Enhanced OER Performance through Electronic Structure Engineering in Artificial LaNiO3/SrRuO3 Superlattices

The engineering of the electronic structure in transition metal oxide (TMO) catalysts has emerged as a promising approach to enhance the oxygen evolution reaction (OER) in water-splitting, achieved through precise modulation of the absorption and desorption energies of water intermediates. Among various strategies, strain-induced tunability in electronic structures has shown great potential to significantly improve the performance of the OER performance. In this study, we utilized artificial superlattices (LaNiO3)n/(SrRuO3)m (LNOn/SROm) to optimize the surface orbital occupancy of LNO and maximize the strain effect's effectiveness. Our findings indicate that, compared to single-layer LNO films, the LNO1/SRO2 superlattice exhibits an impressive 28% reduction in Tafel slope, along with an approximately 315% enhancement in catalytic current density at 1.65 V for the OER process. The approach of the 3dx2‐y2 orbital of eg toward the 2p orbital by strain in superlattice is responsible for this OER enhancement, where the centering of eg and 2p orbitals is improved. Our results not only provide a promising strategy for the enhanced OER by engineering the TMO's surface electronic structure, but also showcase the exceptional design of OER catalysts using artificial TMO superlattices.