Enhanced hydrogen evolution activity by novel RuSe2/CdS piezo-photocatalysts with piezoelectric field

Photocatalytic hydrogen production is identified as a prospective route for solving the energy crisis and reducing environmental pollution. However, the complexation of photogenic carriers and the lack of active sites hinder the efficiency of photocatalysis. The piezoelectric effect and the corporation of cocatalyst are considered as effective strategies to facilitate the separation of the photogenic charge carriers. Ru-based compounds such as RuSe2, RuTe2, RuS2 and their derivatives are considered as potentially alternative catalysts to the platinum cocatalyst for the hydrogen evolution realution. Herein, we prepare a novel RuSe2/CdS piezo-photocatalysts in which RuSe2 cocatalyst is synthesized by microwave method to enable efficient piezo-photocatalytic hydrogen production. The experimental results show that the hydrogen production efficiency of 1.5% RuSe2/CdS is 63.857 μmol/mg/h under solar and ultrasonic conditions, which is about 7.54 times that of pure CdS (8.468 μmol/mg/h). More importantly, the hydrogen production efficiency of 1.5% RuSe2/CdS is remain stable after seven cycles of experiments. The enhanced piezo-photocatalytic activity is attributed to the interaction and the matching energy bands between RuSe2 and CdS, which facilitates photogenic electrons extend from CdS to RuSe2 cocatalyst. This work exposes a prospect for improving photocatalytic performance, and achieving efficient piezo-photocatalysis by using mechanical energy.