Herein, we describe a strategy for fabricating ordered mesoporous In2O3-reduced graphene oxide(r GO)nanocomposite through ultrasonic mixing, where ordered mesoporous In2O3 nanoparticles are synthesized via the nanocas...Herein, we describe a strategy for fabricating ordered mesoporous In2O3-reduced graphene oxide(r GO)nanocomposite through ultrasonic mixing, where ordered mesoporous In2O3 nanoparticles are synthesized via the nanocasting route by using mesoporous silica as a hard template, which possess ordered mesostructure with a large surface area of 81 m2g-1, and r GO nanosheets are synthesized from graphite via graphene oxide(GO) as intermediate. After coupled with r GO, mesoporous In2O3 could maintain its ordered mesostructure. We subsequently investigate the gas-sensing properties of all the In2O3 specimens with or without r GO for different gases. The results exhibit the ordered mesoporous In2O3-r GO nanocomposite possesses significantly enhanced response to ethanol even at low concentration levels, superior over pure mesoporous In2O3 nanoparticles. Similar strategy could be extended to other ordered mesoporous metal oxide–r GO nanocomposite for improving the gas-sensing property.展开更多
Small Ag clusters confined in the channels of ordered mesoporous anatase TiO2 have been fabricated via a vacuum-assisted wet-impregnation method, utilizing well-ordered mesoporous anatase TiO2 with high thermal stabil...Small Ag clusters confined in the channels of ordered mesoporous anatase TiO2 have been fabricated via a vacuum-assisted wet-impregnation method, utilizing well-ordered mesoporous anatase TiO2 with high thermal stability as the host. The composites have been characterized in detail by X-ray diffraction, X-ray photoelectron spectroscopy X-ray absorption fine structure （XAFS） spectroscopy, N2 adsorption, UV-visible diffuse reflectance spectroscopy and transmission electron microscopy. The results indicate that small Ag clusters are formed and uniformly confined in the channels of mesoporous TiO2 with an obvious confinement effect. The presence of strong AgO interactions involving the Ag clusters in intimate contact with the pore walls of mesoporous TiO2 is confirmed by XAFS analysis, and favors the separation of photogenerated electron-hole pairs, as shown by steady-state surface photovoltage spectroscopy and transient-state surface photovoltage measurements. The ordered mesoporous Ag/TiO2 composites exhibit excellent solar-light-driven photocatalytic performance for the degradation of phenol. This is attributed to the synergistic effects between the small Ag clusters acting as traps to effectively capture the photogenerated electrons, and the surface plasmon resonance of the Ag clusters promoting the absorption of visible light. This study clearly demonstrates the high-efficiency utilization of noble metals in the fabrication of high-performance solar-light-driven photocatalysts.展开更多
基金supported by the National Natural Science Foundation of China(21006116,51362024)the Natural Science Foundation of Ningxia(NZ12111,NZ14010)the Prophase Research Special Project of the National Basic Research Program of China(2012CB723106)
文摘Herein, we describe a strategy for fabricating ordered mesoporous In2O3-reduced graphene oxide(r GO)nanocomposite through ultrasonic mixing, where ordered mesoporous In2O3 nanoparticles are synthesized via the nanocasting route by using mesoporous silica as a hard template, which possess ordered mesostructure with a large surface area of 81 m2g-1, and r GO nanosheets are synthesized from graphite via graphene oxide(GO) as intermediate. After coupled with r GO, mesoporous In2O3 could maintain its ordered mesostructure. We subsequently investigate the gas-sensing properties of all the In2O3 specimens with or without r GO for different gases. The results exhibit the ordered mesoporous In2O3-r GO nanocomposite possesses significantly enhanced response to ethanol even at low concentration levels, superior over pure mesoporous In2O3 nanoparticles. Similar strategy could be extended to other ordered mesoporous metal oxide–r GO nanocomposite for improving the gas-sensing property.
文摘Small Ag clusters confined in the channels of ordered mesoporous anatase TiO2 have been fabricated via a vacuum-assisted wet-impregnation method, utilizing well-ordered mesoporous anatase TiO2 with high thermal stability as the host. The composites have been characterized in detail by X-ray diffraction, X-ray photoelectron spectroscopy X-ray absorption fine structure （XAFS） spectroscopy, N2 adsorption, UV-visible diffuse reflectance spectroscopy and transmission electron microscopy. The results indicate that small Ag clusters are formed and uniformly confined in the channels of mesoporous TiO2 with an obvious confinement effect. The presence of strong AgO interactions involving the Ag clusters in intimate contact with the pore walls of mesoporous TiO2 is confirmed by XAFS analysis, and favors the separation of photogenerated electron-hole pairs, as shown by steady-state surface photovoltage spectroscopy and transient-state surface photovoltage measurements. The ordered mesoporous Ag/TiO2 composites exhibit excellent solar-light-driven photocatalytic performance for the degradation of phenol. This is attributed to the synergistic effects between the small Ag clusters acting as traps to effectively capture the photogenerated electrons, and the surface plasmon resonance of the Ag clusters promoting the absorption of visible light. This study clearly demonstrates the high-efficiency utilization of noble metals in the fabrication of high-performance solar-light-driven photocatalysts.
