Integrated Ni(OH)<sub>2</sub>-TiO<sub>2</sub>-Cu<sub>2</sub>O Hybrids with a Synergic Impact of the p–n Heterojunction/Cocatalyst for Enhanced Photocatalytic Hydrogen Production
Chunyan Wang, Jinyan Xiong, Zhipan Wen, Gang Cheng
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 -TiO 2 -Cu 2 O ternary hybrid has been successfully prepared with a combination of hydrothermal-calcination-chemical reduction methods. Particularly, Ni(OH) 2 species and Cu 2 O nanoparticles are anchored on a TiO 2 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 -TiO 2 –4.5% Cu 2 O hybrid exhibits the highest photocatalytic performance. Particularly, the hydrogen generation rate (8384.84 μmol g –1 h –1 ) of 0.83% Ni(OH) 2 -TiO 2 –4.5% Cu 2 O is 3.5 times higher than that of pristine TiO 2 (2369.94 μmol g –1 h –1 ). It is also superior to the binary 0.83% Ni(OH) 2 -TiO 2 and TiO 2 –4.5% Cu 2 O samples. It is demonstrated that the formed p–n junction in the interface of TiO 2 and Cu 2 O 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.