International Journal of Hydrogen Energy, Vol.44, No.56, 29516-29528, 2019
Effects of graphene oxide and sacrificial reagent for highly efficient hydrogen production with the costless Zn(O,S) photocatalyst
Searching for noble metal-free co-catalyst is still a strenuous part in photocatalytic hydrogen evolution reaction (HER), as most of the great catalysts contain noble metals like the expensive platinum. The present work demonstrates a feasible synthesis method of Zn(O,S)/GO nano composite with graphene oxide (GO) to serve as an inexpensive co-catalyst. Raman spectra and transmission electron microscopy (TEM) images clearly verified that GO was successfully loaded on the surface of Zn(O,S). This GO layer could effectively decrease the charge transfer resistance and promote the charge carrier separation for enhancing hydrogen production rate. By optimizing the GO content, the best hydrogen production rate of 2840 mu g h(-1) was achieved with Zn(O,S)/0.5 wt% GO catalyst under 16 W UV lamp with illumination light at a wavelength of 352 nm, which showed about two times higher for GO-free Zn(O,S). The effect of sacrificial reagent on the hydrogen production rate of Zn(O,S)/0.5 wt% GO catalyst was also evaluated. The sacrificial reagent showed the efficiency with the following trend: ethanol > methanol > isopropanol > ethylene glycol. The mechanism for enhancing hydrogen production rate is elucidated in this paper. We consider the simple synthesis method and its low cost to make Zn(O,S)/GO a great potential for practical application. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.