Facile construction Co-doped and CeO2 heterostructure modified NiS2 grown on foamed nickel for high-performance bifunctional water electrolysis catalysts

The development of cost-effective non-precious metal bifunctional electrocatalysts with performance comparable to that of precious metal-based catalysts is an important factor in achieving industrial hydrogen production from electrolytic water. In order to prepare electrocatalysts with highly exposed active sites and high intrinsic activity, unique heterostructure and element doped 2D Co–NiS2/CeO2 nanosheets grown on foamed nickel (Co–NiS2/CeO2/NF) are prepared by hydrothermal reaction and annealing. The Co–NiS2/CeO2/NF catalyst demonstrates excellent performance and stability in alkaline solutions. In 1.0 M KOH solution, the overpotentials for the HER and OER were found to be as low as 88 mV and 240 mV, respectively. Moreover, when utilized as both the anode and cathode in a standard two-electrode water electrolyzer, Co–NiS2/CeO2/NF delivers 50 mA cm−2 at a relatively low voltage of 1.82 V and was able to maintain its high performance levels without any degradation even after 48 h of CP test. The combination of doping and interfacial effects greatly increases the number of active sites and the activity of the catalyst. This study provides a new pathway for the design of cost-effective, high-performance catalytic materials for overall water splitting.