Conductive origin and design principles of electrically controllable high conductivity La-doped perovskites

Abstract

Emerging pulse electric current-induced nanoparticle exsolution (PECINE) is an efficient method for enhancing the electrocatalytic performance of perovskite materials. It has great potential in the field of surface engineering due to its simplicity and ability to rapidly induce nanoparticle (NP) exsolution. However, the conductivity of perovskite materials is crucial in the PECINE process, and there is a lack of theories that enable rational design of doped perovskite structures with high conductivity. To address this issue, we performed first-principles calculations based on density-functional theory (DFT) to optimize the conductivity of the La-doped (La_xSr_1−x)_0.8Ti_0.94Ni_0.06O₃ (LSTN) structural model. Subsequently, we experimentally validated this optimized conductivity model through PECINE. Our findings establish a novel design principle for optimizing the conductivity of perovskite structures. This design principle has the predictive ability to screen out doped perovskite materials with a higher conductivity than the undoped structure by a factor of 5.18. Consequently, this promotes more NP exsolution on the perovskite surface during the PECINE process and enhances the perovskite materials' oxygen evolution reaction (OER) activity.