Photoanode Assisted Visible-light-driven Selective Oxidation of Alcohol

• Main Authors: Wei-Ru Guo, 郭瑋汝
• Other Authors: Tai-Chou Lee
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/5d85jw

碩士 === 國立中央大學 === 化學工程與材料工程學系 === 106 === The process of photocatalytically selective oxidation of biomass, which is eco-friendly and energy saving, harvests abundant sunlight to produce high value-added chemicals. We aim to develop a photoanode using BiVO4 as target material to absorb visible light in application of selective oxidation of alcohols. This study first focus on improving BiVO4 photoanode, and discuss three methods for improving photocurrent densities and stability. First, we attempt to fabricate Bi2O3/BiVO4 p-n junction through an alkaline thermal treatment. Although Bi2O3 phase wasn’t observed , the photocurrent densities still raised by 29% at 1.23 V vs. RHE compared with that of pristine BiVO4. Second, the enhancement of photocurrent densities in the low bias region was attained during loading MnOx cocatalyst on BiVO4 photoanode surface, but the photocurrent densities in the high bias region was suppressed. This result indicated that loading cocatalyst can promote the reaction kinetics, but charge recombination might happen between the interfaces. Last, coating crystalline TiO2 as a protection layer enhanced the photocurrent density by 15% at 1.23 V vs. RHE. And TiO2/BiVO4 photoanode dominated stability than aforementioned photoanodes. In addition, we calculated IPCE of BiVO4 photoanode with or without sacrificial reagent in electrolyte which is capable of measurement of absorption efficiency (ηabs), electron-hole separation efficiency (ηbulk) and semiconductor/electrolyte interface charge transfer efficiency (ηsurf) of BiVO4 photoanode, respectively.