Extensive work on a Cu-modified TiO_(2) photocatalyst for CO_(2) reduction under visible light irradiation was conducted. The structure of the copper cocatalyst was established using UV-vis diff use refl ectance spect...Extensive work on a Cu-modified TiO_(2) photocatalyst for CO_(2) reduction under visible light irradiation was conducted. The structure of the copper cocatalyst was established using UV-vis diff use refl ectance spectroscopy, high-resolution transmis- sion electron microscopy, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy. It was found that copper exists in different states (Cu 0 , Cu^(+) , and Cu^(2+) ), the content of which depends on the TiO_(2) calcination temperature and copper loading. The optimum composition of the cocatalyst has a photocatalyst based on TiO_(2) calcined at 700℃ and modified with 5 wt% copper, the activity of which is 22 μmol/(h·g cat ) (409 nm). Analysis of the photocatalysts after the photocatalytic reaction disclosed that the copper metal on the surface of the calcined TiO_(2) was gradually converted into Cu_(2) O during the photocatalytic reaction. Meanwhile, the metallic copper on the surface of the noncalcined TiO_(2) did not undergo any trans- formation during the reaction.展开更多
The reduction of molecular nitrogen(N_(2))to ammonia(NH_(3))under mild conditions is one of the most promising studies in the energy field due to the important role of NH_(3)in modern industry,production,and life.The ...The reduction of molecular nitrogen(N_(2))to ammonia(NH_(3))under mild conditions is one of the most promising studies in the energy field due to the important role of NH_(3)in modern industry,production,and life.The photocatalytic reduction of N_(2)is expected to achieve clean and sustainable NH_(3)production by using clean solar energy.To date,the new photocatalysts for photocatalytic reduction of N_(2)to NH_(3)at room temperature and atmospheric pressure have not been fully developed.The major challenge is to achieve high light-absorption efficiency,conversion efficiency,and stability of photocatalysts.Herein,the methods for measuring produced NH_(3)are compared,and the problems related to possible NH_(3)pollution in photocatalytic systems are mentioned to provide accurate ideas for measuring photocatalytic efficiency.The recent progress of nitrogen reduction reaction(NRR)photocatalysts at ambient temperature and pressure is summarized by introducing charge transfer,migration,and separation in photocatalytic NRR,which provides a guidance for the selection of future photocatalyst.More importantly,we introduce the latest research strategies of photocatalysts in detail,which can guide the preparation and design of photocatalysts with high NRR activity.展开更多
Photocatalysis is an effective way to solve the problems of environmental pollution and energy shortage.Numerous photocatalysts have been developed and various strategies have been proposed to improve the photocatalyt...Photocatalysis is an effective way to solve the problems of environmental pollution and energy shortage.Numerous photocatalysts have been developed and various strategies have been proposed to improve the photocatalytic performance.Among them,Bi-based photocatalysts have become one of the most popular research topics due to their suitable band gaps,unique layered structures,and physicochemical properties.In this review,Bi-based photocatalysts(BiOX,BiVO_(4),Bi_(2)S_(3),Bi_(2)MoO_(6),and other Bi-based photocatalysts)have been summarized in the field of photocatalysis,including their applications of the removal of organic pollutants,hydrogen production,oxygen production etc.The preparation strategies on how to improve the photocatalytic performance and the possible photocatalytic mechanism are also summarized,which could supply new insights for fabricating high-efficient Bi-based photocatalysts.Finally,we summarize the current challenges and make a reasonable outlook on the future development direction of Bi-based photocatalysts.展开更多
AgCl/Ti_(3)C_(2)@TiO_(2)ternary composites were prepared to form a heterojunction structure between AgCl and TiO_(2)and introduce Ti3C2 as a cocatalyst.The as-prepared AgCl/Ti_(3)C_(2)@TiO_(2)composites showed higher ...AgCl/Ti_(3)C_(2)@TiO_(2)ternary composites were prepared to form a heterojunction structure between AgCl and TiO_(2)and introduce Ti3C2 as a cocatalyst.The as-prepared AgCl/Ti_(3)C_(2)@TiO_(2)composites showed higher photocatalytic activity than pure AgCl and Ti_(3)C_(2)@TiO_(2)for photooxidation of a 1,4-dihydropyridine derivative(1,4-DHP)and tetracycline hydrochloride(TCH)under visible light irradiation(λ>400 nm).The photocatalytic activity of AgCl/Ti_(3)C_(2)@TiO_(2)composites depended on Ti_(3)C_(2)@TiO_(2)content,and the catalytic activity of the optimized samples were 6.9 times higher than that of pure AgCl for 1,4-DHP photodehydrogenation and 7.3 times higher than that of Ti_(3)C_(2)@TiO_(2)for TCH photooxidation.The increased photocatalytic activity was due to the formation of a heterojunction structure between AgCl and TiO_(2)and the introduction of Ti3C2 as a cocatalyst,which lowered the internal resistance,sped up the charge transfer,and increased the separation efficiency of photogenerated carries.Photogenerated holes and superoxide radical anions were the major active species in the photocatalytic process.展开更多
Trace environmental pollutants have become a serious problem with special attention on the hazardous heavy metals, refractory organics, and pathogenic microorganisms. With coupling biosorption and photocatalysis to de...Trace environmental pollutants have become a serious problem with special attention on the hazardous heavy metals, refractory organics, and pathogenic microorganisms. With coupling biosorption and photocatalysis to develop biomaterial/TiO2 composite photocatalysts is a promising method to remove these trace pollutants because of the synergistic effect. Biomaterials provide multiple function groups which can selectively and efficiently enrich trace pollutants onto the surface of the photocatalysts, thus facilitating the following transformation mediated by TiO2 photocatalysis. Biomaterials can also help the dispersion and recovery of TiO2, or even modify the band structure of TiO2. The fabrication of chitosan/TiO2, cellulose/TiO2, as well as other biomaterial/TiO2 composite photocatalysts is discussed in detail in this review. The application significance of these composite photocatalysts for the selective removal of trace pollutants is also addressed. Several problems should be solved before the realistic applications can be achieved as discussed in the final section.展开更多
