Surface-Engineered Ni(OH)₂/PtNi Nanocubes as Cocatalysts for Photocatalytic Hydrogen Production

Abstract

Exposure of specific crystallographic planes as catalyst surfaces has been reported to effectively affect the performance of noble metal cocatalysts used for photocatalytic hydrogen production via water splitting. However, the performance of noble metals for hydrogen production in alkaline solutions is usually 2 orders of magnitude lower than that in acidic media because of the weak dissociative adsorption ability of noble metals to water molecules, which may greatly limit their applications in photocatalytic hydrogen production. In this research we report a Pt-based composite cocatalyst (Ni(OH)2/PtNi nanocubes), designed by separating the dissociative sites of water molecules from active sites for photocatalytic hydrogen production. Compared with PtNi nanocube-loaded CdS, Ni(OH)2/PtNi nanocube-modified CdS exhibits a much higher photocatalytic performance for hydrogen production in alkaline solutions. This study provides a method for synthesizing highly active water-splitting/reducing photocatalysts under alkaline conditions.