Coherent Design of ZnO<sub>0.5</sub>S<sub>0.5</sub>/g-C<sub>3</sub>N<sub>4</sub> Nanoheterostructures: Efficient Photocatalysts for H<sub>2</sub> Generation
Nikita S. Yadav, Niteen S. Jawale, Govind Umarji, Shubhangi R. Damkale, Sunit Rane, Sudhir S. Arbuj
Abstract
The development of nanostructured heterojunction catalysts has great potential to improve the photocatalytic H 2 generation performance. In this regard, ZnO 0.5 S 0.5 /g-C 3 N 4 (ZnOS/g-CN) semiconductor nanoheterostructures based on ZnO 0.5 S 0.5 and g-C 3 N 4 were designed through a simple method by deposition of different concentrations of ZnOS ranging from 10 to 50 wt % on graphitic carbon nitride (g-CN) nanosheets at 140 °C. The formation of the ZnOS/g-CN nanoheterostructures was confirmed via powder X-ray diffraction and supported by X-ray photoelectron spectroscopy (XPS) analysis. Field-emission scanning electron microscopy (FESEM) indicated the formation of a composite-type structure having two types of morphologies. ZnOS with distorted spherical particles were evenly deposited on the surface of g-CN sheets. Field-emission transmission electron microscopy (FETEM) and high-resolution transmission electron microscopy (HRTEM) confirmed the existence of heterostructures of ZnOS and g-CN. The absorption spectra clearly showed the distinct band gaps of ZnOS and g-CN in the nanoheterostructures. The surface area of samples was measured by the Brunauer–Emmett–Teller (BET) technique, and 50 wt % ZnOS/g-CN was found to have a large surface area (36.20 m 2 g –1 ) among all of the prepared compositions. Furthermore, the premier composition indicated high photocatalytic H 2 generation around 920.4 μmol of hydrogen per 0.1 g of catalyst via water splitting under 4 h of irradiation. The effective separation of photogenerated charge carriers due to the formation of nanoheterostructures of ZnOS/g-CN led to higher H 2 generation.