A series of novel Ni/CeO2-Al2O3composite catalysts were synthesized by one-step citric acid complex method. The as-synthesized catalysts were characterized by N2physical adsorption/desorption, X-ray diffraction(XRD), ...A series of novel Ni/CeO2-Al2O3composite catalysts were synthesized by one-step citric acid complex method. The as-synthesized catalysts were characterized by N2physical adsorption/desorption, X-ray diffraction(XRD), Fourier transform infrared(FT-IR) spectroscopy, hydrogen temperature-programmed reduction(H2-TPR), X-ray photoelectron spectroscopy(XPS) and thermogravimetry analysis(TGA). The effects of nickel content, calcination and reaction temperatures, gas hourly space velocity(GHSV) and inert gas dilution of N2on their performance of catalytic partial oxidation of methane(CPOM) were investigated. Catalytic activity test results show that the highest methane conversion(>85%), the best selectivities to carbon monoxide(>87%) and to hydrogen(>95%), the excellent stability and perfect H2/CO ratio(2.0) can be obtained over Ni/CeO2-Al2O3with 8 wt% Ni content calcined at 700 ℃ under the reaction condition of 750 ℃, CH4/O2ratio of 2 : 1 and gas hourly space velocity of 12000 mL h-1 g-1. Characterization results show that the good catalytic performance of this composite catalyst can be contributed to its large specific surface area(～108 m2 g-1), small crystallite size, easy reducibility and low coking rate.展开更多
A series of La/Ce-codoped Bi_2O_3 composite photocatalysts were fabricated via hydrothermal–calcination process. The as-prepared products were intensively characterized by some physicochemical characterizations like ...A series of La/Ce-codoped Bi_2O_3 composite photocatalysts were fabricated via hydrothermal–calcination process. The as-prepared products were intensively characterized by some physicochemical characterizations like N_2 physical adsorption, X-ray powder diffraction(XRD), scanning electron microscope(SEM), transmission electron microscope(TEM), UV–Vis diffuse reflectance(UV–Vis DRS), Fourier transform infrared spectroscopy(FT-IR),photoelectrochemical measurements, and photoluminescence(PL) spectroscopy. The characterization results indicated that La and Ce doping induced obvious crystal phase transformation in Bi_2O_3, from monoclinic to tetragonal phase. La and Ce codoping also gave rise to the obvious synergetic effects, e.g., the lattice contraction of Bi_2O_3, the decrease of crystal size and the increase of surface area. The photocatalytic performance of the prepared catalysts was evaluated by removal of dye acid orange II with high concentration under visible light irradiation. Results showed that La/Ce-codoped Bi_2O_3 displayed much higher photocatalytic performance than that of bare Bi_2O_3, single La or Ce doped Bi_2O_3 samples. The superior photocatalytic activity was mainly attributed to the improved texture and surface properties and the synergistic effects of La and Ce codoping on suppressing the recombination of photo-generated electrons(e^-) and holes(h^+).展开更多
The design of the photocatalytic materials has made a great of remarkable progress in the area of the enhancement photocatalytic activity,but there are still lots of problems such as wide band gap,low utilization of s...The design of the photocatalytic materials has made a great of remarkable progress in the area of the enhancement photocatalytic activity,but there are still lots of problems such as wide band gap,low utilization of sunlight,low quantum efficiency and poor stability,which further limit the extensive practical applications.Thus,it is a hot research topic and key scientific problem to be solved that how to design and prepare the catalysts,which can respond to visible and near-infrared light in sunlight.Inspired by efficient nonlinear optical upconversion materials,upconversion-based nanocomposites can indirectly broaden the absorption ranges of semiconductors by co nverting the captured long-band visible and near-infrared incident light into high-energy short-band visible or ultraviolet light,which can be adopted as the promising candidate in wide-spectral-light-activating photocatalytic materials coupling with conventional semiconductors.According to our recent works and literature reports,recent review summarizes the research progress of photocatalytic materials with upconversion effect on photolysis of water for hydrogen production,degradation of organic and inorganic pollutants,reduction of CO_(2) and photodynamic therapy.The prepared nanocomposites can suppress the recombination of electrons and holes,and greatly improve the photocatalytic efficiency by the synergistic effect.It maybe stimulates a great interest in rational design and preparation of efficient full-spectrum photocatalytic systems and their wide application in solar energy conversion.展开更多
基金supported by the National Natural Science Foundation of China(Grants No.21067004 and No.21263005)the Technological Foundation of Jiangxi Province Education Office(No.GJJ12344)+1 种基金the Young Science and Technolgy Project of Jiangxi Province(No.20133BAB21003)the Young Scientist Training Project of Jiangxi Province(No.20122BCB23015)
文摘A series of novel Ni/CeO2-Al2O3composite catalysts were synthesized by one-step citric acid complex method. The as-synthesized catalysts were characterized by N2physical adsorption/desorption, X-ray diffraction(XRD), Fourier transform infrared(FT-IR) spectroscopy, hydrogen temperature-programmed reduction(H2-TPR), X-ray photoelectron spectroscopy(XPS) and thermogravimetry analysis(TGA). The effects of nickel content, calcination and reaction temperatures, gas hourly space velocity(GHSV) and inert gas dilution of N2on their performance of catalytic partial oxidation of methane(CPOM) were investigated. Catalytic activity test results show that the highest methane conversion(>85%), the best selectivities to carbon monoxide(>87%) and to hydrogen(>95%), the excellent stability and perfect H2/CO ratio(2.0) can be obtained over Ni/CeO2-Al2O3with 8 wt% Ni content calcined at 700 ℃ under the reaction condition of 750 ℃, CH4/O2ratio of 2 : 1 and gas hourly space velocity of 12000 mL h-1 g-1. Characterization results show that the good catalytic performance of this composite catalyst can be contributed to its large specific surface area(～108 m2 g-1), small crystallite size, easy reducibility and low coking rate.
