Tandem Fields Facilitating Directional Carrier Migration in Van der Waals Heterojunction for Efficient Overall Piezo‐Synthesis of H2O2

Abstract

AbstractPiezo‐synthesis of H2O2 utilizing sustainable mechanical energy as well as earth‐abundant water and oxygen is a green, cost‐effective, and promising approach. However, achieving simultaneous two‐electron water oxidation reaction (2e− WOR) and two‐electron oxygen reduction reaction (2e− ORR) faces huge challenges due to insufficient synergistic active sites and slow/messy carrier transfer. Herein, a novel 2D/2D van der Waals heterojunction consisting of BiOIO3 and carbon nitride (BIO/CN) is elaborately designed for highly efficient overall H2O2 piezo‐synthesis. Theoretical/experimental results reveal that a Z‐scheme electron transfer is formed and facilitated by the tandem interfacial electric field and the bulk piezo‐polarization field. On this basis, the carriers are efficiently separated while the oxidation/reduction capacity is preserved, thus providing the strong driving force for the 2e− WOR and 2e− ORR on BIO and CN, respectively. Furthermore, the kinetic and thermodynamic processes of WOR and ORR for H2O2 synthesis improve remarkably. Therefore, BIO/CN exhibits an excellent H2O2 yield of 259.8 µM within 30 min in pure water and air atmosphere (without any sacrificial agents and aeration). This study provides a new idea on strategically controlling electron transfer toward high‐efficiency H2O2 piezo‐synthesis and expands the avenue for developing effective environmental purification materials.