“…Therefore, the development of bifunctional alternatives with low cost, high activity, and long stability is urgently needed. In the past decade, extensive efforts have been dedicated to exploiting diverse lowcost, reliable, and high-efficient electrocatalysts for overall water splitting, including transition metal phosphides [8,9], chalcogenides [10,11], hydroxides [12,13], oxides [14,15], etc. Among various materials, perovskite oxide with the general formula of ABO 3 , where A represents a rare-earth or alkaline earth element and B indicates a transition metal ion, has emerged as a promising alternative to precious metal-based catalysts due to their compositional flexibility, antioxidative features, and structural tunability [16,17].…”