Conventional titanium dioxide(TiO2)photocatalyst could absorb only ultraviolet light due to its wide bandgap.In this paper,black TiO2 with narrow bandgap was prepared by introducing oxygen vacancies.Meanwhile.nitrogen...Conventional titanium dioxide(TiO2)photocatalyst could absorb only ultraviolet light due to its wide bandgap.In this paper,black TiO2 with narrow bandgap was prepared by introducing oxygen vacancies.Meanwhile.nitrogen(N)and sulfur(S)elements were doped to further broaden the visible light response range of TiOx(NS-BT),and then heterostructured N.S-doped black TiOz/g-C3Na(CN/NS-BT)was successfully constructed by easily accessible route.The formation of CN/NS-BT heteroiunction structure increased the generation and separation efficiency of photogenerated electron-hole pairs,as well as accelerated the transfer rate of the carriers.The as-prepared CN/NS-BT exhibited excellent photocatalytic performance towards the degradation of Rhodamine B(RhB)under visible light irradiation with satisfactory stability.The apparent reaction rate constant of CN/NS-BT(0.0079)was 15.8-fold higher than that of commercial P25(0.0005),The structure,morphology,chemical composition and optical properties of the as-prepared CN/NS-BT were characterized by various analytical methods,and possible photocatalytic enhancement mechanism was proposed.Overall,CN/NS-BT composites look promising as photocatalytic material for future environmental treatment.展开更多
Sulfur doped anatase TiO2 nanoparticles （3 nm- 12 nm） were synthesized by the reaction of titanium tetrachloride, water and sulfuric acid with addition of 3 M NaOH at room temperature. The electro-optical and photoc...Sulfur doped anatase TiO2 nanoparticles （3 nm- 12 nm） were synthesized by the reaction of titanium tetrachloride, water and sulfuric acid with addition of 3 M NaOH at room temperature. The electro-optical and photocatalytic properties of the synthesized sulfur doped TiO2 nanoparticles were studied along with Degussa commercial TiO2 particles （24 nm）. The results show that band gap of TiO2 particles decreases from 3.31 to 3.25 eV and for that of commercial TiO2 to 3.2 eV when the particle sizes increased from 3 nm to 12 nm with increase in sulfur doping. The results of the photocatalytic activity under UV and sun radiation show maximum phenol conversion at the particle size of 4 nm at 4.80% S-doping. Similar results are obtained using UV energy for both phenol conversion and conversion of CO2＋H2O in which formation of methanol, ethanol and proponal is observed. Production of methanol is also achieved on samples with a particle size of 8 and 12 nm and sulfur doping of 4.80% and 5.26%. For TiO2 particle of 4 nm without S doping, the production of methanol, ethanol and proponal was lower as compared to the S-doped particles. This is attributed to the combined electronic effect and band gap change, S dopant, specific surface area and the light source used.展开更多
Ordered metal oxides superstructures have attracted much more attention in the fields of fuel generation and environmental purification owing to their unique physiochemical characteristics such as large surface area, ...Ordered metal oxides superstructures have attracted much more attention in the fields of fuel generation and environmental purification owing to their unique physiochemical characteristics such as large surface area, fine pore structure, efficient electronic mobility, and good stability. Very recently, TiOmesocrystals（TMCs） having superstructures self-assembled by TiOnanoparticle building blocks, are of considerable interest in current research and application ranging from UV to visible light attributed to their efficient charge separation and superior photocatalytic activity. In this review, we describe the common procedures to prepare unique TMCs and overview of recent developments of TMCs during last 3 years, especially the structure-related or electronic-effected mechanism in photocatalytic reaction. Further, we introduce the characterization and fundamental properties of modified TMCs by the means of single-particle fluorescence microscopy for unraveling the charge transport and photocatalytic properties of individual TMCs and time-resolved diffuse reflectance spectroscopy（TDR） for monitoring the charge transfer dynamics. Finally, various aspects on TMCs are discussed for the future developments of energy and environmental fields.展开更多
