Cu2-xS Decorated on SnS2 Nanocomposite: Boosting up Photocatalytic CO2 Reduction by Surfactant Modification

• Main Authors: Yi-Hsin Cheng, 鄭怡馨
• Other Authors: Jinn-Hsuan Ho
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/2mqsnf

碩士 === 國立臺灣科技大學 === 化學工程系 === 107 === This study uses an artificial photosynthesis system to reduce carbon dioxide to hydrocarbons as an alternative energy source with an aim to improve the environmental and energy issues. In this study, the solvothermal method using Sn, Cu, S with different mixed surfactants was used to synthesize tin disulfide and copper sulfide. The energy band gap and position of the two materials are suitable for carbon dioxide reduction reaction, and the two semiconductor materials can be mixed as hetero-junctions. It can effectively separate electrons and holes after excitation, reduce the phenomenon of electron-hole radiation recombination, and make more excitons drift to the surface of the material for carbon dioxide reduction reaction. We use the surfactant and prove that it can increase the dispersibility of particles, enhance crystallinity, and improve the quantum efficiency of carbon dioxide reduction reaction. In this study, first we analyze the characteristics of crystal structure, composition, and optical properties, and then perform gas chromatography studio. We found that the hetero-structure of tin disulfide and copper sulfide can produce acetaldehyde and small amounts of ethanol and methanol. With the photochemical quantum conversion efficiency up to about 0.061%. The reaction quantum efficiency was optimized by controlling the mixing ratio of tin disulfide, copper disulfide and changing the surfactant. By mixing the surfactant with its hetero-structure, a higher yield of acetaldehyde product can be obtained effectively. Compared with different ratios, photochemical quantum conversion efficiency can be increased to 0.313% with tin sulfide and copper sulfide mixed in a ratio of 1:1:2 with the cationic surfactant CTAB. From this study, it is proved that p-n hetero-junction structure with surfactant can increase the uniformity and dispersion of tin disulfide and copper sulfide, enhance crystallinity, and improve the photocatalyst carbon dioxide reduction reaction effectively.