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
To promote the photocatalytic performance TiO2 and enlarge its application in visible region, carbon doped TiO2 (C/TiO2) composites were synthesized by wet impregnation method using sucrose as a precursor and used for...To promote the photocatalytic performance TiO2 and enlarge its application in visible region, carbon doped TiO2 (C/TiO2) composites were synthesized by wet impregnation method using sucrose as a precursor and used for phenol photocatalytic reaction. The synthesized products were characterized by Nitrogen adsorption-desorption isotherms (BET), X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-visible diffuse reflectance spectroscopy (UV-vis) techniques. The results showed that the obtained TiO2 was anatase phase in the C/TiO2 products, and its crystallite size was 11.7 nm, respectively. Carbon amount and calcined temperature of C/TiO2 can promote phenol removal. In this experiment, 5% carbon and 500 ℃ are the best choice for photocatalyst preparation. Under the UV light irradiation, 5%C/TiO2 (500 ℃, 2 h) exhibited the efficiency of 70.0% for phenol degradation within 150 min whereas TiO2 (500 ℃, 2 h) had 53.0% in the same duration of time. Also 5%C/TiO2 (500 ℃, 2 h) has higher photocatalytic performance under sunlight than pure TiO2. A combination of factors that include the smallest crystalline size, higher anatase percent, less band gap energy value and more oxygen vacant resulted in higher photocatalytic activities of 5%C/TiO2 (500 ℃, 2 h).展开更多
Sunlight-driven C-TiO2/FeTiO3 composites were synthesized with different weight fractions of FeTiO3. The as-prepared samples were characterized by UV-Visible diffuse reflectance spectroscopy, Fourier transform infrare...Sunlight-driven C-TiO2/FeTiO3 composites were synthesized with different weight fractions of FeTiO3. The as-prepared samples were characterized by UV-Visible diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction analysis, transmission electron microscopy, scanning electron microscopy, energy-dis- persive X-ray spectroscopy, and photoluminescence. Under sunlight irradiation, the C-TiO2/FeTiO3 photocatalysts degraded methyl orange (MO) efficiently and displayed much higher photocatalytic activity than that of pure FeTiO3 or carbon-doped titanium dioxide (C-TiO2), and the C-TiOE/FeTiO3 photocatalyst with 10 wt% of FeTiO3 exhibited the highest photocatalytic activity. The enhancement of photocatalytic activity was mainly ascribed to the formation of a heterojunction between C-TiO2 and FeTiO3, which facilitated the transfer and separation of photogenerated electron-hole pairs. The quenching effects of different scavengers demonstrated that the reactive superoxide radicals (02-) and hydroxyl radicals (OH) played a major role in the MO degradation. The possible photocatalytic mechanism is discussed on the basis of the band structures of C-TiO2 and FeTiO3. To further enhance the photocatalytic efficiency, double-heterojunctioned CQD/C-TiO2/FeTiO3 composite was prepared by loading carbon quantum dots onto the C-TiO2/FeTiO3 surface.展开更多
基金supported by the Scholarship from China Scholarship Council(CSC)(Grant no.201604910621)。
摘要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Funded by Yunnan Provincial Agricultural Joint Project (No.2018FG001-051)Yunnan Provincial Department of Education Research Fund (No. 2020Y0414)
摘要To promote the photocatalytic performance TiO2 and enlarge its application in visible region, carbon doped TiO2 (C/TiO2) composites were synthesized by wet impregnation method using sucrose as a precursor and used for phenol photocatalytic reaction. The synthesized products were characterized by Nitrogen adsorption-desorption isotherms (BET), X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-visible diffuse reflectance spectroscopy (UV-vis) techniques. The results showed that the obtained TiO2 was anatase phase in the C/TiO2 products, and its crystallite size was 11.7 nm, respectively. Carbon amount and calcined temperature of C/TiO2 can promote phenol removal. In this experiment, 5% carbon and 500 ℃ are the best choice for photocatalyst preparation. Under the UV light irradiation, 5%C/TiO2 (500 ℃, 2 h) exhibited the efficiency of 70.0% for phenol degradation within 150 min whereas TiO2 (500 ℃, 2 h) had 53.0% in the same duration of time. Also 5%C/TiO2 (500 ℃, 2 h) has higher photocatalytic performance under sunlight than pure TiO2. A combination of factors that include the smallest crystalline size, higher anatase percent, less band gap energy value and more oxygen vacant resulted in higher photocatalytic activities of 5%C/TiO2 (500 ℃, 2 h).
基金the University Grants Commission(UGC), New Delhi,India,for financial support with Ref.No.:17-06/ 2012(i)EU-V
摘要Sunlight-driven C-TiO2/FeTiO3 composites were synthesized with different weight fractions of FeTiO3. The as-prepared samples were characterized by UV-Visible diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction analysis, transmission electron microscopy, scanning electron microscopy, energy-dis- persive X-ray spectroscopy, and photoluminescence. Under sunlight irradiation, the C-TiO2/FeTiO3 photocatalysts degraded methyl orange (MO) efficiently and displayed much higher photocatalytic activity than that of pure FeTiO3 or carbon-doped titanium dioxide (C-TiO2), and the C-TiOE/FeTiO3 photocatalyst with 10 wt% of FeTiO3 exhibited the highest photocatalytic activity. The enhancement of photocatalytic activity was mainly ascribed to the formation of a heterojunction between C-TiO2 and FeTiO3, which facilitated the transfer and separation of photogenerated electron-hole pairs. The quenching effects of different scavengers demonstrated that the reactive superoxide radicals (02-) and hydroxyl radicals (OH) played a major role in the MO degradation. The possible photocatalytic mechanism is discussed on the basis of the band structures of C-TiO2 and FeTiO3. To further enhance the photocatalytic efficiency, double-heterojunctioned CQD/C-TiO2/FeTiO3 composite was prepared by loading carbon quantum dots onto the C-TiO2/FeTiO3 surface.