Three types of TiO2 nanostructures were synthesized via a facile hydrolysis method at195 °C. Effects of the preparation method and doping with N and F on the crystal structure and photocatalytic performance of Ti...Three types of TiO2 nanostructures were synthesized via a facile hydrolysis method at195 °C. Effects of the preparation method and doping with N and F on the crystal structure and photocatalytic performance of TiO2 were investigated. The nanomaterials were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller porosimetry, ultraviolet–visible diffuse reflectance spectroscopy and fluorescent emission spectra. Their photo-catalytic activity was examined by the photodegradation of methylene blue in aqueous solution under both ultra-violet and visible light irradiation. The results show that nitrogen and fluorine co-doped anatase TiO2 had the characteristics of a smaller crystalline size, broader light absorption spectrum and lower charge recombination than pure TiO2. Most importantly, more efficient photocatalytic activity under both ultra-violet and visible light was observed. The obtained N–F-TiO2 nanomaterial shows considerable potential for water treatment under sunlight irradiation.展开更多
Nitrogen-doped titanium dioxide(N/TiO2)nanophotocatalysts were successfully synthesized in the presence of environmentally benign nitrogen dopant source,guanidinium chloride,by the sol-gel method.The effect of calcina...Nitrogen-doped titanium dioxide(N/TiO2)nanophotocatalysts were successfully synthesized in the presence of environmentally benign nitrogen dopant source,guanidinium chloride,by the sol-gel method.The effect of calcination temperature(300–600℃)on their physicochemical properties was investigated by means XRD,XPS,FESEM,HRTEM,Raman spectroscopy,UV-vis DRS,PL and BET.Moreover,their photocatalytic activities were evaluated against rhodamine B(RhB)degradation under direct sun light.Results showed that the crystal phase of spheroidal N/TiO2 nanoparticles was changed from anatase(300℃)to rutile(600℃)via an intermediate anatase/rutile(A/R)mixed phase(400–500℃),and the RhB photodegradation performance was increased with the decrease of the calcination temperature.Notably,N/TiO2 prepared at 400℃demonstrated the best degradation performance(99%)after 5 h irradiation.The enhanced performance with high photostability was mainly attributed to its higher surface area and pore volume,stronger light absorption,and lower recombination rate.Such nanomaterials have practical applications for environmental remediation.展开更多
基金Supported by the National Natural Science Foundation of China(No.51472106)the Natural Science Foundation of Jilin Province,China(Nos.20180101065JC,20190201129JC)+1 种基金the International Science and Technology Cooperation Project of Jilit Province,China(No.20200801059GH)the Industrial Technology Research and Development Project of Development and Reform Commission of Jilin Province,China(Nos.2019C045-3,2019C42-6)。
文摘Conventional titanium dioxide(TiO2)photocatalyst could absorb only ultraviolet light due to its wide bandgap.In this paper,black TiO2 with narrow bandgap was prepared by introducing oxygen vacancies.Meanwhile.nitrogen(N)and sulfur(S)elements were doped to further broaden the visible light response range of TiOx(NS-BT),and then heterostructured N.S-doped black TiOz/g-C3Na(CN/NS-BT)was successfully constructed by easily accessible route.The formation of CN/NS-BT heteroiunction structure increased the generation and separation efficiency of photogenerated electron-hole pairs,as well as accelerated the transfer rate of the carriers.The as-prepared CN/NS-BT exhibited excellent photocatalytic performance towards the degradation of Rhodamine B(RhB)under visible light irradiation with satisfactory stability.The apparent reaction rate constant of CN/NS-BT(0.0079)was 15.8-fold higher than that of commercial P25(0.0005),The structure,morphology,chemical composition and optical properties of the as-prepared CN/NS-BT were characterized by various analytical methods,and possible photocatalytic enhancement mechanism was proposed.Overall,CN/NS-BT composites look promising as photocatalytic material for future environmental treatment.
