Ni(OH)2-modified SrTiO3 for enhanced photocatalytic hydrogen evolution reactions

Abstract

Strontium titanate (SrTiO₃) is a promising photocatalyst because of its high chemical stability and excellent photocatalytic activity. However, the requirement of near-ultraviolet (UV) irradiation for effective photocatalysis limits its practical application. In this work, we prepared a novel Ni(OH)₂-modified SrTiO₃ composite using a simple precipitation method and confirmed that the Ni(OH)₂ nanoparticles were successfully deposited on the SrTiO₃ surface rather than incorporated into the lattice. The optimal Ni(OH)₂ loading amount for high H₂ evolution was found to be 20%, giving an activation rate of up to 1.46 mmol h⁻¹ g⁻¹, which is ca. 15 times higher than that of the pure SrTiO₃. This significant enhancement of activity could be ascribed to the lower recombination of electrons and holes in the presence of Ni(OH)₂, which was confirmed by photo-luminescence spectroscopy (PL) and photo-current response property. The present finding could shed light on the design of efficient perovskite-type oxide based photocatalysts.