Utilizing ion leaching effects for achieving high oxygen-evolving performance on hybrid nanocomposite with self-optimized behaviors
Daqin Guan, Gihun Ryu, Zhiwei Hu, Jing Zhou, Chung‐Li Dong, Yucheng Huang, Kaifeng Zhang, Yijun Zhong, A. C. Komarek, Ming Zhu, Xinhao Wu, Chih‐Wen Pao, Chung‐Kai Chang, Hong‐Ji Lin, Chien‐Te Chen, Wei Zhou, Zongping Shao
Abstract
Abstract Ion leaching from pure-phase oxygen-evolving electrocatalysts generally exists, leading to the collapse and loss of catalyst crystalline matrix. Here, different from previous design methodologies of pure-phase perovskites, we introduce soluble BaCl 2 and SrCl 2 into perovskites through a self-assembly process aimed at simultaneously tuning dual cation/anion leaching effects and optimizing ion match in perovskites to protect the crystalline matrix. As a proof-of-concept, self-assembled hybrid Ba 0.35 Sr 0.65 Co 0.8 Fe 0.2 O 3- δ (BSCF) nanocomposite (with BaCl 2 and SrCl 2 ) exhibits the low overpotential of 260 mV at 10 mA cm -2 in 0.1 M KOH. Multiple operando spectroscopic techniques reveal that the pre-leaching of soluble compounds lowers the difference of interfacial ion concentrations and thus endows the host phase in hybrid BSCF with abundant time and space to form stable edge/face-sharing surface structures. These self-optimized crystalline structures show stable lattice oxygen active sites and short reaction pathways between Co–Co/Fe metal active sites to trigger favorable adsorption of OH − species.