalyst on magnetic or floatable carriers is the most popular method for overcoming the above inadequacies.In this work,a CdZnS/TiO_(2) membrane photocatalyst with adjustable suspended depth(include floating)and flexible assembly is designed,which is less prone to dislodgement due to in situ synthesis and has a wider range of applicability than previously reported photocatalysts.The photocatalytic removal of Microcystis aeruginosa revealed that the suspended depth and distribution format of the CdZnS/TiO_(2) membrane photocatalysts have striking effects on the photocatalytic removal performance of Microcystis aeruginosa,the photocatalytic removal efficiency of CdZnS/TiO_(2)-2 membrane photocatalysts for Microcystis aeruginosa could reach to 98.6%in 60 min when the photocatalysts assembled in the form of 3×3 arrays suspended at a depth of 2 cm from the liquid surface.A tiny amount of TiO_(2) loading allows the formation of Z-Scheme heterojunction,resulting in accelerating the separation efficiency of photogenerated carriers,preserving the photogenerated electrons and holes with stronger reduction and oxidation ability and inhabiting the photo-corrosion of CdZnS.
文摘Storing solar energy in battery systems is crucial to achieving a green and sustainable society.However,the efficient development of photo-enhanced zinc-air batteries(ZABs)is limited by the rapid recombination of photogenerated carriers on the photocathode.In this work,the visible-light-driven CoS_(2)/CuS@CNT-C_(3)N_(4)photocatalyst with unique petal-like layer structure was designed and developed,which can be used as air electrode for visible-light-driven ZABs.The superior performance of ZABs assembled by CoS_(2)/CuS@CNT-C_(3)N_(4)was mainly attributed to the successful construction of Schottky heterojunction between g-C_(3)N_(4)and carbon nanotubes(CNTs),which accelerates the transfer of electrons from g-C_(3)N_(4)to CoS_(2)/CuS cocatalysts,improves the carrier separation ability,and extends the carrier lifetime.Thereinto,the visible-driven ZABs assembled by CoS_(2)/CuS@CNT-C_(3)N_(4)photocatalyst has a power density of 588.90 mW cm^(-2) and a charge-discharge cycle of 643 h under visible light irradiation,which is the highest performance ever reported for photo-enhanced ZABs.More importantly,the charge-discharge voltage drop of ZABs was only 0.54 V under visible light irradiation,which is significantly lower than the voltage drop(0.94 V)in the dark.This study provides a new idea for designing efficient and stable visible-light-driven ZABs cathode catalysts.
基金supported by the National Natural Science Foundation of China(No.22378372).
文摘Two-dimensional(2D)heterojunctions are promising photocatalysts for hydrogen production due to their unique ability to efficiently convert solar energy to green fuels.In this work,an S-scheme 2D/2D FTiO_(2)/CdS heterostructure was designed and synthesized via a facile hydrothermal method.The hydrogen evolution rate of optimal F-TiO_(2)/CdS photocatalyst irradiated with simulated sunlight reached to 1.7 mmol g^(−1) h^(−1),which was about 7 times that of pristine CdS nanosheets,1.5 times that of TiO_(2) nanoparticles composited with CdS nanosheets,and the apparent quantum efficiency at 420 nm was 4.3%.The insitu Kelvin probe force microscopy results showed that the built-in electric field strength(BIEF)of 2D/2D F-TiO_(2)/CdS is about 6.2×10^(3) V cm^(−1) under the dark condition,which is about 2.3 times that of TiO_(2) nanoparticles composited with CdS nanosheets.Moreover,in-situ electron paramagnetic resonance results showed that the valence band position of F-TiO_(2) is more positive and showed a clear signal peak,suggesting that F-TiO_(2) could generate more hydroxyl radicals.When F-TiO_(2) contacts with CdS,the signals of both radicals are significantly enhanced,indicating that the reducing ability of CdS and the oxidizing ability of F-TiO_(2) are well preserved.These results verify that S-scheme 2D/2D F-TiO_(2)/CdS processes stronger BIEF,which could effectively enhance the photocatalytic hydrogen production activity.
基金sponsored in part by the National Natural Science Foundation of China(No.21477167)the Science and Technology Research Plan Program of Henan Province(Nos.222102320328,232102210075,232102320137)the Key Science Research Program Foundation of High Education Schools of Henan Province(No.23B610010).
