Poly(methyl methacrylate)-titania(PMMA-TiO 2) nanocomposites were synthesized from tetrabutyl titanate(TBT) and methyl methacrylate(MMA) by sol-gel process using methacryloyloxypropyl trimethoxy siliane(MPTMS) as coup...Poly(methyl methacrylate)-titania(PMMA-TiO 2) nanocomposites were synthesized from tetrabutyl titanate(TBT) and methyl methacrylate(MMA) by sol-gel process using methacryloyloxypropyl trimethoxy siliane(MPTMS) as coupling agent and dilute hydrochloric acid as catalyst. Reaction parameters affecting the character of the products, such as the concentration of HCl, amount of water and coupling agent were discussed. The results showed that considerable good product can be obtained when the concentration of HCl is (0.3±0.02) mol/L, n(TBT)∶n(H 2O)>5∶1 and n(MPTMS)/n(TBT)>1. The chemical structure of PMMA-TiO 2 was characterized by IR, TEM and TG/DTA.展开更多
TiO2‐based Z‐scheme photocatalysts have attracted considerable attention because of the low recombination rate of their photogenerated electron–hole pairs and their high photocatalytic efficiency.In this review,the...TiO2‐based Z‐scheme photocatalysts have attracted considerable attention because of the low recombination rate of their photogenerated electron–hole pairs and their high photocatalytic efficiency.In this review,the reaction mechanism of Z‐scheme photocatalysts,recent research progress in the application of TiO2‐based Z‐scheme photocatalysts,and improved methods for photocatalytic performance enhancement are explored.Their applications,including water splitting,CO2reduction,decomposition of volatile organic compounds,and degradation of organic pollutants,are also described.The main factors affecting the photocatalytic performance of TiO2‐based Z‐scheme photocatalysts,such as pH,conductive medium,cocatalyst,architecture,and mass ratio,are discussed.Concluding remarks are presented,and some suggestions for the future development of TiO2‐based Z‐scheme photocatalysts are highlighted.展开更多
N-F-codoped TiO2 （NFTO） photocatalysts were synthesized by a simple sol-gel process with tetrabutyl titanate （Ti（OBu）4 ） as the precursor of TiO 2 and ammonium fluoride （NH4 F） as the source of N and F.The syn...N-F-codoped TiO2 （NFTO） photocatalysts were synthesized by a simple sol-gel process with tetrabutyl titanate （Ti（OBu）4 ） as the precursor of TiO 2 and ammonium fluoride （NH4 F） as the source of N and F.The synthesized photocatalysts were investigated by X- ray diffraction （XRD）,X-ray photoelectron spectroscopy （XPS）,ultraviolet-visible diffuse reflectance spectroscopy （UV-Vis DRS） and photodegradation reaction tests of 4-chlorophenol under visible light irradiation to understand the relationship between the structure of NFTO catalyst and corresponding photocatalytic activity.The crystal phase and particle size of catalysts were found to be largely affected by the calcination temperature.In addition,N-F-codoping could inhibit phase transition of TiO2 from anatase to rutile.The presence of N and F atoms in the lattice of TiO2 is responsible for the visible light catalytic activity.In UV-Vis DRS tests,the spectrum of NFTO exhibited red shift compared with Degussa P25 and the band gap was reduced to around 2.92 eV.Under optimal calcination temperature and dopant concentration conditions,the NFTO photocatalyst exhibited the highest activity in the photodegradation reaction tests of 4-chlorophenol under visible light irradiation with a degradation rate of 75.84%.Besides,the 5-recycle test showed that NFTO photocatalyst could be reused and its activity kept stable under visible light irradiation.展开更多
Polyaniline （PAn） sensitized nanocrystalline TiO2 composites （TiO2/PAn） were successfully prepared and used as an efficient photocatalyst for the degradation of dye methylene blue （MB）. The results showed that P...Polyaniline （PAn） sensitized nanocrystalline TiO2 composites （TiO2/PAn） were successfully prepared and used as an efficient photocatalyst for the degradation of dye methylene blue （MB）. The results showed that PAn was able to sensitize TiO2 efficiently and the composite photocatalyst could be activated by absorbing both the ultraviolet and visible light （λ： 190 ～ 800 nm）, whereas pure TiO2 absorbed ultraviolet light only （λ 〈 380 nm）. Under the irradiation of natural light, MB could be degraded more efficiently on the TiO2/PAn composites than on the TiO2 Furthermore, it could be easily separated from the solution by simple sedimentation.展开更多
TiO2 and montmorillonite composite photocatalysts were prepared and applied in degrading γ-hexachlorocyclohexane （γ-HCH） in soils. After being spiked with γ-HCH, soil samples loaded with the composite photocataly...TiO2 and montmorillonite composite photocatalysts were prepared and applied in degrading γ-hexachlorocyclohexane （γ-HCH） in soils. After being spiked with γ-HCH, soil samples loaded with the composite photocatalysts were exposed to UV-light irradiation. The results indicated that the photocatalytic activities of the composite photocatalysts varied with the content of TiO2 in the order of 10%〈70%〈50% 〈30%, Moreover, the photocatalytic activity of the composite photocatalysts with TiO2 content 30% was higher than that of the pure P25 with the same mass of TiO2. The strong adsorption capacity of the composite photocatalysts and quantum size effect may contribute to its increased photocatalytic activities. In addition, effect of dosage of composite photocatalysts and soil pH on γ-HCH photodegradation was investigated. Pentachlorocyclohexene, trichlorocyclohexene, and dichlorobenzene were detected as photodegradation intermediates, which were gradually degraded with the photodegradation evolution.展开更多
文摘Poly(methyl methacrylate)-titania(PMMA-TiO 2) nanocomposites were synthesized from tetrabutyl titanate(TBT) and methyl methacrylate(MMA) by sol-gel process using methacryloyloxypropyl trimethoxy siliane(MPTMS) as coupling agent and dilute hydrochloric acid as catalyst. Reaction parameters affecting the character of the products, such as the concentration of HCl, amount of water and coupling agent were discussed. The results showed that considerable good product can be obtained when the concentration of HCl is (0.3±0.02) mol/L, n(TBT)∶n(H 2O)>5∶1 and n(MPTMS)/n(TBT)>1. The chemical structure of PMMA-TiO 2 was characterized by IR, TEM and TG/DTA.
