Graphene Oxide Based Photocatalyst for CO2 Reduction

• Main Authors: Hsin-Cheng Hsu, 許新城
• Other Authors: Chen-Hao Wang
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/79201113028210992482

博士 === 國立臺灣科技大學 === 材料科學與工程系 === 102 === Artificial photosynthesis is one of the solutions to solve global warming and mitigate the rising demands of energy consumption. Photocatalytic conversion of carbon dioxide (CO2) to hydrocarbons such as methanol makes possible simultaneous solar energy harvesting and CO2 reduction, resulting in solution for both the energy demands and environmental problems. This work describes a promising photocatalyst based on improved graphene oxides (iGOs), which have high photocatalytic conversion efficiency of CO2 to hydrocarbon fuels. Improved Hummer’s method has been applied to synthesize the GO based photocatalyst for the enhanced catalytic activity. The photocatalytic CO2 to methanol conversion rate on the pristine improved graphene oxide is 0.172 μmole g-1-cat. h-1 under visible light, which is four-fold higher than the pure TiO2 (P25). On the other hand, we have also synthesized a composite catalyst based on molybdenum disulfide-iGO system.The MoS2 nanosheet decorated improved graphene oxide (iGO) hybrid nanostructures are fabricated by a facial one-step hydrazine-assisted hydrothermal method. The photophysical properties of the synthesized photocatalysts have been investigated by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), UV-Vis spectrometer, Ultraviolet photoelectron spectroscopy (UPS), cyclic voltammetry (CV), linear sweep voltammetry (LSV) and X-ray photoelectron spectroscopy (XPS). Enhanced visible light-driven activity for the CO2 photoreduction to solar fuel has been achieved. The average apparent CO2 reduction to solar fuel formation rate of MoS2 nanosheet decorated iGO composite is more than 10 times higher than the pristine iGO; or 40 times that of TiO2 (P25). The MoS2 nanosheet decorated iGO composite nanostructures makes an outstanding contribution to the excellent photocatalytic CO2 reduction.