文摘The present levels of CO_(2)emission in the atmosphere require the development of technologies to achieve carbon neutrality using inexpensive processes.Conversion of CO_(2)into cyclic carbonates is one of the solutions to this problem.Here,we synthesized a ZnV_(2)O_(6)/Bi_(2)WO_(6)nanocomposite and catalyzed the cycloaddition of CO_(2)to epoxides for the green synthesis of cyclic carbonates under visible light irradiation.The present nanocomposite photocatalyst exhibited up to 96%yield of cyclic carbonates.The photocatalyst was found to be efficient for photocatalytic cycloaddition reactions,and the recovered photocatalyst showed stability in up to five consecutive photocatalytic experiments.The current methodology of cyclic carbonate production is a significant step toward the mitigation of atmospheric CO_(2)and can work well with the development of nanocomposite photocatalysts.
文摘Hydrogen peroxide(H_(2)O_(2)),an environmentally friendly chemical with high value,is extensively used in industrial production and daily life.However,the traditional anthraquinone method for H_(2)O_(2) production is associated with a highly energy-consuming and heavily polluting process.Solor-driven photocatalytic evolution of H_(2)O_(2) is a promising,eco-friendly,and energy-efficient strategy that holds great potential to substitute the traditional approach.Here,a ternary photocatalyst,NiS/CdS/Halloysite nanotubes(NiS/CdS/HNTs)is designed and prepared with an earth-abundant clay mineral HNTs as the support and NiS as a co-catalyst.The pivotal roles of HNTs and NiS in the photocatalytic process are elucidated by experiments and theoretical calculations.HNTs serve as the carrier,which allows CdS to be uniformly dispersed onto its surface as small particles,increasing effective contact with H_(2)O and O_(2) for H_(2)O_(2) formation.Simultaneously,it resulted in the formation of a Schottky junction between NiS and CdS,which not only favors photogenerated charges separating efficiently but also provides a unidirectional path to transfer electrons.Consequently,the optimized NiS/CdS/HNTs composite demonstrates an H_(2)O_(2) evolution rate of 380.5μmol·g^(-1)·h^(-1) without adding any sacrificial agent or extra O_(2),nearly 5.0 times that of pure CdS.This work suggests a feasible idea for designing and developing highly active and low-cost solar energy catalytic composite materials.
文摘In this work,we report a fabrication of recyclable iron oxide decorated MoS_(2)nanosheets via a facile liq-uid exfoliation approach and solvothermal reaction for visible-light photodegradation of tetracycline.The prepared Fe_(3)O_(4)-MoS_(2)was characterized by X-ray diffraction,transmission electron microscopy,X-ray photoelectron spectros-copy,Raman spectroscopy,magnetic hysteresis,and nitrogen adsorption-desorption isotherms.Experimental results indicate that,successful attachment of Fe_(3)O_(4)nanoparticles to MoS_(2)sheets has been achieved.The enhanced surface area of Fe_(3)O_(4)-MoS_(2)induced high rates of adsorption and the adsorbed tetracycline was degraded to 90%after 150 min of visible exposure,which is better than that from pure MoS_(2).The introduction of Fe_(3)O_(4)not only enhances the photo-catalytic performance of Fe_(3)O_(4)-MoS_(2),but also enables its convenient recovery from water by an external magnetic field.Furthermore,both the photocatalytic activity and composite phase of Fe_(3)O_(4)-MoS_(2)were well-retained over cy-cles.Owing to its efficient photocatalytic activity,good stability and magnetic recyclability,the Fe_(3)O_(4)-MoS_(2)nano-composite is considered to be a promising photocatalyst for wastewater treatment.
基金supported by the National Natural Science Foundation of China (No.22409038,52473221)Zhejiang Province Postdoctoral Science Foundation (No.ZJ2024021)+2 种基金Hubei Provincial Natural Science Foundation of China (Nos.2024DJC032,2025AFB889)Key Project of Science and Technology Research of Hubei Provincial Department of Education (Nos.D20232701,D20232702)the research grant funded by the Research,Development,and Innovation Authority (RDIA)-Kingdom of Saudi Arabia (No.12615-iu-2023-IU-R-2-1-EI-)。
文摘Hydrogen peroxide(H_(2)O_(2)) has been recognized as a green and nonpolluting multifunctional oxidant with extensive applications in environmental protection,metal etching,textile printing and dyeing,chemical synthesis and food processing.However,over 90 % of industrial H_(2)O_(2) is currently produced through the multi-step anthraquinone oxidation process,which suffers from a process with some drawbacks such as complex,high-energy consumption,and toxic byproducts emissions.Compared to the traditional anthraquinone method,artificial photosynthesis of H_(2)O_(2) using semiconductor photocatalysts has emerged as a sustainable alternative due to its use of water and O_(2) as the clean reactants and sole energy as the driving force.In recent years,metal-free photocatalysts mainly including covalent organic frameworks(COFs),covalent triazine frameworks(CTFs) and carbon nitrile(g-C_(3)N_(4)) have garnered significant interest due to their superior thermal and chemical stability,diverse synthesis methods,tunable functionality,light weight nature and non-toxicity.These materials also exhibit adjustable band structure and unique photoelectric properties.Sustainable efforts have been made to advance metal-free photocatalysts for artificial photosynthesis of H_(2)O_(2),however,a comprehensive summary of current research status on metalfree-based photocatalytic overall H_(2)O_(2) production remain scarce.This review outlines recent process in overall H_(2)O_(2) photosynthesis based on metal-free photocatalysts.First,we introduced the fundamental concepts of photocatalytic overall H_(2)O_(2) production.Then,we analyze representative studies on photocatalytic overall H_(2)O_(2) synthesis using metal-free materials.Finally,we discuss the challenges and future perspectives in this field to guide the design and synthesis of metal-free systems for H_(2)O_(2) generation.