In recent years,the excessive use of antibiotics has become a serious problem for human health.BiV04 regarded as one of the most promising visible-light-driven photocatalysts was used to degrade the antibiotics.In thi...In recent years,the excessive use of antibiotics has become a serious problem for human health.BiV04 regarded as one of the most promising visible-light-driven photocatalysts was used to degrade the antibiotics.In this paper,we fabricated Bi/BiV04 plasmonic photocatalysts which enhanced the photocatalytic activity of BiV04 for degradation of tetracycline(TC)antibiotic.The Bi/BiV04 photocatalysts were characterized by X-ray diffraction,X-ray photoelectron spectroscopy,scanning electron microscopy,transmission electron microscopy and high-resolution transmission electron microscopy.In addition,the photocatalytic experiment results show that the 0.04-Bi/BiVO4 sample has the best photocatalytic activity for 2 times than the pure BiV04 photocatalyst.The cycle experiments,after four repetitions of the experiments,showed the sample still maintained a high photocatalytic activity.Finally,the photocatalytic reaction mechanism was also studied by free radical capture experiments and electron paramagnetic resonance spectroscopy.展开更多
Synthesis and characterization of hybrid fluorescent superparamagnetic core-shell particles of Fe@C-CNx composition are presented for the first time. The prepared Fe@C-CNx hybrid nanoparticles were found to possess mu...Synthesis and characterization of hybrid fluorescent superparamagnetic core-shell particles of Fe@C-CNx composition are presented for the first time. The prepared Fe@C-CNx hybrid nanoparticles were found to possess multifunctionality by exhibiting strong superparamagnetic properties and bright fluorescence emissions at 500 nm after the excitation with light in the UV-visible range. Fe@C-CNx also exhibits photocatalytic activities for organic dye degradation comparable to pure amorphous CNx with reusability through magnetic separation. The combination of magnetic and fluorescent properties of core-shell Fe@C-CNx nanoparticles opens opportunities for their application as sensors and magnet manipulated reusable photocatalysts. Superparamagnetic Fe@C core-shell nanoparticles were used as the template material in the synthesis, where the carbon shell was functionalized through one-step free-radical addition of alkyl groups terminated with carboxylic acid moieties. The method utilizes the organic acyl peroxide of dicarboxylic acid (succinic acid peroxide) as a non-oxidant functional free radical precursor for functionalization. Further, covalently functionalized succinyl-Fe@C core-shell nanoparticles were coated with the amorphous carbon nitride (CNx) generated by an in-situ solution-based chemical reaction of cyanuric chloride with lithium nitride. A detailed physicochemical characterization of the microstructure, magnetic and fluorescence properties of the synthesized hybrid nanoparticles is provided.展开更多
A series of nanocrystalline V-doped (0.0-3.0 at.%) TiO2 catalysts have been successfully prepared by the one-step solution combustion method using urea as a fuel. The obtained powders were characterized by XRD, SEM,...A series of nanocrystalline V-doped (0.0-3.0 at.%) TiO2 catalysts have been successfully prepared by the one-step solution combustion method using urea as a fuel. The obtained powders were characterized by XRD, SEM, Raman, XPS and UV-Vis DRS. The effects of V doping concentration on the phase structure and photocatalytic properties were investigated. XRD, Raman, and XPS show that V doping diffuses into TiO2 crystal lattice mainly in the form of V5+ and causes a phase transition from anatase to mille. V doping can widen the light absorption range of TiO2, with the absorption threshold wavelength shifting from 425 to 625 nm. The photocatalytic activity of V-doped TiO2 powders were evaluated by the photocatalytic degradation of methyl orange (MO) under visible light irradiation. It is found that V doping enhances the photoeatalyilc activity under visible light irradiation and the optimal degradation rate of MO is about 95.8% with 1.0 at% V-doped TiO2.展开更多
Building a covalently connected structure with accelerated photo-induced electrons and charge-carrier separation between semiconductors could enhance the photocatalytic performance.In this work,we report a facile and ...Building a covalently connected structure with accelerated photo-induced electrons and charge-carrier separation between semiconductors could enhance the photocatalytic performance.In this work,we report a facile and novel seed growth method to coat NH2-MIL-125 MOFs with crystalline and porous covalent organic frameworks(COFs)materials and form a range of NH2-MIL-125@TAPB-PDA nanocomposites with different thicknesses of COF shell.The introduction of appropriate content of COF could not only modify the intrinsic electronic and optical properties,but also enhance the photocatalytic activity distinctly.Especially,NH2-MIL-125@TAPB-PDA-3 with COF shell thickness of around 20nm exhibited the highest yield(94.7%)of benzaldehyde which is approximately 2.5 and 15.5 times as that of parental NH2-MIL-125 and COF,respectively.The promoted photocatalytic performance of hybrid materials was mainly owing to the enhanced photo-induced charge carriers transfer between the MOF and COF through the covalent bond.In addition,a possible mechanism to elucidate the process of photocatalysis was explored.Therefore,this kind of MOF-based photocatalysts possesses great potentials in future green organic synthesis.展开更多
In this contribution, an efficient and simple two-step hybrid electrochemical-thermal route was developed for the synthesis of cubic shaped Zn_2SnO_4 (ZTO) nanoparticles using aqueous sodium bicarbonate(NaHCO_3) and s...In this contribution, an efficient and simple two-step hybrid electrochemical-thermal route was developed for the synthesis of cubic shaped Zn_2SnO_4 (ZTO) nanoparticles using aqueous sodium bicarbonate(NaHCO_3) and sodium stannate(Na_2SnO_3) electrolyte. The sacrificial Zn was used as anode and cathode in an undivided cell under galvanostatic mode at room temperature. The bath concentration and current density were respectively varied from 30 to 120 mmol and 0.05 to 1.5 A/dm^2. The electrochemically generated precursor was calcined for an hour at different range of temperature from 60 to 600. The crystallite sizes in the range of 24-53 nm were calculated based on Debye-Scherrer equation. Scanning electron microscope and transmission electron microscopy results reveal that all the particles have cubic morphology with diameter of40-50 nm. The as-prepared ZTO samples showed higher catalytic activity towards the degradation of methylene blue(MB) dye, and 90% degradation was found for the sample calcined at 600, which is greater than that of commercial TiO_2-P25 photocatalysts. The photodegradation efficiency of ZTO samples was found to be a function of exposure time and the dye solution p H value. These results indicate that the ZTO nanoparticles may be employed to remove dyes from wastewater.展开更多
