Highly Efficient and Stable Cadmium Chalcogenide Quantum Dot/ZnO Nanowires for Photoelectrochemical Hydrogen Generation

详细信息    查看全文

• 作者：Minsu Seol ; Ji-Wook Jang ; Seungho Cho ; Jae Sung Lee ; Kijung Yong
• 刊名：Chemistry of Materials
• 出版年：2013
• 出版时间：January 22, 2013
• 年：2013
• 卷：25
• 期：2
• 页码：184-189
• 全文大小：426K
• 年卷期：v.25,no.2(January 22, 2013)
• ISSN：1520-5002

文摘

Although cadmium chalcogenide quantum dot-sensitized photoanode can utilize the whole visible region of the solar spectrum, its poor photochemical stability owing to hole-induced anodic corrosion remains a major problem for the application in photoelectrochemical hydrogen generation systems. Here, modification with IrO_x路nH₂O, a well-known water-oxidation catalyst substantially improves the photochemical stability of the quantum dot-sensitized photoanode. Moreover, it induces an increased photocurrent and a cathodic shift of the onset potential. This is the first example that an oxygen-evolution catalyst is employed on a quantum dot-sensitized electrode system, and it shows 13.9 mA cm^鈥? (at 0.6 V) and 鈭?.277 V vs the reversible hydrogen electrode (RHE), which are the highest photocurrent density and the lowest onset potential attained with a ZnO-based electrode, respectively. An average hydrogen evolution rate of 240 渭mol h^鈥? cm^鈥? at 0.6 V vs RHE has been achieved on a IrO_x路nH₂O modified electrode, with almost 100% of faradaic efficiency.

Keywords:

photoelectrochemical cell; hydrogen generation; ZnO nanowire; cadmium chalcogenide