Decorated NiFeOOH on high entropy perovskite oxide by interface engineering for efficient oxygen evolution and overall water splitting

High entropy perovskite oxide (HEPO) has proved to be one of the most promising candidates in the exploration of non-precious oxygen evolution reaction (OER) catalysts. Herein, we report a chemical bath deposition method for decorating NiFeOOH on lanthanide-based high entropy perovskite oxide (La-HEO) to form a rational core–shell heterostructure through direct atomic-scale contact to further enhance the OER activity of HEPO. Compared with La-HEO and NiFeOOH, the resulting La-HEO@NiFeOOH showed excellent OER performance, requiring an overpotential of 262 mV (10 mA cm−2) and a Tafel slope of 38 mV dec−1, which owes much to the accelerated charge transfer and the optimized adsorption energy of reaction intermediates caused by synergistic effects. Meanwhile, the water splitting electrolyzer demanded a current density of 10 mA cm−2 at 1.574 V for La-HEO@NiFeOOH(1:3)||Pt/C, which is lower than that of La-HEO||Pt/C. This study illustrates the effectiveness of interface engineering to boost the OER performance of HEPO, and reveals the potential of La-HEO@NiFeOOH as a promising OER electrocatalyst.