Electrostatic self-assembly method (ESAM) was used to prepare bentonite supported-nano titanium dioxide photocatalysts. The materials were characterized by X-ray diffraction (XRD), fourier transform infrared spect...Electrostatic self-assembly method (ESAM) was used to prepare bentonite supported-nano titanium dioxide photocatalysts. The materials were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Methyl orange was used to estimate the photocatalytic activity of the materials. The effects of the calcination temperature and silane dosage on the photocatalytic activity of the samples were investigated. The experimental results show that the bentonite facilitates the formation of anatase and restrains the transformation of anatase to rutile. Part of nano-size TiO2 particles insert into the galleries of bentonite. The photocatalysts exhibit a synergistic effect of adsorption and photocatalysis on methyl orange. Photocatalysts prepared by ESAM method exhibit higher photocatalytic activity and better recycle ability than those of the traditional method.展开更多
COconversion via photocatalysis is a potential solution to address global warming and energy shortage.Photocatalysis can directly utilize the inexhaustible sunlight as an energy source to catalyze the reduction of COt...COconversion via photocatalysis is a potential solution to address global warming and energy shortage.Photocatalysis can directly utilize the inexhaustible sunlight as an energy source to catalyze the reduction of COto useful solar fuels such as CO, CH, CHOH, and CHOH. Among studied formulations, Cubased photocatalysts are the most attractive for COconversion because the Cu-based photocatalysts are low-cost and abundance comparing noble metal-based catalysts. In this literature review, a comprehensive summary of recent progress on Cu-based photocatalysts for COconversion, which includes metallic copper, copper alloy nanoparticles(NPs), copper oxides, and copper sulfides photocatalysts, can be found. This review also included a detailed discussion on the correlations of morphology, structure, and performance for each type of Cu-based catalysts. The reaction mechanisms and possible pathways for productions of various solar fuels were analyzed, which provide insight into the nature of potential active sites for the catalysts. Finally, the current challenges and perspective future research directions were outlined, holding promise to advance Cu-based photocatalysts for COconversion with much-enhanced energy conversion efficiency and production rates.展开更多
The particles of titanium-iron (Ti/Fe) complex with different Fe contents were prepared by means of the sol-gel method and used as a photocatalyst. The activity of the catalyst was investi- gated as a function of the ...The particles of titanium-iron (Ti/Fe) complex with different Fe contents were prepared by means of the sol-gel method and used as a photocatalyst. The activity of the catalyst was investi- gated as a function of the Fe content during the liquid-phase oxidation of tetracycline, which showed an enhancement at the low Fe content. The XRD, Raman, XPS, and UV-Vis absorp- tion spectra indicated that the crystalline structure of the Ti/Fe complex particles changed from anatase phase to rutile phase when the Fe content increased. The isolated Fe203, Fe304, FeO species were observed and Fe3+ ions were highly dispersed in the TiO2 matrixes, then Ti-O-Fe species were formed. These species increased the surface defects of the Ti/Fe particles. Also, ac- tive hydroxyl radicals could be generated in the catalytic transformation, which led to the higher activity of the catalyst than bare Ti02 for the degradation of tetracycline.展开更多
Magnetic TiO2/SiO2/NiFe204 composite photocatalytic particles with high crystalline TiO2 shell were synthesized via a mild solution route. The prepared composite particles were characterized with X-ray diffraction(XR...Magnetic TiO2/SiO2/NiFe204 composite photocatalytic particles with high crystalline TiO2 shell were synthesized via a mild solution route. The prepared composite particles were characterized with X-ray diffraction(XRD), transmission electron microscopy(TEM), high resolution transmission electron microscopy(HRTEM), scanning electron microscopy(SEM), ultraviolet-visible(UV-Vis) spectroscopy and vibrating sample magnetometer(VSM). The results show that the obtained TiO2/SiO2/NiFe2O4 composite particles were composed of spherical nanoparticles, about 30 nm in diameter, with several NiFe/O4 fine particles about 20 nm in diameter as cores and silica as coatings and barrier layers between the magnetic cores and titania shells. The photocatalytic activity of the composite photocatalytic particles was also investigated for the degradation of Basic Violet 5BN(BV5) under UV irradiation. About 97% of original BV5 decomposed in 360 min in the presence of magnetic composite nanoparticles under UV light. The synthesized magnetic composite nanoparticles exhibited high photocatalytic efficiency that would find potential application to cleaning polluted water with the help of magnetic separation.展开更多
The magnetically separable ternary polyetherimide/titanate@Fe3O4(PTF) photocatalysts of special heterostructure between magnetite(Fe3O4) microspheres and titanates nanosheets modified by polyetherimide(PEI) were succe...The magnetically separable ternary polyetherimide/titanate@Fe3O4(PTF) photocatalysts of special heterostructure between magnetite(Fe3O4) microspheres and titanates nanosheets modified by polyetherimide(PEI) were successfully fabricated via a simple facile hydrothermal deposition method. The as-prepared photocatalysts were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Transmission electron microscopy and UV-vis diffuse reflectance spectroscopy etc. The results showed that the as-fabricated material had a structure of Fe3O4microspheres coated with titanates nanosheets modified by PEI. The special interfacial contact between 3 D microsphere and 2 D nanosheets in the nanoarchitectures was formed via electrostatic attraction. Furthermore, the resulted photocatalysts were tested by degradation reaction of methylene blue under visible light irradiation and demonstrated an enhanced performance than the pure Fe3O4microspheres, and the photocatalytic activity enhanced with the molar ratio of Fe3O4microspheres and modified titanate gradually, which was attributed to the expansion of the surface area and the different electrostatic contact between the Fe3O4microspheres and titanate nanosheets. Moreover, the obtained results revealed the high yield magnetic separation and efficient reusability of PTF-5(96.7%) over 3 times reuse.展开更多
