Hierarchical Ni3S2-CoMoS on the nickel foam as an advanced electrocatalyst for overall water splitting

This work used nickel foam (NF) as a conductive substrate to construct a self-supporting structure catalyst, which exhibited excellent bifunctional catalytic activity for both oxygen evolution reactions (OER) and hydrogen evolution reactions (HER). Through CoMo-MOF and NF sulfuration together, NF surface participates in the reaction and grows uniform needle-shaped Ni3S2 nanorods, while CoMo-MOF transforms into CoMoSx hollow polyhedral particles, which are attached to the surface of Ni3S2 rods and formed Ni3S2-CoMoSx/NF composite. It was found that there is an obvious synergistic effect between CoMoSx, Ni3S2 and NF, thus obtaining excellent catalytic activity for both OER and HER. The overpotential of Ni3S2-CoMoSx/NF catalyst at 10 mA cm−2 is only 234 and 90 mV for HER and OER. In addition, Ni3S2-CoMoSx/NF also exhibits excellent performance in the process of overall water splitting. It can reach 10 mA cm−2 at only 1.52 V and the catalytic performance remain stable for 65 h. Therefore, the self-supporting Ni3S2-CoMoSx/NF can become a highly efficient and long-term durable bifunctional electrocatalyst for overall water splitting.