Abstract
Transition metal oxide thin film has recently become an attractive platform for enhanced catalytic activity and to perceive the fundamental functions of d electron structure and charge transfer processes. Owing to the long-range lattice ordering and accurate stoichiometry, the single-crystalline transition metal oxide thin film enables the mechanism discussion of electrochemistry down to the atomic level. However, it is technically unviable in the fabrication of transition metal oxide thin film with a substantial surface area and strain condition. Here we report the oxygen evolution reaction enhancement by a stack of multilayer SrRuO3 featured with single-crystallinity, flexibility, and stackability, which was achieved from the rigid heterostructure via a water-dissolution of Sr3Al2O6 sacrifice interlayers. The controllable stack of multilayer SrRuO3 and the emergent high-spin state t2g(3↑)eg(1↑) of Ru efficiently enhances the oxygen evolution reaction activity. Our study provides an approach for fine manipulation of single-crystalline freestanding transition metal oxide morphologically, and an efficient strategy aiming at the extreme enhancement of the electrochemically active surface area and strain condition.
Transition-metal-oxide based functional thin-film device using leakage-free electrolyte