Photocatalysts with perovskites for hydrogen production from aqueous solution were reviewed. Among the most of metal oxide photocatalysts, the family of ABO3 Perovskite-type oxide shows higher photocatalytic activity,...Photocatalysts with perovskites for hydrogen production from aqueous solution were reviewed. Among the most of metal oxide photocatalysts, the family of ABO3 Perovskite-type oxide shows higher photocatalytic activity, especially alkaline earth titanate and alkali tantalate. Therein, sodium tantalate showed the highest activity for water splitting. The reasons for the high photocatalytic activity of ABO3 perovskties are considered to the diverse and flexible crystal structure. The photocatalytic activity of ABO3 perovskties can be improved by doping other element at A site, B site or O site and loading co-catalysts such as NiO and Pt. In this paper, the mechanism of photocatalytic water splitting, the structure of ABO3 perovsktie, and Perovskite-type photocatalysts were reviewed.展开更多
The interest in CO_(2)conversion to value-added chemicals and fuels has increased in recent years as part of strategic eff orts to mitigate and use the excessive CO_(2)concentration in the atmosphere.Much attention ha...The interest in CO_(2)conversion to value-added chemicals and fuels has increased in recent years as part of strategic eff orts to mitigate and use the excessive CO_(2)concentration in the atmosphere.Much attention has been given to developing two-dimensional catalytic materials with high-effi ciency CO_(2)adsorption capability and conversion yield.While several candidates are being investigated,MXenes stand out as one of the most promising catalysts and co-catalysts for CO_(2)reduction,given their excellent surface functionalities,unique layered structures,high surface areas,rich active sites,and high chemical sta-bility.This review aims to highlight research progress and recent developments in the application of MXene-based catalysts for CO_(2)conversion to value-added chemicals,paying special attention to photoreduction and electroreduction.Furthermore,the underlying photocatalytic and electrocatalytic CO_(2)conversion mechanisms are discussed.Finally,we provide an outlook for future research in this fi eld,including photoelectrocatalysis and photothermal CO_(2)reduction.展开更多
Nest-like and multilayered-disk-like Bi2WO6 photocatalysts were synthesized through a hydrothermal strategy using thiourea and acetic acid as complexing agents. The nest-like Bi2WO6 showed excellent visible-light-driv...Nest-like and multilayered-disk-like Bi2WO6 photocatalysts were synthesized through a hydrothermal strategy using thiourea and acetic acid as complexing agents. The nest-like Bi2WO6 showed excellent visible-light-driven photocatalytic performance, and it could decompose rhodamine B(RhB) within 100 minutes. This excellent performance resulted from its special microstructure and the relatively large surface area.展开更多
A series of CdxZn1-xS (x = 0.1-0.9) photocatalysts were prepared by coprecipitation. They could form solid solution semiconductors with hexagonal phase in agreement with pure CdS by characterization of XRD. The photop...A series of CdxZn1-xS (x = 0.1-0.9) photocatalysts were prepared by coprecipitation. They could form solid solution semiconductors with hexagonal phase in agreement with pure CdS by characterization of XRD. The photophysical properties of CdxZn1-xS photocatalysts were measured by UV-Vis diffuse reflectance spectrum and surface photovoltage spectroscopy (SPS). The band gap energy gradually reduced with the increasing of x value in CdxZn1-xS,and when x = 0.7,the Cd0.7Zn0.3S photocatalyst had the strongest sur...展开更多
Due to its fascinating and tunable optoelectronic properties,semiconductor nanomaterials are the best choices for multidisciplinary applications.Particularly,the use of semiconductor photocatalysts is one of the promi...Due to its fascinating and tunable optoelectronic properties,semiconductor nanomaterials are the best choices for multidisciplinary applications.Particularly,the use of semiconductor photocatalysts is one of the promising ways to harness solar energy for useful applications in the field of energy and environment.In recent years,metal oxide-based tailored semiconductor photocatalysts have extensively been used for photocatalytic conversion of carbon dioxide(CO_(2))into fuels and other useful products utilizing solar energy.This is very significant not only from renewable energy consumption but also from reducing global warming point of view.Such current research activities are promising for a better future of society.The present mini-review is focused on recent developments(2–3 years)in metal oxide semiconductor hybrid photocatalysts-based photo-electrochemical conversion of CO_(2)into fuels and other useful products.First,general mechanism of photo-electrochemical conversion of CO_(2)into fuels or other useful products has been discussed.Then,various metal oxide-based emerging hybrid photocatalysts including tailoring of their morphological,compositional,and optoelectronic properties have been discussed with emphasis on their role in enhancing photoelectrochemical efficienty.Afterwards,mechanism of their photo-electrochemical reactions and applications in CO_(2)conversion into fuels/other useful products have been discussed.Finally,challenges and future prospects have been discussed followed by a summary.展开更多
基金supported by Russian Science Foundation (No.#21-73-10235)
文摘Extensive work on a Cu-modified TiO_(2) photocatalyst for CO_(2) reduction under visible light irradiation was conducted. The structure of the copper cocatalyst was established using UV-vis diff use refl ectance spectroscopy, high-resolution transmis- sion electron microscopy, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy. It was found that copper exists in different states (Cu 0 , Cu^(+) , and Cu^(2+) ), the content of which depends on the TiO_(2) calcination temperature and copper loading. The optimum composition of the cocatalyst has a photocatalyst based on TiO_(2) calcined at 700℃ and modified with 5 wt% copper, the activity of which is 22 μmol/(h·g cat ) (409 nm). Analysis of the photocatalysts after the photocatalytic reaction disclosed that the copper metal on the surface of the calcined TiO_(2) was gradually converted into Cu_(2) O during the photocatalytic reaction. Meanwhile, the metallic copper on the surface of the noncalcined TiO_(2) did not undergo any trans- formation during the reaction.
