Enhanced oxygen evolution reaction by stacking single-crystalline freestanding SrRuO3

Single-crystalline transition metal oxide thin film has been employed to perceive the fundamental functions of electronic structure and charge transfer processes in water splitting processes. However, surface area enlargement strain tunability a single-crystalline are restricted conventional epitaxy. In this study, we report oxygen evolution reaction (OER) enhancement by stack multilayer SrRuO 3 featured single-crystallinity, flexibility, stackability. The controllable multiple cylindrical for magnitude order emergent transition, from t 2g (3↑, 1↓) (3↑) e g (1↑), Ru efficiently enhances OER performance, overpotential can be reduced ~74 % ~78 KOH HClO 4 respectively at 5 mA/cm 2 . Our study provides an approach fine manipulation freestanding morphologically, efficient strategy aiming extreme electrochemically active engineering strain. We (SRO) with stackability, which was achieved rigid heterostructure via water-dissolution Sr Al O 6 sacrifice interlayers. Benefiting combination electrochemical high-spin state, our SROs exhibit dramatic improvement activity. • Freestanding is fabricated. high/low-spin state occurs engineered Stacking offers tremendous area. These approaches improve performance reaction.