文摘A visible-light photocatalyst was prepared by calcination of the hydrolysis product of Ti(SO_4)_2 with ammonia as precipitator. The color of this photocatalyst was vivid yellow. It could absorb light under 550 nm wavelength. The crystal structure of anatase was characterized by XRD. The structure analysis result of X-ray fluorescence(XRF) shows that doped-nitrogen was presented in the sample. The photocatalytic activities were evaluated using methyl orange and phenol as model pollutants. The photocatalytic activities of samples were increasing gradually with calcination temperature from 400℃ to 700℃ under UV irradiation. It can be seen that the degradation of methyl orange follows zero-order kinetics. However, the calcination temperatures have no significant influence on the degradation of phenol under sunlight. The N-doped catalyst shows higher activity than the bare one under solar irradiation.
文摘Bismuth tungstate(Bi_(2)WO_(6))has become a research hotspot due to its potential in photocatalytic energy conversion and environmental purification.Nevertheless,the limited light absorption and fast recombination of photogenerated carriers hinder the further improvement of the photocatalytic performance of Bi_(2)WO_(6).Herein,we provide a systematic review for the recent advances on Bi_(2)WO_(6)‐based photocatalysts.It starts with the crystal structure,optical properties and photocatalytic fundamentals of Bi_(2)WO_(6).Then,we focus on the modification strategies of Bi_(2)WO_(6)based on morphology control,atomic modulation and composite fabrication for diverse photocatalytic applications,such as organic synthesis,water splitting,CO2 reduction,water treatment,air purification,bacterial inactivation,etc.Finally,some current challenges and future development prospects are proposed.We expect that this review can provide a useful reference and guidance for the development of efficient Bi_(2)WO_(6)photocatalysts.
基金supported by the National Natural Science Foundation of China(51602207,21433007,51320105001,21573170)the Self-determined and Innovative Research Funds of SKLWUT(2017-ZD-4,2016-KF-17)the Natural Science Foundation of Hubei Province of China(2015CFA001)~~
文摘TiO2‐based Z‐scheme photocatalysts have attracted considerable attention because of the low recombination rate of their photogenerated electron–hole pairs and their high photocatalytic efficiency.In this review,the reaction mechanism of Z‐scheme photocatalysts,recent research progress in the application of TiO2‐based Z‐scheme photocatalysts,and improved methods for photocatalytic performance enhancement are explored.Their applications,including water splitting,CO2reduction,decomposition of volatile organic compounds,and degradation of organic pollutants,are also described.The main factors affecting the photocatalytic performance of TiO2‐based Z‐scheme photocatalysts,such as pH,conductive medium,cocatalyst,architecture,and mass ratio,are discussed.Concluding remarks are presented,and some suggestions for the future development of TiO2‐based Z‐scheme photocatalysts are highlighted.
文摘Although the traditional Fenton reaction is considered an effective strategy for solving problems caused by environmental pollution,construction of an efficient photocatalytic system by coordinating the Fenton reaction is challenging.In this study,2D/2D step-schemeα-Fe2O3/Bi2WO6(FO/BWO)heterostructure photo-Fenton catalysts were successfully fabricated by a facile hydrothermal method.The as-prepared materials were characterized by XRD,FT-IR,TEM,XPS,UV-vis DRS,PL,I-t,EIS,and BET analyses.Under visible light irradiation,FO/BWO exhibited remarkably high and stable photo-Fenton catalytic activity for the degradation of methyl blue(MB)at low concentrations of H2O2.It was noted that FO/BWO(0.5)displayed a significantly enhanced photo-Fenton catalytic activity,which was 11.06 and 3.29 times those of FO nanosheets and BWO nanosheets,respectively.The notably improved photo-Fenton catalytic activity of FO/BWO was mainly due to the combination of H2O2 and FO under light illumination and the presence of the 2D/2D S-scheme heterostructure,with the large contact surface,abundant active sites,and efficient separation rate of photogenerated carriers playing contributory roles.Additionally,a possible catalytic mechanism for the FO/BWO composite was preliminarily proposed via active species trapping experiments.In summary,this study provided new insights into the synthesis of an effectively heterogeneous 2D/2D S-scheme photo-Fenton catalyst for degradation of organic pollutants in wastewater.
