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

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 pre-pared by hydrothermal and chemical reduction methods. Various characterizations and test results have confirmed that the further improvement of the photocatalytic perfor-mance 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 car-riers. 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 mmol 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.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Inexpensive and earth-rich cocatalysts, such as the CoNi alloy, have shown promising potential in improving the photocatalytic hydrogen production performance. A novel CoNi-TiO2 photocatalyst was prepared by hydrothermal and chemical reduction methods, and its enhanced performance was attributed to the accelerated charge transfer and inhibited carrier recombination facilitated by the CoNi alloy. The hydrogen production rate of the CoNi-TiO2 photocatalyst was 24 times higher than that of pristine TiO2, reaching 6580.9 mmol g-1 h-1, comparable to 0.5 wt% Pt-TiO2. This study provides valuable insights for the design of efficient non-precious metal TiO2-based photocatalysts.