Aurivillius-layered Bi2WO6 nanoplates with CoOx cocatalyst as high-performance piezocatalyst for hydrogen evolution

Abstract

Developing a high-performance piezocatalyst that directly transforms mechanical energy into hydrogen is highly desirable in the field of new energy. Herein, the Aurivillius-layered Bi₂WO₆ (BWO) nanoplates are prepared through a hydrothermal reaction at a moderate temperature of 160 °C, and exhibit strong piezoelectric properties, enabling them to catalyze water splitting through ultrasonic-induced piezocatalysis effect. The hydrogen evolution reaction (HER) and H₂O₂ generation efficiencies are measured to be 0.43 and 0.36 mmol g⁻¹ h⁻¹, respectively. To further boost piezocatalytic performance, cobalt oxide nanoparticles are intentionally photo-deposited onto these nanoplates as cocatalyst. This configuration results in a significantly boosted HER performance with an efficiency of 3.59 mmol g⁻¹ h⁻¹, which is 2.8 times higher than that of pristine nanoplates and demonstrates strong competitiveness compared to other reported piezocatalysts. The cobalt oxide cocatalyst plays a crucial role in facilitating efficient charge separation and migration, increasing the charge concentration, and ultimately enhancing piezocatalytic HER activity. Overall, this work highlights the potential of Aurivillius-layered bismuth oxide compounds as efficient piezocatalysts and provides valuable insights for designing high-performance piezocatalysts in the field of new energy.