半導體光觸媒還原二氧化碳轉甲醇之研究

本研究採用化學水浴沉積法( Chemical Bath Deposition, CBD )於銦錫導電玻璃與陽極氧化模鋁板上成長單晶銅銦二硫膜。此研究在酸性溶液中以化學水浴沉積法於陽極氧化鋁膜(AAO)孔洞內製備出高度有序之銅銦二硫奈米管電極，其化學水浴沉積法溶液包括：氯化銅、氯化銦、硝酸鋅、硫代乙醯銨與硝酸銨，且探討將不同比例之硝酸銦濃度對於單晶銅銦二硫之結構、光學、電性、產氫與產甲醇之影響。在X-光粉末繞射儀分析中，本研究所製備薄膜之晶相為單晶銅銦二硫晶型。此外，藉由外加電壓與通過電流密度之關係，可得摻雜不同硝酸鋅至銅銦二硫之平帶電位，其隨著水溶液中鋅之莫爾比率高於0.4，本研究所製備薄膜之半導體性質將由n型轉變為p型。此外，由穿透光譜與光電性質量測可得薄膜之膜厚、能隙值與載子濃度各別為1.5 eV與2.07×1015 ~ 9.45×1020 cm-3。電性量測方面，其薄膜在偏壓-1.0伏與300瓦氙燈照射下，其光電流為-2.02 mA/cm2。在氫氣與甲醇之產量評估中，薄膜最高產量分別為0.7 mL/cm2 與 0.011 M/hr。由實驗可得知其可見光性質可運用於太陽能電池與光觸媒上，有利於產氫與還原二氧化碳形成甲醇。

關鍵字

光電化學；光觸媒；光吸收層； CuInS2晶相

並列摘要

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.

並列關鍵字

photoelectrochemical performance ； photocatalysts ； photo-absorbing layer ； CuInS2 crystalline

參考文獻

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[3] T. Ishii, H. Kato, A. Kudo, “H2 evolution from an aqueous methanol solution on SrTiO3 photocatalysts codoped with chromium and tantalum ions under visible light irradiation,” J. Photoch. Photobio. A. 163 (2004) 181-186.

[4] J.K. Koh, J.A. Seo, J.H. Koh, J.H. Kim, J.A. Navío, “Templated synthesis of Ag loaded TiO2 nanostructures using amphiphilic polyelectrolyte,” Mater. Lett. 63 (2009) 1360-1362.

[5] C. Colón, M. Maicu, M.C. Hidalgo, “Cu-doped TiO2 systems with improved photocatalytic activity,” Appl. Catal. B 67 (2006) 41-51.

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半導體光觸媒還原二氧化碳轉甲醇之研究

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