基金supported by the National Natural Science Foundation of China (Nos. 21567008, 21607064, 21263005)the Natural Science Foundation of Jiangxi Province (No. 20161BAB203090)the Program of Qingjiang Excellent Young Talents, Jiangxi University of Science and Technology,the Landing Project of Science and Technology of Colleges and Universities in Jiangxi Province China (No. KJLD14046)
文摘A series of La/Ce-codoped Bi_2O_3 composite photocatalysts were fabricated via hydrothermal–calcination process. The as-prepared products were intensively characterized by some physicochemical characterizations like N_2 physical adsorption, X-ray powder diffraction(XRD), scanning electron microscope(SEM), transmission electron microscope(TEM), UV–Vis diffuse reflectance(UV–Vis DRS), Fourier transform infrared spectroscopy(FT-IR),photoelectrochemical measurements, and photoluminescence(PL) spectroscopy. The characterization results indicated that La and Ce doping induced obvious crystal phase transformation in Bi_2O_3, from monoclinic to tetragonal phase. La and Ce codoping also gave rise to the obvious synergetic effects, e.g., the lattice contraction of Bi_2O_3, the decrease of crystal size and the increase of surface area. The photocatalytic performance of the prepared catalysts was evaluated by removal of dye acid orange II with high concentration under visible light irradiation. Results showed that La/Ce-codoped Bi_2O_3 displayed much higher photocatalytic performance than that of bare Bi_2O_3, single La or Ce doped Bi_2O_3 samples. The superior photocatalytic activity was mainly attributed to the improved texture and surface properties and the synergistic effects of La and Ce codoping on suppressing the recombination of photo-generated electrons(e^-) and holes(h^+).
基金Project supported by the National Natural Science Foundation of China(21962006,21707055,21872030)Youth Key Project of Jiangxi Province Natural Science Foundation(20192ACBL21011)+6 种基金Program of Qingjiang Excellent Young Talents of Jiangxi University of Science and Technology(3401223429)Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(2019)Guangdong Basic and Applied Basic Research Foundation(2019A1515011249)Key Research Project of Natural Science of Guangdong Provincial Department of Education(2019)Jiangxi Province Natural Science Foundation(20181BAB213010)Open Fund of Guangdong Provincial Key Laboratory of Petrochemical Pollution Process and Control(2018B030322017)Open Fund for Key Laboratory of Green Energy and Environmental Catalysis in Universities of Fujian Province(FJ-GEEC201901)。
文摘The design of the photocatalytic materials has made a great of remarkable progress in the area of the enhancement photocatalytic activity,but there are still lots of problems such as wide band gap,low utilization of sunlight,low quantum efficiency and poor stability,which further limit the extensive practical applications.Thus,it is a hot research topic and key scientific problem to be solved that how to design and prepare the catalysts,which can respond to visible and near-infrared light in sunlight.Inspired by efficient nonlinear optical upconversion materials,upconversion-based nanocomposites can indirectly broaden the absorption ranges of semiconductors by co nverting the captured long-band visible and near-infrared incident light into high-energy short-band visible or ultraviolet light,which can be adopted as the promising candidate in wide-spectral-light-activating photocatalytic materials coupling with conventional semiconductors.According to our recent works and literature reports,recent review summarizes the research progress of photocatalytic materials with upconversion effect on photolysis of water for hydrogen production,degradation of organic and inorganic pollutants,reduction of CO_(2) and photodynamic therapy.The prepared nanocomposites can suppress the recombination of electrons and holes,and greatly improve the photocatalytic efficiency by the synergistic effect.It maybe stimulates a great interest in rational design and preparation of efficient full-spectrum photocatalytic systems and their wide application in solar energy conversion.