基金supported by the Scienceand Technology Project of Education Commission of Chongqing of China(No.KJ110709)the Key Science Project of Ministry of Education of China(No.2008119)+1 种基金the Colleges and Universities Innovation Team Project of Chongqing of China(No.KJTD201020)the Scienceand Technology Project of Engineering Research Centre for Waste Oil,Ministry of Education of China(No.FYKJ2009012)
文摘N-F-codoped TiO2 （NFTO） photocatalysts were synthesized by a simple sol-gel process with tetrabutyl titanate （Ti（OBu）4 ） as the precursor of TiO 2 and ammonium fluoride （NH4 F） as the source of N and F.The synthesized photocatalysts were investigated by X- ray diffraction （XRD）,X-ray photoelectron spectroscopy （XPS）,ultraviolet-visible diffuse reflectance spectroscopy （UV-Vis DRS） and photodegradation reaction tests of 4-chlorophenol under visible light irradiation to understand the relationship between the structure of NFTO catalyst and corresponding photocatalytic activity.The crystal phase and particle size of catalysts were found to be largely affected by the calcination temperature.In addition,N-F-codoping could inhibit phase transition of TiO2 from anatase to rutile.The presence of N and F atoms in the lattice of TiO2 is responsible for the visible light catalytic activity.In UV-Vis DRS tests,the spectrum of NFTO exhibited red shift compared with Degussa P25 and the band gap was reduced to around 2.92 eV.Under optimal calcination temperature and dopant concentration conditions,the NFTO photocatalyst exhibited the highest activity in the photodegradation reaction tests of 4-chlorophenol under visible light irradiation with a degradation rate of 75.84%.Besides,the 5-recycle test showed that NFTO photocatalyst could be reused and its activity kept stable under visible light irradiation.
基金the Sao Paulo Research Foundation(FAPESP)(for the financial support,Grant numbers 2014/24940-5,and 2017/01462-9)the Brazilian National Council for Scientific Development(CNPq)for the fellowship given to Nathalia P.Ferraz,and to the Brazilian Metals and Mining Company(CBMM).
文摘The photocatalytic properties of CeO2-Nb2O5 photocatalysts in heterogeneous photocatalysis(under ultraviolet and visible radiation)and in Fenton-like process were reported.Methylene blue dye(MB)and phenol(Ph)were used as models of pollutant molecules for these reactions,and the photocatalysts were characterized by X-ray diffraction(XRD),diffuse reflectance spectroscopy(DRS),scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy(EDX)and thermally stimulated luminescence(TL).The results indicated that the addition of CeO2(0.3 wt%,1.0 wt%and 2.0 wt%)to Nb2O5 sensitized the resultant materials,increasing light absorption in the visible region.However,there is a suitable formulation of CeO2-Nb2O5 photocatalysts to improve each photocatalytic process.In heterogeneous photocatalysis,the addition of small CeO2 quantities to Nb2O5 was enough to improve the photocatalytic activity of CeO2-Nb2O5 photocatalysts(The best composition reported was CeO20.3 wt%.).The effectiveness of the catalyst was explained by the decrease in the number of trapping and luminescence centers in the conduction band of the material after the addition of CeO2 to Nb2O5,but a large amount of CeO2 decreased the number of trapping,luminescent and active centers to a large extent.Contrarily,in a Fenton-like process,the addition of CeO2 to Nb2O5 was favorable in all the proportions studied.(The best composition was 2.0 wt%CeO2.)In this case,the effectiveness was explained by the influence of the adsorption process(adsorption-triggered process),and the interactions between H2 O2 and Ce3+of the CeO2 in each photocatalyst thus formed surface peroxide species O22-,which induced the removal of the organic molecules under visible light.
文摘Polyaniline （PAn） sensitized nanocrystalline TiO2 composites （TiO2/PAn） were successfully prepared and used as an efficient photocatalyst for the degradation of dye methylene blue （MB）. The results showed that PAn was able to sensitize TiO2 efficiently and the composite photocatalyst could be activated by absorbing both the ultraviolet and visible light （λ： 190 ～ 800 nm）, whereas pure TiO2 absorbed ultraviolet light only （λ 〈 380 nm）. Under the irradiation of natural light, MB could be degraded more efficiently on the TiO2/PAn composites than on the TiO2 Furthermore, it could be easily separated from the solution by simple sedimentation.