基金Taishan Scholars Program of Shandong Province,Grant/Award Number:tsqn201812068Higher School Youth Innovation Team of Shandong Province,Grant/Award Number:2019KJA013+1 种基金The Opening Fund of State Key Laboratory of Heavy Oil Processing,Grant/Award Number:SKLOP202002006National Natural Science Foundation of China,Grant/Award Number:51872173。
文摘The reduction of molecular nitrogen(N_(2))to ammonia(NH_(3))under mild conditions is one of the most promising studies in the energy field due to the important role of NH_(3)in modern industry,production,and life.The photocatalytic reduction of N_(2)is expected to achieve clean and sustainable NH_(3)production by using clean solar energy.To date,the new photocatalysts for photocatalytic reduction of N_(2)to NH_(3)at room temperature and atmospheric pressure have not been fully developed.The major challenge is to achieve high light-absorption efficiency,conversion efficiency,and stability of photocatalysts.Herein,the methods for measuring produced NH_(3)are compared,and the problems related to possible NH_(3)pollution in photocatalytic systems are mentioned to provide accurate ideas for measuring photocatalytic efficiency.The recent progress of nitrogen reduction reaction(NRR)photocatalysts at ambient temperature and pressure is summarized by introducing charge transfer,migration,and separation in photocatalytic NRR,which provides a guidance for the selection of future photocatalyst.More importantly,we introduce the latest research strategies of photocatalysts in detail,which can guide the preparation and design of photocatalysts with high NRR activity.
基金We gratefully acknowledge the support of this research by the National Natural Science Foundation of China(52172206,21871078)the Heilongjiang Province Natural Science Foundation of China(JQ2019B001)+4 种基金the Shandong Province Natural Science Foundation(ZR2021MB016)the Heilongjiang Provincial Institutions of Higher Learning Basic Research Funds Basic Research Projects(2021-KYYWF-0007)the Heilongjiang Postdoctoral Startup Fund(LBH-Q14135)the Heilongjiang University Science Fund for Distinguished Young Scholars(JCL201802)the Development plan of Youth Innovation Team in Colleges and Universities of Shandong Province.
文摘Photocatalysis is an effective way to solve the problems of environmental pollution and energy shortage.Numerous photocatalysts have been developed and various strategies have been proposed to improve the photocatalytic performance.Among them,Bi-based photocatalysts have become one of the most popular research topics due to their suitable band gaps,unique layered structures,and physicochemical properties.In this review,Bi-based photocatalysts(BiOX,BiVO_(4),Bi_(2)S_(3),Bi_(2)MoO_(6),and other Bi-based photocatalysts)have been summarized in the field of photocatalysis,including their applications of the removal of organic pollutants,hydrogen production,oxygen production etc.The preparation strategies on how to improve the photocatalytic performance and the possible photocatalytic mechanism are also summarized,which could supply new insights for fabricating high-efficient Bi-based photocatalysts.Finally,we summarize the current challenges and make a reasonable outlook on the future development direction of Bi-based photocatalysts.
基金This work was supported by the Opening Project of the Key Laboratory of Green Chemistry of Sichuan Institutes of Higher Education(LZJ2002)the Open Project of Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province(CSPC2016-3-2).
文摘AgCl/Ti_(3)C_(2)@TiO_(2)ternary composites were prepared to form a heterojunction structure between AgCl and TiO_(2)and introduce Ti3C2 as a cocatalyst.The as-prepared AgCl/Ti_(3)C_(2)@TiO_(2)composites showed higher photocatalytic activity than pure AgCl and Ti_(3)C_(2)@TiO_(2)for photooxidation of a 1,4-dihydropyridine derivative(1,4-DHP)and tetracycline hydrochloride(TCH)under visible light irradiation(λ>400 nm).The photocatalytic activity of AgCl/Ti_(3)C_(2)@TiO_(2)composites depended on Ti_(3)C_(2)@TiO_(2)content,and the catalytic activity of the optimized samples were 6.9 times higher than that of pure AgCl for 1,4-DHP photodehydrogenation and 7.3 times higher than that of Ti_(3)C_(2)@TiO_(2)for TCH photooxidation.The increased photocatalytic activity was due to the formation of a heterojunction structure between AgCl and TiO_(2)and the introduction of Ti3C2 as a cocatalyst,which lowered the internal resistance,sped up the charge transfer,and increased the separation efficiency of photogenerated carries.Photogenerated holes and superoxide radical anions were the major active species in the photocatalytic process.
