Defect engineering in metal organic frameworks(MOFs)has captured significant attention in the field of photocatalysis.A series of UiO-66(Ce)(UiO=University of Oslo)MOFs with different contents of missing-linker defect...Defect engineering in metal organic frameworks(MOFs)has captured significant attention in the field of photocatalysis.A series of UiO-66(Ce)(UiO=University of Oslo)MOFs with different contents of missing-linker defects have been developed for the photocatalytic selective oxidation of benzylamine(BA)and thioanisole(TA)under visible light.The introduction of missing-linker defects promotes the formation of unsaturated Ce sites with a high Ce3+content.It also generates a high concentration of oxygen vacancies.In situ Fourier transform infrared spectroscopy(FTIR)results revealed that BA and TA molecules were activated on coordinatively unsaturated Ce sites via the H-N…Ce and the C-S…Ce interactions,respectively.Simulated in situ electron paramagnetic resonance(EPR)data indicate that O_(2) activation and reduction occur at coordinatively unsaturated Ce^(3+)sites to form·O_(2)^(-).This is accelerated by the Ce^(3+)/Ce^(4+)redox cycle associated with the photogenerated electrons.The corresponding photogenerated holes are involved in the deprotonation of the activated BA and TA.The most active sample exhibits 98.4%and 95.5%conversion rates for BA and TA oxidation.Mechanisms for the molecular activation are proposed at the molecular level.展开更多
Photocatalytic conversion of CO_(2)into fuels such as CO,CH_(4),and CH_(3)OH,is a promising approach for achieving carbon neutrality.Bismuth oxyhalides(BiOX,where X=Cl,Br,and I)are appropriate photocatalysts for this ...Photocatalytic conversion of CO_(2)into fuels such as CO,CH_(4),and CH_(3)OH,is a promising approach for achieving carbon neutrality.Bismuth oxyhalides(BiOX,where X=Cl,Br,and I)are appropriate photocatalysts for this purpose due to the merits of visible-light-active,efficient charge separation,and easy-to-modify crystal structure and surface properties.For practical applications,multiple strategies have been proposed to develop high-efficiency BiOX-based photocatalysts.This review summarizes the development of different approaches to prepare BiOX-based photocatalysts for efficient CO_(2)reduction.In the review,the fundamentals of photocatalytic CO_(2)reduction are introduced.Then,several widely used modification methods for BiOX photocatalysts are systematacially discussed,including heterojunction construction,introducing oxygen vacancies(OVs),Bi-enrichment,heteroatom-doping,and morphology design.Finally,the challenges and prospects in the design of future BiOX-based photocatalysis for efficient CO_(2)reduction are examined.展开更多
Photocatalysis has attracted worldwide attention due to its potential in solar energy conversion.As a ＂green＂ advanced oxidation technology, it has been extensively used for water disinfection and wastewater treatme...Photocatalysis has attracted worldwide attention due to its potential in solar energy conversion.As a ＂green＂ advanced oxidation technology, it has been extensively used for water disinfection and wastewater treatment. This article provides a review of the recent progress in solar energy-induced photocatalytic disinfection of bacteria, focusing on the development of highly efficient photocatalysts and their underlying mechanisms in bacterial inactivation. The photocatalysts are classified into Ti O2-based and non-Ti O2-based systems, as Ti O2 is the most investigated photocatalyst. The synthesis methods, modification strategies, bacterial disinfection activities and mechanisms of different types of photocatalysts are reviewed in detail.Emphasis is given to the modified Ti O2, including noble metal deposition, non-metal doping,dye sensitization and composite Ti O2, along with typical non-Ti O2-based photocatalysts for bacterial disinfection, including metal oxides, sulfides, bismuth metallates, graphene-based photocatalysts, carbon nitride-based photocatalysts and natural photocatalysts. A simple and versatile methodology by using a partition system combined with scavenging study is introduced to study the photocatalytic disinfection mechanisms in different photocatalytic systems. This review summarizes the current state of the work on photocatalytic disinfection of bacteria, and is expected to offer useful insights for the future development in the field.展开更多
A simple approach to enhance the photocatalytic activity of red phosphorus（P） was developed.A mechanical ball milling method was applied to reduce the size of red P and to deposit graphene quantum dots onto red P. T...A simple approach to enhance the photocatalytic activity of red phosphorus（P） was developed.A mechanical ball milling method was applied to reduce the size of red P and to deposit graphene quantum dots onto red P. The product was characterized by scanning electron microscopy, transmission electron microscopy, contact angle measurements, zeta-potential measurements, X-ray diffraction and UV–vis absorption spectroscopy. The product exhibited high visible-light-driven photocatalytic performance in the photodegradation of rhodamine B.展开更多
