Effects of the cation and anion co-doping in perovskite as bifunctional electrocatalyst for water splitting

Element doping is a very important way to modify perovskite oxide (ABO3) electrocatalyst. Herein, the O, B and A-site of BaCoO3-δ are doped with F, Fe and Sr elements, respectively, which are used to investigate the effect of different doping sites on water splitting performance. The results show that doping F can generate more oxygen vacancies and increase the Co valence state. On the basis of anionic doping, when Co is partially substitute by Fe, the Fe4+ formed makes the O 2P orbital close to EF, and the bandwidth is narrower, enhancing the conductivity. Subsequently, doping Sr in A-site can change the crystal structure from P63/mmc to pm-3m, and exhibit metallic properties. This work can contribute to an effective approach for the design of perovskite oxide materials for efficient electrocatalytic water splitting.