Interfacing CdS particles on Ni foam as a three-dimensional monolithic photocatalyst for efficient visible-light-driven H_2 evolution

摘要

Solar photocatalytic water splitting using particulate semiconductors has been valued as a potentially scalable way for the production of clean H-2 energy, yet the performances of the powder-suspension systems are constrained by insufficient utilization of light energy and tedious recycling of photocatalyst particles. Here, we present a high-performance photocatalytic H-2 evolution using a visible-light-driven CdS-based monolithic photocatalyst with three-dimensional (3D) heterostructure. The monolithic photocatalyst is fabricated by firmly growing CdS microspheres on a Ni(OH)(2) nanosheet-modified Ni foam (NF) (denoted as CdS-NiSx/NF) via a simple hydrothermal process. The structure and component synergy endows the monolithic CdS-NiSx/NF photocatalyst advantageous features including high-density CdS microspheres for visible light harvesting, multiple heterojunction interfaces for efficient electron-hole separation, and abundant interfacial NiSx active sites for efficient H-2 evolution reaction (HER). Upon visible light irradiation, the monolithic CdS-NiSx/NF photocatalyst exhibits an outstanding photocatalytic H-2 evolution activity with an enhanced rate of 6.2 mmol.h(-1)g(cds)(-1), which is 6 times higher than that of the suspended CdS powder. In addition, the structural integrity of the CdS-NiSx/NF enables a good stability for H-2 evolution over a 30 h reaction. This monolithic photocatalyst is scalable in preparation and compatible for device fabrication, which offers great potentials for applications in solar cells, photoelectrocatalysis, and electrocatalysis. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.