基金Supported by the National Natural Science Foundation of China(21525625,21838001)the National Basic Research Program(973 Program)of China(2014CB745100)+1 种基金the(863)High Technology Project of China(2013AA020302)the Chinese Universities Scientific Fund(JD1417)
文摘Trace environmental pollutants have become a serious problem with special attention on the hazardous heavy metals, refractory organics, and pathogenic microorganisms. With coupling biosorption and photocatalysis to develop biomaterial/TiO2 composite photocatalysts is a promising method to remove these trace pollutants because of the synergistic effect. Biomaterials provide multiple function groups which can selectively and efficiently enrich trace pollutants onto the surface of the photocatalysts, thus facilitating the following transformation mediated by TiO2 photocatalysis. Biomaterials can also help the dispersion and recovery of TiO2, or even modify the band structure of TiO2. The fabrication of chitosan/TiO2, cellulose/TiO2, as well as other biomaterial/TiO2 composite photocatalysts is discussed in detail in this review. The application significance of these composite photocatalysts for the selective removal of trace pollutants is also addressed. Several problems should be solved before the realistic applications can be achieved as discussed in the final section.
基金Supported by the National Natural Science Foundation of China(21522603,21503142,21671083)Six Talent Peaks Project in Jiangsu Province(XCL-025)+1 种基金the China Postdoctoral Science Foundation(2017M611720)the Excellent Youth Foundation of Jiangsu Scientific Committee(BK20170526).
文摘In recent years,the excessive use of antibiotics has become a serious problem for human health.BiV04 regarded as one of the most promising visible-light-driven photocatalysts was used to degrade the antibiotics.In this paper,we fabricated Bi/BiV04 plasmonic photocatalysts which enhanced the photocatalytic activity of BiV04 for degradation of tetracycline(TC)antibiotic.The Bi/BiV04 photocatalysts were characterized by X-ray diffraction,X-ray photoelectron spectroscopy,scanning electron microscopy,transmission electron microscopy and high-resolution transmission electron microscopy.In addition,the photocatalytic experiment results show that the 0.04-Bi/BiVO4 sample has the best photocatalytic activity for 2 times than the pure BiV04 photocatalyst.The cycle experiments,after four repetitions of the experiments,showed the sample still maintained a high photocatalytic activity.Finally,the photocatalytic reaction mechanism was also studied by free radical capture experiments and electron paramagnetic resonance spectroscopy.
文摘Synthesis and characterization of hybrid fluorescent superparamagnetic core-shell particles of Fe@C-CNx composition are presented for the first time. The prepared Fe@C-CNx hybrid nanoparticles were found to possess multifunctionality by exhibiting strong superparamagnetic properties and bright fluorescence emissions at 500 nm after the excitation with light in the UV-visible range. Fe@C-CNx also exhibits photocatalytic activities for organic dye degradation comparable to pure amorphous CNx with reusability through magnetic separation. The combination of magnetic and fluorescent properties of core-shell Fe@C-CNx nanoparticles opens opportunities for their application as sensors and magnet manipulated reusable photocatalysts. Superparamagnetic Fe@C core-shell nanoparticles were used as the template material in the synthesis, where the carbon shell was functionalized through one-step free-radical addition of alkyl groups terminated with carboxylic acid moieties. The method utilizes the organic acyl peroxide of dicarboxylic acid (succinic acid peroxide) as a non-oxidant functional free radical precursor for functionalization. Further, covalently functionalized succinyl-Fe@C core-shell nanoparticles were coated with the amorphous carbon nitride (CNx) generated by an in-situ solution-based chemical reaction of cyanuric chloride with lithium nitride. A detailed physicochemical characterization of the microstructure, magnetic and fluorescence properties of the synthesized hybrid nanoparticles is provided.
基金Funded by the National Natural Science Foundation of China(Nos.51002054,51272079)the Fundamental Research Fundsfor the Central Universities,HUST(No.2011TS014)
文摘A series of nanocrystalline V-doped (0.0-3.0 at.%) TiO2 catalysts have been successfully prepared by the one-step solution combustion method using urea as a fuel. The obtained powders were characterized by XRD, SEM, Raman, XPS and UV-Vis DRS. The effects of V doping concentration on the phase structure and photocatalytic properties were investigated. XRD, Raman, and XPS show that V doping diffuses into TiO2 crystal lattice mainly in the form of V5+ and causes a phase transition from anatase to mille. V doping can widen the light absorption range of TiO2, with the absorption threshold wavelength shifting from 425 to 625 nm. The photocatalytic activity of V-doped TiO2 powders were evaluated by the photocatalytic degradation of methyl orange (MO) under visible light irradiation. It is found that V doping enhances the photoeatalyilc activity under visible light irradiation and the optimal degradation rate of MO is about 95.8% with 1.0 at% V-doped TiO2.
基金the National Key Research and Development Program of China(No.2016YFB0701100)the National Natural Science Foundation of China(Nos.51802015 and 51890893)Fundamental Research Funds for the Central Universities(FRFTP-16-028A1)。
文摘Building a covalently connected structure with accelerated photo-induced electrons and charge-carrier separation between semiconductors could enhance the photocatalytic performance.In this work,we report a facile and novel seed growth method to coat NH2-MIL-125 MOFs with crystalline and porous covalent organic frameworks(COFs)materials and form a range of NH2-MIL-125@TAPB-PDA nanocomposites with different thicknesses of COF shell.The introduction of appropriate content of COF could not only modify the intrinsic electronic and optical properties,but also enhance the photocatalytic activity distinctly.Especially,NH2-MIL-125@TAPB-PDA-3 with COF shell thickness of around 20nm exhibited the highest yield(94.7%)of benzaldehyde which is approximately 2.5 and 15.5 times as that of parental NH2-MIL-125 and COF,respectively.The promoted photocatalytic performance of hybrid materials was mainly owing to the enhanced photo-induced charge carriers transfer between the MOF and COF through the covalent bond.In addition,a possible mechanism to elucidate the process of photocatalysis was explored.Therefore,this kind of MOF-based photocatalysts possesses great potentials in future green organic synthesis.