基金supported by the National Natural Science Foundation of China(51602207,21433007,51320105001,21573170)the Self-determined and Innovative Research Funds of SKLWUT(2017-ZD-4,2016-KF-17)the Natural Science Foundation of Hubei Province of China(2015CFA001)~~
文摘TiO2‐based Z‐scheme photocatalysts have attracted considerable attention because of the low recombination rate of their photogenerated electron–hole pairs and their high photocatalytic efficiency.In this review,the reaction mechanism of Z‐scheme photocatalysts,recent research progress in the application of TiO2‐based Z‐scheme photocatalysts,and improved methods for photocatalytic performance enhancement are explored.Their applications,including water splitting,CO2reduction,decomposition of volatile organic compounds,and degradation of organic pollutants,are also described.The main factors affecting the photocatalytic performance of TiO2‐based Z‐scheme photocatalysts,such as pH,conductive medium,cocatalyst,architecture,and mass ratio,are discussed.Concluding remarks are presented,and some suggestions for the future development of TiO2‐based Z‐scheme photocatalysts are highlighted.
基金supported by the Scienceand Technology Project of Education Commission of Chongqing of China(No.KJ110709)the Key Science Project of Ministry of Education of China(No.2008119)+1 种基金the Colleges and Universities Innovation Team Project of Chongqing of China(No.KJTD201020)the Scienceand Technology Project of Engineering Research Centre for Waste Oil,Ministry of Education of China(No.FYKJ2009012)
文摘N-F-codoped TiO2 （NFTO） photocatalysts were synthesized by a simple sol-gel process with tetrabutyl titanate （Ti（OBu）4 ） as the precursor of TiO 2 and ammonium fluoride （NH4 F） as the source of N and F.The synthesized photocatalysts were investigated by X- ray diffraction （XRD）,X-ray photoelectron spectroscopy （XPS）,ultraviolet-visible diffuse reflectance spectroscopy （UV-Vis DRS） and photodegradation reaction tests of 4-chlorophenol under visible light irradiation to understand the relationship between the structure of NFTO catalyst and corresponding photocatalytic activity.The crystal phase and particle size of catalysts were found to be largely affected by the calcination temperature.In addition,N-F-codoping could inhibit phase transition of TiO2 from anatase to rutile.The presence of N and F atoms in the lattice of TiO2 is responsible for the visible light catalytic activity.In UV-Vis DRS tests,the spectrum of NFTO exhibited red shift compared with Degussa P25 and the band gap was reduced to around 2.92 eV.Under optimal calcination temperature and dopant concentration conditions,the NFTO photocatalyst exhibited the highest activity in the photodegradation reaction tests of 4-chlorophenol under visible light irradiation with a degradation rate of 75.84%.Besides,the 5-recycle test showed that NFTO photocatalyst could be reused and its activity kept stable under visible light irradiation.
文摘Polyaniline （PAn） sensitized nanocrystalline TiO2 composites （TiO2/PAn） were successfully prepared and used as an efficient photocatalyst for the degradation of dye methylene blue （MB）. The results showed that PAn was able to sensitize TiO2 efficiently and the composite photocatalyst could be activated by absorbing both the ultraviolet and visible light （λ： 190 ～ 800 nm）, whereas pure TiO2 absorbed ultraviolet light only （λ 〈 380 nm）. Under the irradiation of natural light, MB could be degraded more efficiently on the TiO2/PAn composites than on the TiO2 Furthermore, it could be easily separated from the solution by simple sedimentation.
基金Project supported by the National Natural Science Foundation of China(No. 29977003, 20507011)the State Ministry of Education of China(No. 00028)
文摘TiO2 and montmorillonite composite photocatalysts were prepared and applied in degrading γ-hexachlorocyclohexane （γ-HCH） in soils. After being spiked with γ-HCH, soil samples loaded with the composite photocatalysts were exposed to UV-light irradiation. The results indicated that the photocatalytic activities of the composite photocatalysts varied with the content of TiO2 in the order of 10%〈70%〈50% 〈30%, Moreover, the photocatalytic activity of the composite photocatalysts with TiO2 content 30% was higher than that of the pure P25 with the same mass of TiO2. The strong adsorption capacity of the composite photocatalysts and quantum size effect may contribute to its increased photocatalytic activities. In addition, effect of dosage of composite photocatalysts and soil pH on γ-HCH photodegradation was investigated. Pentachlorocyclohexene, trichlorocyclohexene, and dichlorobenzene were detected as photodegradation intermediates, which were gradually degraded with the photodegradation evolution.
