Noble Metal-Free Reduced Graphene Oxide-ZnxCd1鈥?i>xS Nanocomposite with Enhanced Solar Photocatalytic H2-Production Performance

详细信息    查看全文

• 作者：Jun Zhang ; Jiaguo Yu ; Mietek Jaroniec ; Jian Ru Gong
• 刊名：Nano Letters
• 出版年：2012
• 出版时间：September 12, 2012
• 年：2012
• 卷：12
• 期：9
• 页码：4584-4589
• 全文大小：310K
• 年卷期：v.12,no.9(September 12, 2012)
• ISSN：1530-6992

文摘

Design and preparation of efficient artificial photosynthetic systems for harvesting solar energy by production of hydrogen from water splitting is of great importance from both theoretical and practical viewpoints. ZnS-based solid solutions have been fully proved to be an efficient visible-light driven photocatalysts, however, the H₂-production rate observed for these solid solutions is far from exciting and sometimes an expensive Pt cocatalyst is still needed in order to achieve higher quantum efficiency. Here, for the first time we report the high solar photocatalytic H₂-production activity over the noble metal-free reduced graphene oxide (RGO)-Zn_xCd_1鈥?i>xS nanocomposite prepared by a facile coprecipitation-hydrothermal reduction strategy. The optimized RGO-Zn_0.8Cd_0.2S photocatalyst has a high H₂-production rate of 1824 渭mol h^鈥? g^鈥? at the RGO content of 0.25 wt % and the apparent quantum efficiency of 23.4% at 420 nm (the energy conversion efficiency is ca. 0.36% at simulated one-sun (AM 1.5G) illumination). The results exhibit significantly improved photocatalytic hydrogen production by 450% compared with that of the pristine Zn_0.8Cd_0.2S, and are better than that of the optimized Pt-Zn_0.8Cd_0.2S under the same reaction conditions, showing that the RGO-Zn_0.8Cd_0.2S nanocomposite represents one of the most highly active metal sulfide photocatalyts in the absence of noble metal cocatalysts. This work creates a green and simple way for using RGO as a support to enhance the photocatalytic H₂-production activity of Zn_xCd_1鈥?i>xS, and also demonstrates that RGO is a promising substitute for noble metals in photocatalytic H₂-production.

Keywords:

Graphene; Zn_xCd_1鈭?i>xS solid solution; solar-light-driven; photocatalytic hydrogen production