Catalyst support is extremely important for future fuel cell devices.In this work,we developed doubleshelled C/TiO2(DSCT)hollow spheres as an excellent catalyst support via a template-directed method.The combination o...Catalyst support is extremely important for future fuel cell devices.In this work,we developed doubleshelled C/TiO2(DSCT)hollow spheres as an excellent catalyst support via a template-directed method.The combination of hollow structure,TiO2 shell and carbon layer results in excellent electron conductivity,electrocatalytic activity,and chemical stability.These uniformed DSCT hollow spheres are used as catalyst support to synthesize Pt/DSCT hollow spheres electrocatalyst.The resulting Pt/DSCT hollow spheres exhibited high catalytic performance with a current density of 462 mA mg^-1 for methanol oxidation reaction,which is 2.52 times higher than that of the commercial Pt/C.Furthermore,the increased tolerance to carbonaceous poisoning with a higher If/Ibratio and a better long-term stability in acid media suggests that the DSCT hollow sphere is a promising C/TiO2-based catalyst support for direct methanol fuel cells applications.展开更多
Great efforts have been devoted to improve the photocatalytic activity of TiO2 in the visible light region. Rational design of the external structure and adjustment of intrinsic electronic status by impurity doping ar...Great efforts have been devoted to improve the photocatalytic activity of TiO2 in the visible light region. Rational design of the external structure and adjustment of intrinsic electronic status by impurity doping are two main effective ways to achieve this purpose. A facile onepot synthetic approach was developed to prepare C-doped hollow TiO2 spheres, which simultaneously realized these advantages. The synthesized TiO2 exhibits a mesoporous hollow spherical structure composed of fine nanocrystals, leading to high specific surface area（~180 m^2/g） and versatile porous texture. Carbonate-doping was achieved by a postthermal treatment at a relatively low temperature（200°C）, which makes the absorption edge red-shifted to the visible region of the solar spectrum. Concomitantly, Ti^（3＋） induced by C-doping also functions in improving the visible-light photocatalytic activity by reducing the band gap. There exists a synergistic effect from multiple stimulatives to enhance the photocatalytic effect of the prepared TiO2 catalyst. It is not out of expectation that the asprepared C-doped hollow TiO2 spheres exhibits an improved photocatalytic activity under visible light irradiation in organic pollutant degradation.展开更多
A high purity sheet-like Na2Ti307 material was synthesized by a new facile solid-state method with hollow sphere TiO2 as titanium source. X-Ray diffraction（XRD） measurement proves that no impurity phase existed when...A high purity sheet-like Na2Ti307 material was synthesized by a new facile solid-state method with hollow sphere TiO2 as titanium source. X-Ray diffraction（XRD） measurement proves that no impurity phase existed when the sample was heated at 900 ℃. Charge/discharge measurement was performed in a potential range of 0.01m2.5 V at different current-rates（C-rates）. The initial charge/discharge capacities are 191/424 mA.h/g at 0.1 C and still remain as high as 101 mA.h/g after 50 cycles. CV test proves that the large irreversible capacity in the initial cycle results from the formation of the solid electrolyte interface（SEI）. However, the electrode presents an increased initial cou- lombic efficiency in a 1 mol/L NaPF6 electrolyte compared to that in a 1 mol/L NaCIO4 electrolyte.展开更多
基金supported by the Scholarship from China Scholarship Council(CSC)(Grant no.201604910621)。
文摘Catalyst support is extremely important for future fuel cell devices.In this work,we developed doubleshelled C/TiO2(DSCT)hollow spheres as an excellent catalyst support via a template-directed method.The combination of hollow structure,TiO2 shell and carbon layer results in excellent electron conductivity,electrocatalytic activity,and chemical stability.These uniformed DSCT hollow spheres are used as catalyst support to synthesize Pt/DSCT hollow spheres electrocatalyst.The resulting Pt/DSCT hollow spheres exhibited high catalytic performance with a current density of 462 mA mg^-1 for methanol oxidation reaction,which is 2.52 times higher than that of the commercial Pt/C.Furthermore,the increased tolerance to carbonaceous poisoning with a higher If/Ibratio and a better long-term stability in acid media suggests that the DSCT hollow sphere is a promising C/TiO2-based catalyst support for direct methanol fuel cells applications.
基金supported by the National Natural Science Foundation of China(Nos.21677159,21522706,21677167)the National Basic Research Program of China(2011CB936001)the Thousand Young Talents Program of China
文摘Great efforts have been devoted to improve the photocatalytic activity of TiO2 in the visible light region. Rational design of the external structure and adjustment of intrinsic electronic status by impurity doping are two main effective ways to achieve this purpose. A facile onepot synthetic approach was developed to prepare C-doped hollow TiO2 spheres, which simultaneously realized these advantages. The synthesized TiO2 exhibits a mesoporous hollow spherical structure composed of fine nanocrystals, leading to high specific surface area（~180 m^2/g） and versatile porous texture. Carbonate-doping was achieved by a postthermal treatment at a relatively low temperature（200°C）, which makes the absorption edge red-shifted to the visible region of the solar spectrum. Concomitantly, Ti^（3＋） induced by C-doping also functions in improving the visible-light photocatalytic activity by reducing the band gap. There exists a synergistic effect from multiple stimulatives to enhance the photocatalytic effect of the prepared TiO2 catalyst. It is not out of expectation that the asprepared C-doped hollow TiO2 spheres exhibits an improved photocatalytic activity under visible light irradiation in organic pollutant degradation.
基金the National Natural Science Foundation of China（No.21373028）.
文摘A high purity sheet-like Na2Ti307 material was synthesized by a new facile solid-state method with hollow sphere TiO2 as titanium source. X-Ray diffraction（XRD） measurement proves that no impurity phase existed when the sample was heated at 900 ℃. Charge/discharge measurement was performed in a potential range of 0.01m2.5 V at different current-rates（C-rates）. The initial charge/discharge capacities are 191/424 mA.h/g at 0.1 C and still remain as high as 101 mA.h/g after 50 cycles. CV test proves that the large irreversible capacity in the initial cycle results from the formation of the solid electrolyte interface（SEI）. However, the electrode presents an increased initial cou- lombic efficiency in a 1 mol/L NaPF6 electrolyte compared to that in a 1 mol/L NaCIO4 electrolyte.