文摘Sulfur doped anatase TiO2 nanoparticles （3 nm- 12 nm） were synthesized by the reaction of titanium tetrachloride, water and sulfuric acid with addition of 3 M NaOH at room temperature. The electro-optical and photocatalytic properties of the synthesized sulfur doped TiO2 nanoparticles were studied along with Degussa commercial TiO2 particles （24 nm）. The results show that band gap of TiO2 particles decreases from 3.31 to 3.25 eV and for that of commercial TiO2 to 3.2 eV when the particle sizes increased from 3 nm to 12 nm with increase in sulfur doping. The results of the photocatalytic activity under UV and sun radiation show maximum phenol conversion at the particle size of 4 nm at 4.80% S-doping. Similar results are obtained using UV energy for both phenol conversion and conversion of CO2＋H2O in which formation of methanol, ethanol and proponal is observed. Production of methanol is also achieved on samples with a particle size of 8 and 12 nm and sulfur doping of 4.80% and 5.26%. For TiO2 particle of 4 nm without S doping, the production of methanol, ethanol and proponal was lower as compared to the S-doped particles. This is attributed to the combined electronic effect and band gap change, S dopant, specific surface area and the light source used.
基金supported by a grant-in-aid for Scientific Research (Project 25220806 and others) from the Ministry of Education,Culture,Sports,Science and Technology (MEXT) of the Japanese Government
文摘Ordered metal oxides superstructures have attracted much more attention in the fields of fuel generation and environmental purification owing to their unique physiochemical characteristics such as large surface area, fine pore structure, efficient electronic mobility, and good stability. Very recently, TiOmesocrystals（TMCs） having superstructures self-assembled by TiOnanoparticle building blocks, are of considerable interest in current research and application ranging from UV to visible light attributed to their efficient charge separation and superior photocatalytic activity. In this review, we describe the common procedures to prepare unique TMCs and overview of recent developments of TMCs during last 3 years, especially the structure-related or electronic-effected mechanism in photocatalytic reaction. Further, we introduce the characterization and fundamental properties of modified TMCs by the means of single-particle fluorescence microscopy for unraveling the charge transport and photocatalytic properties of individual TMCs and time-resolved diffuse reflectance spectroscopy（TDR） for monitoring the charge transfer dynamics. Finally, various aspects on TMCs are discussed for the future developments of energy and environmental fields.
基金financially supported by the Natural Science Foundation of China (No. 51376110)the Natural Science Foundation of Shandong Province (No. ZR2012BQ027)+2 种基金the Program for Youth Science and Technology Star Fund of Jinan (No. 20120123)the Excellent Young Scientist Foundation of Shandong Province (No. BS2011CL005)the Science Development Project of Shandong Provincial (No. 2014GGX104004)
文摘Three types of TiO2 nanostructures were synthesized via a facile hydrolysis method at195 °C. Effects of the preparation method and doping with N and F on the crystal structure and photocatalytic performance of TiO2 were investigated. The nanomaterials were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller porosimetry, ultraviolet–visible diffuse reflectance spectroscopy and fluorescent emission spectra. Their photo-catalytic activity was examined by the photodegradation of methylene blue in aqueous solution under both ultra-violet and visible light irradiation. The results show that nitrogen and fluorine co-doped anatase TiO2 had the characteristics of a smaller crystalline size, broader light absorption spectrum and lower charge recombination than pure TiO2. Most importantly, more efficient photocatalytic activity under both ultra-violet and visible light was observed. The obtained N–F-TiO2 nanomaterial shows considerable potential for water treatment under sunlight irradiation.
文摘Nitrogen-doped titanium dioxide(N/TiO2)nanophotocatalysts were successfully synthesized in the presence of environmentally benign nitrogen dopant source,guanidinium chloride,by the sol-gel method.The effect of calcination temperature(300–600℃)on their physicochemical properties was investigated by means XRD,XPS,FESEM,HRTEM,Raman spectroscopy,UV-vis DRS,PL and BET.Moreover,their photocatalytic activities were evaluated against rhodamine B(RhB)degradation under direct sun light.Results showed that the crystal phase of spheroidal N/TiO2 nanoparticles was changed from anatase(300℃)to rutile(600℃)via an intermediate anatase/rutile(A/R)mixed phase(400–500℃),and the RhB photodegradation performance was increased with the decrease of the calcination temperature.Notably,N/TiO2 prepared at 400℃demonstrated the best degradation performance(99%)after 5 h irradiation.The enhanced performance with high photostability was mainly attributed to its higher surface area and pore volume,stronger light absorption,and lower recombination rate.Such nanomaterials have practical applications for environmental remediation.