In recent years,nanostructured photocatalysts have become the research focus due to their immense potential application in environmental purification and energy conversion.The photocatalytic performance of photocataly...In recent years,nanostructured photocatalysts have become the research focus due to their immense potential application in environmental purification and energy conversion.The photocatalytic performance of photocatalysts is closely related to their synthesis methods.High-intensity ultrasound irradiation could provide a unique tool for fabrication of photocatalysts with novel nanostructures.Ultrasound induces acoustic cavitation which generates unique physicochemical conditions,e.g.,hot spot（5000℃）,high pressure of 100 MPa,fast rate of heat conduction（〉〉1×10^10℃·s^-1）.These unique physicochemical conditions allow for the synthesis of various nanostructured photocatalysts.This review summarized the recent development in fabrication of photocatalysts with special nanostructures and their applications.The typical sonochemical reactors and parameters in sonochemical synthesis are introduced and discussed.Sonochemically prepared structures including nano-/microspheres,one-dimensional（1D） nanorods,two-dimensional（2D） nanosheets（nanoflakes,nanosquares）,noble metal nanoparticle（NP）-deposited and element-doped photocatalysts are described and summarized.It is believed that sonication is a green methodology,and it holds greatpotential in the near future for nanostructured photocatalyst fabrication.展开更多
A novel lamellar feather-like CeO_(2) structure has been fabricated by using a triblock copolymer as the structure-directing agent.This material was characterized in detail by X-ray diffraction,scanning electron micro...A novel lamellar feather-like CeO_(2) structure has been fabricated by using a triblock copolymer as the structure-directing agent.This material was characterized in detail by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,X-ray photoelectron spectroscopy,and BET surface area measurements.Compared with conventional spherical shaped ceria prepared by ammonia gelation,the ceria feathers have superior ability to support nanosized platinum particles due to their special structure.The“skeletons”of ceria feathers can serve as an ideal host matrix to anchor the platinum particles.Furthermore,the inter-crossing pattern of the“skeletons”also acts as a partition to separate platinum particles,allowing the Pt nanoparticles(average diameter~6 nm)to be highly dispersed in the structure.The Pt/feather-like CeO_(2) catalyst exhibits high activity in the water gas shift reaction.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22272026 and 22272028)the 111 Project(No.D16008)Jinhong Bi thanks the Youth Talent Support Program of Fujian Province(No.00387077).
文摘Defect engineering in metal organic frameworks(MOFs)has captured significant attention in the field of photocatalysis.A series of UiO-66(Ce)(UiO=University of Oslo)MOFs with different contents of missing-linker defects have been developed for the photocatalytic selective oxidation of benzylamine(BA)and thioanisole(TA)under visible light.The introduction of missing-linker defects promotes the formation of unsaturated Ce sites with a high Ce3+content.It also generates a high concentration of oxygen vacancies.In situ Fourier transform infrared spectroscopy(FTIR)results revealed that BA and TA molecules were activated on coordinatively unsaturated Ce sites via the H-N…Ce and the C-S…Ce interactions,respectively.Simulated in situ electron paramagnetic resonance(EPR)data indicate that O_(2) activation and reduction occur at coordinatively unsaturated Ce^(3+)sites to form·O_(2)^(-).This is accelerated by the Ce^(3+)/Ce^(4+)redox cycle associated with the photogenerated electrons.The corresponding photogenerated holes are involved in the deprotonation of the activated BA and TA.The most active sample exhibits 98.4%and 95.5%conversion rates for BA and TA oxidation.Mechanisms for the molecular activation are proposed at the molecular level.
基金supported by the Research Grants Council of the Hong Kong Special Administrative Region(No.14307322)the Excellent Young Scientist Fund(Hongkong and Macao)from the National Natural Science Foundation of China(No.22222208)。
文摘Photocatalytic conversion of CO_(2)into fuels such as CO,CH_(4),and CH_(3)OH,is a promising approach for achieving carbon neutrality.Bismuth oxyhalides(BiOX,where X=Cl,Br,and I)are appropriate photocatalysts for this purpose due to the merits of visible-light-active,efficient charge separation,and easy-to-modify crystal structure and surface properties.For practical applications,multiple strategies have been proposed to develop high-efficiency BiOX-based photocatalysts.This review summarizes the development of different approaches to prepare BiOX-based photocatalysts for efficient CO_(2)reduction.In the review,the fundamentals of photocatalytic CO_(2)reduction are introduced.Then,several widely used modification methods for BiOX photocatalysts are systematacially discussed,including heterojunction construction,introducing oxygen vacancies(OVs),Bi-enrichment,heteroatom-doping,and morphology design.Finally,the challenges and prospects in the design of future BiOX-based photocatalysis for efficient CO_(2)reduction are examined.
