Piezocatalytic H2O2 Production from Pure Water over a TiO2/ZnO Heterojunction through a Dual-Channel Pathway

Piezocatalytic H 2 O 2 generation has emerged as a promising alternative for sustainable H 2 O 2 synthesis, yet its development is hindered by unsatisfactory energy conversion efficiency. Herein, a TiO 2 /ZnO piezocatalyst was developed by dispersing ZnO nanorods within a TiO 2 nanosheet substrate, enabling efficient H 2 O 2 generation in pure water. By constructing a heterostructure, we developed an effective strategy to enhance charge carrier separation and migration through a built-in electric-field-induced piezoelectric effect, thereby demonstrating the superior piezocatalytic performance of the TiO 2 /ZnO composite. Compared to pure TiO 2 and ZnO, the TiO 2 /ZnO heterojunction exhibited significantly enhanced piezocatalytic H 2 O 2 production, achieving a yield of 2078.14 μmol·g –1 ·h –1 in pure water, surpassing most reported piezocatalysts. Reactive species analysis revealed a dual-channel H 2 O 2 generation mechanism, featuring an oxygen reduction reaction (ORR)-dominated pathway with a minor contribution from the water oxidation reaction (WOR). Furthermore, TiO 2 /ZnO exhibits excellent piezocatalytic performance in degrading various pollutants. This work provides valuable insights into piezocatalytic H 2 O 2 generation and offers a potential pathway for the green and sustainable synthesis of H 2 O 2 .