Cation–anion modification and heterostructure for cooperative regulation of electron distribution in NiMoS/NiFeMn-LDH electrocatalyst to enhance water splitting

The utility of NiFe layered double hydroxides (LDH) as water splitting electrocatalysts is limited by their low conductivity and poor hydrogen evolution reaction (HER) efficiency. To overcome these issues, a NiMoS/NiFeMn-LDH catalyst was developed with a built-in electric field using an in-situ growth method. This built-in field enhances electron transfer, significantly improving conductivity. The electronic distribution was finely tuned through cation/anion modifications and heterostructure construction, optimizing intermediate desorption from active sites. Through X-ray photoelectron spectroscopy (XPS) and Electrochemical Impedance Spectroscopy (EIS) analyses, it was elucidated that the redistribution of electrons within the catalyst significantly enhances its electrical conductivity during the reaction. Furthermore, in-situ EIS confirmed efficient electron transfer at the catalyst/electrolyte interface. The catalyst exhibits remarkable activity, achieving overpotentials of 192 mV (OER) and 112 mV (HER) at 10 mA cm^-2. A NiMoS/NiFeMn-LDH-based electrolyzer operates at 1.562 V for 10 mA cm^-2. This study provides a strategic approach for modulating the redistribution of electrons within electrocatalysts, thereby promoting efficient water splitting.