Enhanced Piezocatalytic Water Splitting by Platinum-Decorated Barium Titanate

Abstract

Piezocatalysis has emerged as a promising field of research that uses mechanical energy to drive a chemical change. There is growing evidence that piezocatalysts can perform challenging chemical conversions from organic transformations to water splitting. A key challenge to piezocatlaysis is mitigating the inherent high relative permittivity of a ferroelectric material. This high permittivity restricts the transfer of carriers required for a chemical reaction to occur and reduces the reaction rate. Here the concept of producing a co-catalyst system is taken to enhance carrier mobility increasing the observed reaction rate. The study highlights the importance of determining the sonochemical and piezocatalytic contributions to catalysis. The combination of a Pt metal co-catalyst with BaTiO₃ through a simple solid-state method led to a four fold increase in the rate of H₂ production compared to BaTiO₃ and sonochemical reactions in the absence of a catalyst. BaTiO₃/Pt is found to exhibit stable piezocatalytic performance over 12 h. Where there is a deviation from steady-state water splitting, it is shown that this is due to mechanical removal of Pt rather than a phase change in the catalyst system. This work confirms the additive benefits of hybrid materials for improving piezocatalytic processes.