Superhydrophilic Heteroporous MoS₂/Ni₃S₂ for Highly Efficient Electrocatalytic Overall Water Splitting

Water molecular adsorption, intermediate species transformation, and product desorption are three main steps for the water splitting that are subject to the corresponding factors of surface wettability, exposed active sites, and mass transfer, respectively. Suitable catalyst with the tailored architecture should be highly regarded to optimize the consistency and systematicness of these three procedures. Herein, highly hydrophilic heteroporous MoS₂/Ni₃S₂ on nickel foam (p-MoS₂/Ni₃S₂/NF) is fabricated through a two-steps strategy including electrodeposition and solvothermal reaction. Intensive water affinity relevant with the porous structure and composition is identified by the contact angle test. Electrochemical surface area results demonstrate the upsurge of active sites for the porous structure in comparison with other samples. The fast mass diffusion feature of the p-MoS₂/Ni₃S₂/NF catalyst is further proved by the multistep chronoamperometric for HER and OER process. Attributed to the above nature superiorities, the electrochemical activity of this p-MoS₂/Ni₃S₂/NF has been greatly enhanced. The overpotentials at a geometric current density of 10 mA cm^–2 for OER and HER significantly reduce to 185 mV and 99 mV in alkaline media, respectively. The as-prepared catalyst p-MoS₂/Ni₃S₂/NF only needs the cell voltages of 1.50, 1.62, and 1.71 V at current densities of 10, 20, and 50 mA cm^–2 to drive water splitting and performs with the good stability for at least 48 h in total. This fascinating material is designed by multiscale principles that stemmed from a better insight on the structure–activity relationship, and it can also afford constructive inspirations for the forward development of various catalytic reactions