Most of TiO_(2) particles can be used as a photocatalyst for the selective oxidation of cyclohexane under ultraviolet light illumination.In this paper,Ti^(3+) self-doped TiO_(2) submicron-sized particles(i.e.,Ti^(3+)/...Most of TiO_(2) particles can be used as a photocatalyst for the selective oxidation of cyclohexane under ultraviolet light illumination.In this paper,Ti^(3+) self-doped TiO_(2) submicron-sized particles(i.e.,Ti^(3+)/TiO_(2) SMP)were used as a catalyst for visible-light driven photocatalytic cyclohexane oxidation.The microstructure and properties of the Ti^(3+)/TiO_(2) SMP were characterized by X-ray diffraction(XRD),UVevisible diffuse reflection(UVeVis DRS),scanning electron microscopy(SEM),electron paramagnetic resonance(EPR),solid-state photoluminescence spectroscopy(PLS)and X-ray photoelectron spectroscopy(XPS).The Ti^(3+)/TiO_(2) SMP exhibits good visible-light driven photocatalytic performances for cyclohexane oxidation with cyclohexanone as a dominate product.Effects of solvent,reaction temperature,reaction time and oxygen pressure on the formation of cyclohexanone were investigated.The cyclohexane oxidation over the Ti^(3+)/TiO_(2) SMP photocatalyst using carbon tetrachloride as a solvent under the optimal conditions presents a greater selectivity to cyclohexane(i.e.,95.1%).Based on the controlled experimental results with different radical scavengers,the hole(h^(+))is critical for the activation of cyclohexane.展开更多
As an effective way to enhance the photo/electrocatalytic performance of titanium dioxide(TiO_(2))is to explore the positive roles of doped fluorine sites in the fluorinated TiO_(2)systems,which,currently still lacks ...As an effective way to enhance the photo/electrocatalytic performance of titanium dioxide(TiO_(2))is to explore the positive roles of doped fluorine sites in the fluorinated TiO_(2)systems,which,currently still lacks the direct experimental evidence due to the complexity of the species involved.Herein,we have fabricated TiOF_(2)/TiO_(2)with interfacial bridging fluorine(Ti2-F)via a coherent phase transition through hydrothermal synthesis.Nuclear magnetic resonance and electron paramagnetic resonance characterization have provided strong evidence of the transformation of the doped fluorine from Ti2-F to Ti1-F and the subsequent generation of Ti^(3+)at the interface of the TiOF_(2)and TiO_(2)under UV-visible(UV-vis)light irradiation.Density functional theory(DFT)calculations and photo/electrochemical measurements further confirmed the electron donor behavior of the Ti^(3+).The benefit is a significantly enhanced charge transfer efficiency in TiOF_(2)/TiO_(2),which not only resulted in improved performances for the photodegradation of acetone being 5.5 times higher than the commercial TiO_(2)but also supported high capacity for sodium-ion storage.Thus,the TiOF_(2)/TiO_(2)with Ti2-F provided a perfect structure to investigate the roles of fluorine sites in fluorinated TiO_(2)systems and their interaction with material properties.展开更多
Electrosynthesis of hydrogen peroxide(H2O_(2)),as a sustainable alternative to the anthraquinone oxidation method,provides the feasibility of directly generating H_(2)O_(2).Here,we report Cu-doped TiO_(2) as an effici...Electrosynthesis of hydrogen peroxide(H2O_(2)),as a sustainable alternative to the anthraquinone oxidation method,provides the feasibility of directly generating H_(2)O_(2).Here,we report Cu-doped TiO_(2) as an efficient electrocatalyst which exhibits the excellent two-electron oxygen reduction reaction(2e-ORR)performance with respect to the pristine TiO_(2).The Cu doping results in the distortion of TiO_(2) lattice and further forms a large number of oxygen vacancies and Ti^(3+).Such Cu-doped TiO_(2) exhibits a positive onset potential about 0.79 V and high H_(2)O_(2) selectivity about 91.2%.Moreover,it also shows a larger H_(2)O_(2) yield and good stability.Density functional theory(DFT)calculations reveal that Cu dopant not only improves the electrical conductivity of pristine TiO_(2) but reduces the*OOH adsorption energy of active sites,which is beneficial to promote subsequently 2e-ORR process.展开更多
Semiconductor photocatalysis is one of the most widely used environment-friendly technologies for removing various contaminants.As a well-developed photocatalyst,titanium dioxide(TiO_(2))still has limits in its wide b...Semiconductor photocatalysis is one of the most widely used environment-friendly technologies for removing various contaminants.As a well-developed photocatalyst,titanium dioxide(TiO_(2))still has limits in its wide bandgap and rapid recombination rate of photogenerated charge carriers.Recently,black TiO_(2)appears as a strong candidate in the improvement of sunlight harvesting,because of its excellent absorption capacity and utilization of solar radiation.Despite extensive applications in both environmental and energy fields,the use of black TiO_(2)as a photocatalyst in pollutant removal is ambiguous.The primary objective of the review is to comprehensively evaluate the applications of black TiO_(2)in photocatalytic removal of contaminants,including conventional organic contaminants,emerging contaminants,microbes,and heavy metals.The basic properties,photocatalytic mechanism,and synthesis of black TiO_(2)have been summarized and analyzed.Moreover,the stability and recoverability of black TiO_(2)have also been discussed.Finally,the perspectives of the application of black TiO_(2)in pollutant removal have been further discussed.展开更多
基金the support of this work by National Key Research and Development Plan(Grant No.2016YFC0303704)the National Natural Science Foundation of China(Grant No.21676296).
