Photosynthesis of methanol from CO2 and water by CuInS2 nanorod arrays

• Main Authors: Guan-Ting Pan, 潘冠廷
• Other Authors: CHUNG-KUANG YANG
• Format: Others
• Language: en_US
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/avq54x

博士 === 國立臺北科技大學 === 工程科技研究所 === 99 === Aluminum oxide (AAO) was emplpyed as the templates to fabricate highly-ordered CuInS2 semiconductor nanostructures by chemical bath deposition (CBD). The bath solutions contain various amount of zinc nitrate for the growth of Zn-doped CuInS2 photocatalysts. The influences of zinc concentrations on structural, optical, and electrical properties, hydrogen and methanol evolution rates were investigated. The X-ray diffraction (XRD) patterns demonstrate that CuInS2 is the major crystalline phase of the as-prepared samples. When the Zn molar ratio in the bath solution was above 0.4, the conductivity of the sample changed from n-type to p-type. The band gaps and carrier densities of these samples determined from transmittance spectra and electrochemical analysis are in the range of 1.5 eV, and 2.07×1015 ~ 9.45×1020 cm-3, respectively. The maximum photocurrent density of the as-prepared sample was -2.02 mA/cm2 (with the external potential set to -1.0 V) when subjected to illumination of a 300-W Xe lamp. The largest hydrogen production rate was 0.7 mL/cm2. Furthermore, its methanol production rate is found to be 0.011 M/hr, which is far better than that of the CBD film made at the same composition (0.00011M/hr). These outstanding properties make the CuInS2 nanorod arrays suitable for photocatalysts for hydrogen and methanol production.