CoNi bimetallic alloy cocatalyst-modified TiO2 nanoflowers with enhanced photocatalytic hydrogen evolution

Abstract

In terms of improving photocatalytic hydrogen production performance, inexpensive and earth-rich cocatalysts have become promising alternatives to precious metals. Herein, a novel CoNi–TiO2 photocatalyst composed of TiO2 nanoflowers and CoNi alloy was prepared by hydrothermal and chemical reduction methods. Various characterizations and test results have confirmed that the further improvement of the photocatalytic performance of the CoNi–TiO2 photocatalyst is mainly due to the fact that the bimetallic CoNi alloy can accelerate charge transfer and inhibit the recombination of photo-induced carriers. The hydrogen production rate of the prepared CoNi–TiO2 is about 24 times higher than that of the pristine TiO2, and its hydrogen production rate value can reach 6580.9 μmol g−1 h−1, and showing comparable photocatalytic performance to 0.5 wt% Pt–TiO2. In addition, combined with the characterization results, a probable mechanism for enhanced photocatalytic performance was proposed. This study provides favorable enlightenment for the design of a series of highly efficient non-precious metal TiO2-based photocatalysts.