Photocatalytic hydrogen production with nickel oxide intercalated K 4Nb 6O 17 under visible light irradiation

Abstract

Nickel oxide nanoclusters were intercalated to layered niobate, K 4Nb 6O 17, to improve the photocatalytic hydrogen production for water splitting under visible light irradiation. A K 4Nb 6O 17–SSR x (Ni/Nb ratio range of 0.8–5%) series of nickel oxide intercalated layered niobates was prepared by a two-step solid-state reaction and characterized by Extended X-ray Absorption Fine Structure (EXAFS), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Energy Dispersive Spectrometer (EDS), X-ray Photoelectron Spectroscopy (XPS) and Ultraviolet–visible spectroscopy (UV–vis). The photocatalytic reaction was carried out in a quartz reactor irradiated under a 500-W halogen lamp. The K 4Nb 6O 17–SSR0.2 catalyst exhibited a much higher photocatalytic activity for water splitting than unloaded K 4Nb 6O 17 catalyst and NiO y /K 4Nb 6O 17 catalyst prepared by the conventional impregnation method. The high catalytic performance was attributed to the well dispersed nickel oxide nanoclusters intercalated into the bulk structure of K 4Nb 6O 17 catalyst and the lack of NiO particles on the external particle surface.