Spherical NiCu phyllosilicate photocatalysts for hydrogen generation

To enhance the photocatalytic performance of semiconductors, a highly active and durable SiO2@xNiCuPS photocatalyst was evaluated for photocatalytic hydrogen generation. The photocatalyst was prepared by a hydrothermal method using SiO2 spheres, and a 1:1 Cu:Ni mixture (5 and 10 wt%). The reaction gave a highly stable phyllosilicate material with a core@shell structure. The materials were characterized by a range of techniques. DRS data revealed indirect optical transitions at 1.5 eV and 2.75 eV for the SiO2@5NiCuPS and SiO2@10NiCuPS materials. The new photocatalysts were successfully tested for hydrogen generation under visible irradiation to give H-2 yields of 184 and 47 mu mol g(-1). min(-1) for SiO2@5NiCuPS and SiO2@10NiCuPS, respectively. The data suggest that the enhanced activity of adding Cu to Ni to form Ni/Cu phyllosilicates is not due to NiCu alloy formation but due to changes in the support morpholohgy brought about by metal-support interactions. The catalysts were stable over 4 repeat reaction cycles. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.