Ni super(2+)-doped Zn sub(x)Cd sub(1-x)S photocatalysts from single-source precursors for efficient solar hydrogen production under visible light irradiation

• Published in: Catalysis science & technology 2012-03, Vol.2 (3), p.581-588
• Main Authors: Wang, Yabo, Wu, Jianchun, Zheng, Jianwei, Jiang, Rongrong, Xu, Rong
• Format: Article
• Language: English
• Subjects: Emission analysis; Hydrogen evolution; Inductively coupled plasma; Light irradiation; Photocatalysis; Photocatalysts; Precursors; Sulfides
• ISSN: 2044-4753; 2044-4761
• DOI: 10.1039/c2cy00310d

Ni super(2+)-doped photocatalysts Ni(y)-Zn sub(x)C d sub(1-x)S (where 0 less than or equal to x less than or equal to 0.80, 0% less than or equal to y less than or equal to 8%) were prepared by a two-step route, which consisted of a first precipitation of single-source precursors and a subsequent solvothermal treatment of the precursors in ethylenediamine. Structural, morphological and optical properties of the as-prepared samples were characterized by XRD, UV-vis DRS, FESEM, TEM, N sub(2) physisorption, ICP-AES and XPS techniques. The photocatalytic activity was evaluated for hydrogen evolution from the aqueous solution containing sodium sulfide and sodium sulfite under visible light irradiation. All Ni super(2+)-doped samples exhibit enhanced photocatalytic activity compared with the non-doped sample. Sample Ni(4%)-Zn sub(0.4)Cd sub(0.6)S gives the highest hydrogen evolution rate of 941 mu mol h super(-1) under the optimized reaction conditions without any co-catalysts, with a corresponding quantum efficiency of 22.8% at 420 nm which is much higher compared to those of previously reported Ni super(2+)-doped metal sulfide photocatalysts. It is suggested that good crystallinity, suitable band structure and the accommodation sites introduced by Ni super(2+) doping for charge carrier separation together contribute to the high activity of such photocatalysts for hydrogen evolution.