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–NiS 2 /CeO 2 nanosheets grown on foamed nickel (Co–NiS 2 /CeO 2 /NF) are prepared by hydrothermal reaction and annealing. The Co–NiS 2 /CeO 2 /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–NiS 2 /CeO 2 /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. Co-doped and CeO 2 heterostructure modified NiS 2 grown on foamed nickel electrocatalyst is successfully constructed through a simple hydrothermal process followed by further vulcanization treatment and exhibits excellent electrocatalytic performance and stability towards overall water splitting. In 1.0 M KOH solution, the current densities of the HER and OER can reach 10 mA cm−2 with minimum overpotentials of 88 mV and 240 mV, respectively. Additionally, when a standard two-electrode water electrolyzer is fabricated by employing Co–NiS 2 /CeO 2 /NF as both the cathode and anode, it can generate 10 mA cm−2 at 1.38 V and operate steadily without performance degradation after 48 h. [Display omitted] • The combination of doping and interfacial effects greatly increases the activity of the catalyst. • Co–NiS 2 /CeO 2 /NF exhibits excellent activity towards overall water splitting. • Co–NiS 2 /CeO 2 /NF shows a remarkably stability with a nearly unchanged potential after a longer stability test. [ABSTRACT FROM AUTHOR]