Tuning ORR/OER activity by designing ferroelectric FeTiO₃ heterostructures

Abstract The integration of ferroelectricity in two-dimensional materials offers a promising strategy for tuning electrocatalytic properties. In this study, we use first-principles calculations to investigate how ferroelectricity modulates catalytic activity in non-van der Waals heterostructures (HSs). Specifically, we design ilmenene (FeTiO₃ monolayer) interfaced with ferroelectric (FE) substrates, Sc₂CO₂ and In₂Te₃, to elucidate their polarization effects on the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Our density functional theory (DFT) calculations reveal that both upward (P↑) and downward (P↓) polarization states significantly influence charge redistribution at the catalytic centre, with the P↑ state facilitating superior electron donation. These polarization effects substantially optimize the ORR/OER catalytic activity, yielding relatively low theoretical OER overpotentials (η _OER) of 0.55 V for FeTiO₃/Sc₂CO₂ and 0.63 V for FeTiO₃/In₂Te₃, respectively. These findings highlight the role of FE substrates in tailoring electrocatalytic performance, providing insights for the design of polarization-driven catalysts in energy conversion applications.