文摘Most of TiO_(2) particles can be used as a photocatalyst for the selective oxidation of cyclohexane under ultraviolet light illumination.In this paper,Ti^(3+) self-doped TiO_(2) submicron-sized particles(i.e.,Ti^(3+)/TiO_(2) SMP)were used as a catalyst for visible-light driven photocatalytic cyclohexane oxidation.The microstructure and properties of the Ti^(3+)/TiO_(2) SMP were characterized by X-ray diffraction(XRD),UVevisible diffuse reflection(UVeVis DRS),scanning electron microscopy(SEM),electron paramagnetic resonance(EPR),solid-state photoluminescence spectroscopy(PLS)and X-ray photoelectron spectroscopy(XPS).The Ti^(3+)/TiO_(2) SMP exhibits good visible-light driven photocatalytic performances for cyclohexane oxidation with cyclohexanone as a dominate product.Effects of solvent,reaction temperature,reaction time and oxygen pressure on the formation of cyclohexanone were investigated.The cyclohexane oxidation over the Ti^(3+)/TiO_(2) SMP photocatalyst using carbon tetrachloride as a solvent under the optimal conditions presents a greater selectivity to cyclohexane(i.e.,95.1%).Based on the controlled experimental results with different radical scavengers,the hole(h^(+))is critical for the activation of cyclohexane.
基金the National Key R&D Program of China(no.2017YFC1103800)the Program for Changjiang Scholars and Innovative Research Team in University(no.IRT_15R52)+7 种基金the joint National Natural Science Foundation of China-Deutsche Forschungsgemeinschaft(NSFCDFG)project(NSFC grant no.51861135313 and DFG no.JA466/39-1)the China Postdoctoral Science Foundation(no.2020M672961)the International Science and Technology Cooperation Program of China(no.2015DFE52870)the Fundamental Research Funds for the Central Universities(nos.19lgpy113 and 19lgzd16)the Science and Technology Research Project of Hubei Province Department of Education(no.D20191001)Jilin Province Science and Technology Development Plan(no.20180101208JC)the National 111 project(no.B20002)Ministry of Science and Technology and Ministry of Education,China.
文摘As an effective way to enhance the photo/electrocatalytic performance of titanium dioxide(TiO_(2))is to explore the positive roles of doped fluorine sites in the fluorinated TiO_(2)systems,which,currently still lacks the direct experimental evidence due to the complexity of the species involved.Herein,we have fabricated TiOF_(2)/TiO_(2)with interfacial bridging fluorine(Ti2-F)via a coherent phase transition through hydrothermal synthesis.Nuclear magnetic resonance and electron paramagnetic resonance characterization have provided strong evidence of the transformation of the doped fluorine from Ti2-F to Ti1-F and the subsequent generation of Ti^(3+)at the interface of the TiOF_(2)and TiO_(2)under UV-visible(UV-vis)light irradiation.Density functional theory(DFT)calculations and photo/electrochemical measurements further confirmed the electron donor behavior of the Ti^(3+).The benefit is a significantly enhanced charge transfer efficiency in TiOF_(2)/TiO_(2),which not only resulted in improved performances for the photodegradation of acetone being 5.5 times higher than the commercial TiO_(2)but also supported high capacity for sodium-ion storage.Thus,the TiOF_(2)/TiO_(2)with Ti2-F provided a perfect structure to investigate the roles of fluorine sites in fluorinated TiO_(2)systems and their interaction with material properties.
基金This work was supported by the National Natural ScienceFoundation of China (No. 22072015).
文摘Electrosynthesis of hydrogen peroxide(H2O_(2)),as a sustainable alternative to the anthraquinone oxidation method,provides the feasibility of directly generating H_(2)O_(2).Here,we report Cu-doped TiO_(2) as an efficient electrocatalyst which exhibits the excellent two-electron oxygen reduction reaction(2e-ORR)performance with respect to the pristine TiO_(2).The Cu doping results in the distortion of TiO_(2) lattice and further forms a large number of oxygen vacancies and Ti^(3+).Such Cu-doped TiO_(2) exhibits a positive onset potential about 0.79 V and high H_(2)O_(2) selectivity about 91.2%.Moreover,it also shows a larger H_(2)O_(2) yield and good stability.Density functional theory(DFT)calculations reveal that Cu dopant not only improves the electrical conductivity of pristine TiO_(2) but reduces the*OOH adsorption energy of active sites,which is beneficial to promote subsequently 2e-ORR process.
基金supported by the National Key Research and Development Plan(Nos.2016YFC0502800)Natural Science Foundation(No.U2040212,51779008)+1 种基金MWR/CAS Institute of Hydroecology(No.1440020035)the Natural Science and Engineering Research Council of Canada。
文摘Semiconductor photocatalysis is one of the most widely used environment-friendly technologies for removing various contaminants.As a well-developed photocatalyst,titanium dioxide(TiO_(2))still has limits in its wide bandgap and rapid recombination rate of photogenerated charge carriers.Recently,black TiO_(2)appears as a strong candidate in the improvement of sunlight harvesting,because of its excellent absorption capacity and utilization of solar radiation.Despite extensive applications in both environmental and energy fields,the use of black TiO_(2)as a photocatalyst in pollutant removal is ambiguous.The primary objective of the review is to comprehensively evaluate the applications of black TiO_(2)in photocatalytic removal of contaminants,including conventional organic contaminants,emerging contaminants,microbes,and heavy metals.The basic properties,photocatalytic mechanism,and synthesis of black TiO_(2)have been summarized and analyzed.Moreover,the stability and recoverability of black TiO_(2)have also been discussed.Finally,the perspectives of the application of black TiO_(2)in pollutant removal have been further discussed.