文摘In this contribution, an efficient and simple two-step hybrid electrochemical-thermal route was developed for the synthesis of cubic shaped Zn_2SnO_4 (ZTO) nanoparticles using aqueous sodium bicarbonate(NaHCO_3) and sodium stannate(Na_2SnO_3) electrolyte. The sacrificial Zn was used as anode and cathode in an undivided cell under galvanostatic mode at room temperature. The bath concentration and current density were respectively varied from 30 to 120 mmol and 0.05 to 1.5 A/dm^2. The electrochemically generated precursor was calcined for an hour at different range of temperature from 60 to 600. The crystallite sizes in the range of 24-53 nm were calculated based on Debye-Scherrer equation. Scanning electron microscope and transmission electron microscopy results reveal that all the particles have cubic morphology with diameter of40-50 nm. The as-prepared ZTO samples showed higher catalytic activity towards the degradation of methylene blue(MB) dye, and 90% degradation was found for the sample calcined at 600, which is greater than that of commercial TiO_2-P25 photocatalysts. The photodegradation efficiency of ZTO samples was found to be a function of exposure time and the dye solution p H value. These results indicate that the ZTO nanoparticles may be employed to remove dyes from wastewater.
基金Funded by the Natural Science Foundation of Hebei Province, China (No. E2008000537)the Foundation for Development of Science and Technology of Hebei Province, China (No. 07215156)the Open Research Foundation of Key Laboratory of Advanced Civil Engineering Materials (Tongji University),Ministry of Education, China (No. 2010412)
文摘Electrostatic self-assembly method (ESAM) was used to prepare bentonite supported-nano titanium dioxide photocatalysts. The materials were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Methyl orange was used to estimate the photocatalytic activity of the materials. The effects of the calcination temperature and silane dosage on the photocatalytic activity of the samples were investigated. The experimental results show that the bentonite facilitates the formation of anatase and restrains the transformation of anatase to rutile. Part of nano-size TiO2 particles insert into the galleries of bentonite. The photocatalysts exhibit a synergistic effect of adsorption and photocatalysis on methyl orange. Photocatalysts prepared by ESAM method exhibit higher photocatalytic activity and better recycle ability than those of the traditional method.
基金financial supports from the National 1000 Young Talents Program of Chinathe National Nature Science Foundation of China (21603078)+1 种基金the National Materials Genome Project (2016YFB0700600)financial support from Research and Education in eNergy, Environment and Water (RENEW)Institute at the University at Buffalo, SUNY
文摘COconversion via photocatalysis is a potential solution to address global warming and energy shortage.Photocatalysis can directly utilize the inexhaustible sunlight as an energy source to catalyze the reduction of COto useful solar fuels such as CO, CH, CHOH, and CHOH. Among studied formulations, Cubased photocatalysts are the most attractive for COconversion because the Cu-based photocatalysts are low-cost and abundance comparing noble metal-based catalysts. In this literature review, a comprehensive summary of recent progress on Cu-based photocatalysts for COconversion, which includes metallic copper, copper alloy nanoparticles(NPs), copper oxides, and copper sulfides photocatalysts, can be found. This review also included a detailed discussion on the correlations of morphology, structure, and performance for each type of Cu-based catalysts. The reaction mechanisms and possible pathways for productions of various solar fuels were analyzed, which provide insight into the nature of potential active sites for the catalysts. Finally, the current challenges and perspective future research directions were outlined, holding promise to advance Cu-based photocatalysts for COconversion with much-enhanced energy conversion efficiency and production rates.
基金Shanghai Education Committee Science Development Foundation.
文摘The particles of titanium-iron (Ti/Fe) complex with different Fe contents were prepared by means of the sol-gel method and used as a photocatalyst. The activity of the catalyst was investi- gated as a function of the Fe content during the liquid-phase oxidation of tetracycline, which showed an enhancement at the low Fe content. The XRD, Raman, XPS, and UV-Vis absorp- tion spectra indicated that the crystalline structure of the Ti/Fe complex particles changed from anatase phase to rutile phase when the Fe content increased. The isolated Fe203, Fe304, FeO species were observed and Fe3+ ions were highly dispersed in the TiO2 matrixes, then Ti-O-Fe species were formed. These species increased the surface defects of the Ti/Fe particles. Also, ac- tive hydroxyl radicals could be generated in the catalytic transformation, which led to the higher activity of the catalyst than bare Ti02 for the degradation of tetracycline.
基金Supported by the National Natural Science Foundation of China(No.20803089)the Fund of Science and Technology of Shanxi Province for Young Scholars,China(Nos.2007021012,2008021010)
文摘Magnetic TiO2/SiO2/NiFe204 composite photocatalytic particles with high crystalline TiO2 shell were synthesized via a mild solution route. The prepared composite particles were characterized with X-ray diffraction(XRD), transmission electron microscopy(TEM), high resolution transmission electron microscopy(HRTEM), scanning electron microscopy(SEM), ultraviolet-visible(UV-Vis) spectroscopy and vibrating sample magnetometer(VSM). The results show that the obtained TiO2/SiO2/NiFe2O4 composite particles were composed of spherical nanoparticles, about 30 nm in diameter, with several NiFe/O4 fine particles about 20 nm in diameter as cores and silica as coatings and barrier layers between the magnetic cores and titania shells. The photocatalytic activity of the composite photocatalytic particles was also investigated for the degradation of Basic Violet 5BN(BV5) under UV irradiation. About 97% of original BV5 decomposed in 360 min in the presence of magnetic composite nanoparticles under UV light. The synthesized magnetic composite nanoparticles exhibited high photocatalytic efficiency that would find potential application to cleaning polluted water with the help of magnetic separation.
