The construction of defective FeCo-LDHs by in-situ polyaniline curved strategy as a desirable bifunctional electrocatalyst for OER and HER

Abstract Here, Fe, Co-layered double hydroxide and polyaniline composites onto nickel foam (NF) (FeCo-LDH/PANI) were fabricated via one-step co-electrodeposition method. The test results indicate the co-existence of the amorphous structure and the smaller size of crystal district with more defects in optimal FeCo-LDH/PANI. Importantly, it is found that there are more defects in FeCo-LDH/PANI compared to that of FeCo-LDH possibly attributed to the local etching of H+ released from the polymerization of aniline. Benefitting from the numerous defects, higher electrochemical surface area (ECSA), lower charge-transfer resistance and electron interaction, the optimized FeCo-LDH/PANI needs the overpotentials of 104, 246, 285 and 323 mV vs RHE for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) to achieve 10 and 100 mA cm−2, and shows desirable stability. Noticeably, the optimal FeCo-LDH/PANI requires a cell voltage of 1.53 V to drive 10 mA cm−2 for the whole water splitting.