基金supported by research grants from Research Grant Council (GRF 478611)Innovation and Technology Commission (ITS/237/13) of Hong Kong SAR Government.P.K.supported by CAS/SAFEA International Partnership Program for Creative Research Teams of Chinese Academy of Sciences, China
文摘Photocatalysis has attracted worldwide attention due to its potential in solar energy conversion.As a ＂green＂ advanced oxidation technology, it has been extensively used for water disinfection and wastewater treatment. This article provides a review of the recent progress in solar energy-induced photocatalytic disinfection of bacteria, focusing on the development of highly efficient photocatalysts and their underlying mechanisms in bacterial inactivation. The photocatalysts are classified into Ti O2-based and non-Ti O2-based systems, as Ti O2 is the most investigated photocatalyst. The synthesis methods, modification strategies, bacterial disinfection activities and mechanisms of different types of photocatalysts are reviewed in detail.Emphasis is given to the modified Ti O2, including noble metal deposition, non-metal doping,dye sensitization and composite Ti O2, along with typical non-Ti O2-based photocatalysts for bacterial disinfection, including metal oxides, sulfides, bismuth metallates, graphene-based photocatalysts, carbon nitride-based photocatalysts and natural photocatalysts. A simple and versatile methodology by using a partition system combined with scavenging study is introduced to study the photocatalytic disinfection mechanisms in different photocatalytic systems. This review summarizes the current state of the work on photocatalytic disinfection of bacteria, and is expected to offer useful insights for the future development in the field.
基金partially supported by grants from the Research Grants Council of Hong Kong (Nos. 404112 and T23-407/13-N)supported by the National Natural Science Foundation of China (No. 21173179)a grant from the Vice-Chancellor's One-off Discretionary Fund of The Chinese University of Hong Kong (No. VCF2014016)
文摘A simple approach to enhance the photocatalytic activity of red phosphorus（P） was developed.A mechanical ball milling method was applied to reduce the size of red P and to deposit graphene quantum dots onto red P. The product was characterized by scanning electron microscopy, transmission electron microscopy, contact angle measurements, zeta-potential measurements, X-ray diffraction and UV–vis absorption spectroscopy. The product exhibited high visible-light-driven photocatalytic performance in the photodegradation of rhodamine B.
基金financially supported by the National Natural Science Foundation of China (Nos.21567008 and 21263005)the Young Scientist Training Project of Jiangxi Province China (No.20122BCB23015)+2 种基金Jiangxi Province Natural Science Foundation (No.20133BAB21003)the Landing Project of Science and Technology of Colleges and Universities in Jiangxi Province (No.KJLD14046)Yuan Hang Gongcheng of Jiangxi Province (2014)
文摘In recent years,nanostructured photocatalysts have become the research focus due to their immense potential application in environmental purification and energy conversion.The photocatalytic performance of photocatalysts is closely related to their synthesis methods.High-intensity ultrasound irradiation could provide a unique tool for fabrication of photocatalysts with novel nanostructures.Ultrasound induces acoustic cavitation which generates unique physicochemical conditions,e.g.,hot spot（5000℃）,high pressure of 100 MPa,fast rate of heat conduction（〉〉1×10^10℃·s^-1）.These unique physicochemical conditions allow for the synthesis of various nanostructured photocatalysts.This review summarized the recent development in fabrication of photocatalysts with special nanostructures and their applications.The typical sonochemical reactors and parameters in sonochemical synthesis are introduced and discussed.Sonochemically prepared structures including nano-/microspheres,one-dimensional（1D） nanorods,two-dimensional（2D） nanosheets（nanoflakes,nanosquares）,noble metal nanoparticle（NP）-deposited and element-doped photocatalysts are described and summarized.It is believed that sonication is a green methodology,and it holds greatpotential in the near future for nanostructured photocatalyst fabrication.
基金This research was supported by a Strategic Investments Scheme administered by The Chinese University of Hong Kong.
文摘A novel lamellar feather-like CeO_(2) structure has been fabricated by using a triblock copolymer as the structure-directing agent.This material was characterized in detail by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,X-ray photoelectron spectroscopy,and BET surface area measurements.Compared with conventional spherical shaped ceria prepared by ammonia gelation,the ceria feathers have superior ability to support nanosized platinum particles due to their special structure.The“skeletons”of ceria feathers can serve as an ideal host matrix to anchor the platinum particles.Furthermore,the inter-crossing pattern of the“skeletons”also acts as a partition to separate platinum particles,allowing the Pt nanoparticles(average diameter~6 nm)to be highly dispersed in the structure.The Pt/feather-like CeO_(2) catalyst exhibits high activity in the water gas shift reaction.
