Photo- and electrocatalytic conversion driven by transition metal-assisted ferroelectric heterojunction

Ferroelectric polarization switching can dynamically modulate the catalytic activity via electronic phase transitions. Herein, we systematically investigated the hydrogen evolution reaction, oxygen evolution and reduction reaction activities of heterostructures formed by stacking transition metal-doped graphene‑zinc oxide (TM@g-ZnO) and ferroelectric In₂Se₃ monolayers using density functional theory calculations. Pt@g-ZnO/In₂Se₃ exhibits superior hydrogen evolution reaction (HER) performance, while Ni@g-ZnO/$\downarrow$-In₂Se₃ and Pd@g-ZnO/$\uparrow$-In₂Se₃ are potential bifunctional catalysts for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Notably, the polarization-induced semiconductor-to-metal transition enables interconversion between photo- and electrocatalysis. Non-adiabatic molecular dynamics simulation shows that TM@g-ZnO/$\uparrow$-In₂Se₃ has a long hot-carrier lifetime in photocatalysis, and conductivity calculation indicates that TM@g-ZnO/$\downarrow$-In₂Se₃ has high electrical conductivity in electrocatalysis. Furthermore, machine learning identifies the d-electron number of TM dopants as the dominant factor governing catalytic activity. These findings not only benefit the exploration of efficient multifunctional catalysts but also provide novel photoelectrocatalytic conversion mechanisms.