CoP-Enhanced CaTiO3 Single-Electron Oxygen Reduction Piezoelectric Catalysis for H2O2 Production

Piezoelectric catalytic production of H2O2 is a novel and environmentally friendly H2O2 production method, and many piezoelectric catalysts are currently being developed. However, all of them have the disadvantages of precious metals as cocatalysts and low catalytic efficiency. Herein, CaTiO3 was successfully prepared and loaded with the nonprecious metal CoP (CoP/CaTiO3) for piezoelectric catalytic production of H2O2. The yield of H2O2 produced by 5% CoP/CaTiO3 piezoelectric catalysis reached 9657.3 μmol L–1 g–1, which was 1.64 times than that of single-component CaTiO3, and furthermore, the performance remained stable after five cycles. This study directly demonstrates the piezoelectric response of CoP/CaTiO3 by using Piezoresponse Force Microscopy. Under ultrasonic conditions, CoP/CaTiO3 undergoes polarization, resulting in the generation of electrons (e–) and holes (h+). The e– undergoes a two-step single-electron reaction with O2 to form H2O2. Because the conduction band position of CoP is lower than that of CaTiO3, this potential difference promotes the migration of e– from CaTiO3 to CoP. This migration process effectively enhances the spatial separation of e– and h+, which significantly improves the piezoelectric catalytic performance. In this work, a nontoxic and inexpensive new piezoelectric catalytic material was synthesized by a method that can produce catalysts in large quantities, and a strategy was provided to improve the piezoelectric catalytic activity, which played a key role in promoting the green industrial production of H2O2.