基金Funded by the National Natural Science Foundation of China(Nos.21103054,21003055,and 50872037)the Open Fund of Fujian Provincial Key Laboratory of Functional Materials and Applications(Xiamen University of Technology)(No.608160030215)the Program for Innovative Research Team in Science and Technology in Fujian Province University(IRTSTFJ)
文摘The magnetically separable ternary polyetherimide/titanate@Fe3O4(PTF) photocatalysts of special heterostructure between magnetite(Fe3O4) microspheres and titanates nanosheets modified by polyetherimide(PEI) were successfully fabricated via a simple facile hydrothermal deposition method. The as-prepared photocatalysts were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Transmission electron microscopy and UV-vis diffuse reflectance spectroscopy etc. The results showed that the as-fabricated material had a structure of Fe3O4microspheres coated with titanates nanosheets modified by PEI. The special interfacial contact between 3 D microsphere and 2 D nanosheets in the nanoarchitectures was formed via electrostatic attraction. Furthermore, the resulted photocatalysts were tested by degradation reaction of methylene blue under visible light irradiation and demonstrated an enhanced performance than the pure Fe3O4microspheres, and the photocatalytic activity enhanced with the molar ratio of Fe3O4microspheres and modified titanate gradually, which was attributed to the expansion of the surface area and the different electrostatic contact between the Fe3O4microspheres and titanate nanosheets. Moreover, the obtained results revealed the high yield magnetic separation and efficient reusability of PTF-5(96.7%) over 3 times reuse.
文摘Photocatalysts with perovskites for hydrogen production from aqueous solution were reviewed. Among the most of metal oxide photocatalysts, the family of ABO3 Perovskite-type oxide shows higher photocatalytic activity, especially alkaline earth titanate and alkali tantalate. Therein, sodium tantalate showed the highest activity for water splitting. The reasons for the high photocatalytic activity of ABO3 perovskties are considered to the diverse and flexible crystal structure. The photocatalytic activity of ABO3 perovskties can be improved by doping other element at A site, B site or O site and loading co-catalysts such as NiO and Pt. In this paper, the mechanism of photocatalytic water splitting, the structure of ABO3 perovsktie, and Perovskite-type photocatalysts were reviewed.
基金the internal financial support of Universitas Airlangga through Riset Mandat Muda No.399/UN3.14/PT2020support of the National Research and Innovation Agency,Republic of Indonesia+1 种基金support of the Singapore National Research Foundation(NRF-NRFF2017-04)the Agency for Science,Technology and Research(Central Research Fund Award)。
文摘The interest in CO_(2)conversion to value-added chemicals and fuels has increased in recent years as part of strategic eff orts to mitigate and use the excessive CO_(2)concentration in the atmosphere.Much attention has been given to developing two-dimensional catalytic materials with high-effi ciency CO_(2)adsorption capability and conversion yield.While several candidates are being investigated,MXenes stand out as one of the most promising catalysts and co-catalysts for CO_(2)reduction,given their excellent surface functionalities,unique layered structures,high surface areas,rich active sites,and high chemical sta-bility.This review aims to highlight research progress and recent developments in the application of MXene-based catalysts for CO_(2)conversion to value-added chemicals,paying special attention to photoreduction and electroreduction.Furthermore,the underlying photocatalytic and electrocatalytic CO_(2)conversion mechanisms are discussed.Finally,we provide an outlook for future research in this fi eld,including photoelectrocatalysis and photothermal CO_(2)reduction.
基金Funded by the National Natural Science Foundation of China(A3 Foresight Project No.50821140308)
文摘Nest-like and multilayered-disk-like Bi2WO6 photocatalysts were synthesized through a hydrothermal strategy using thiourea and acetic acid as complexing agents. The nest-like Bi2WO6 showed excellent visible-light-driven photocatalytic performance, and it could decompose rhodamine B(RhB) within 100 minutes. This excellent performance resulted from its special microstructure and the relatively large surface area.
基金the National High-Tech Research and Development Program of China (No. 2007AA03Z337)the Heilongjiang Science Fund for Distinguished Young Scholars (No. JC200615)the Technical Cooperation Project of Harbin with Russia(No.2006AA4BE053).
文摘A series of CdxZn1-xS (x = 0.1-0.9) photocatalysts were prepared by coprecipitation. They could form solid solution semiconductors with hexagonal phase in agreement with pure CdS by characterization of XRD. The photophysical properties of CdxZn1-xS photocatalysts were measured by UV-Vis diffuse reflectance spectrum and surface photovoltage spectroscopy (SPS). The band gap energy gradually reduced with the increasing of x value in CdxZn1-xS,and when x = 0.7,the Cd0.7Zn0.3S photocatalyst had the strongest sur...
基金supported financially by Department of Science and Techanology,India,Institut National de la Recherche Scientifique(INRS),andÉcole de Technologie Supérieure(ÉTS),the Marcelle-Gauvreau Engineering Research Chair program。
文摘Due to its fascinating and tunable optoelectronic properties,semiconductor nanomaterials are the best choices for multidisciplinary applications.Particularly,the use of semiconductor photocatalysts is one of the promising ways to harness solar energy for useful applications in the field of energy and environment.In recent years,metal oxide-based tailored semiconductor photocatalysts have extensively been used for photocatalytic conversion of carbon dioxide(CO_(2))into fuels and other useful products utilizing solar energy.This is very significant not only from renewable energy consumption but also from reducing global warming point of view.Such current research activities are promising for a better future of society.The present mini-review is focused on recent developments(2–3 years)in metal oxide semiconductor hybrid photocatalysts-based photo-electrochemical conversion of CO_(2)into fuels and other useful products.First,general mechanism of photo-electrochemical conversion of CO_(2)into fuels or other useful products has been discussed.Then,various metal oxide-based emerging hybrid photocatalysts including tailoring of their morphological,compositional,and optoelectronic properties have been discussed with emphasis on their role in enhancing photoelectrochemical efficienty.Afterwards,mechanism of their photo-electrochemical reactions and applications in CO_(2)conversion into fuels/other useful products have been discussed.Finally,challenges and future prospects have been discussed followed by a summary.