Integrated Ni(OH)₂‑TiO₂‑Cu₂O Hybrids with a Synergic Impact of the p–n Heterojunction/Cocatalyst for Enhanced Photocatalytic Hydrogen Production

Abstract

Designing a hybrid photocatalyst with multichannel charge separation could address the issue of rapid recombination of photo-induced electron–hole pairs from a single semiconductor and assist photocatalytic hydrogen evolution. In this work, the Ni(OH)2-TiO2-Cu2O ternary hybrid has been successfully prepared with a combination of hydrothermal-calcination-chemical reduction methods. Particularly, Ni(OH)2 species and Cu2O nanoparticles are anchored on a TiO2 nanoflake assembly. Upon light illumination, photocatalytically splitting water to hydrogen is achieved by the as-synthesized ternary hybrids. Among them, the 0.83% Ni(OH)2-TiO2–4.5% Cu2O hybrid exhibits the highest photocatalytic performance. Particularly, the hydrogen generation rate (8384.84 μmol g–1 h –1) of 0.83% Ni(OH)2-TiO2–4.5% Cu2O is 3.5 times higher than that of pristine TiO2 (2369.94 μmol g–1 h –1). It is also superior to the binary 0.83% Ni(OH)2-TiO2 and TiO2–4.5% Cu2O samples. It is demonstrated that the formed p–n junction in the interface of TiO2 and Cu2O as well as the cocatalytic effect of Ni(OH)2 species could offer multichannels for efficient charge transfer, contributing to the improved photocatalytic hydrogen production