Self-growing NiP2/ZnP4 heterostructured bifunctional catalyst towards overall urea-water electrolysis

Abstract In this paper, Ni2P, ZnP4, and NiP2/ZnP4 are synthesized on nickel foam by two-step method. NiP2/ZnP4/NF is demonstrated to be a better bifunctional catalyst. Furthermore, the effects of calcination temperature on the catalytic performance of Ni2P/ZnP4/NF are studied, they are synthesized at different temperatures (250 °C, 300 °C, 350 °C) (denoted as Ni2P/ZnP4/NF-250, Ni2P/ZnP4/NF-300, Ni2P/ZnP4/NF-350). The results indicate Ni2P/ZnP4/NF-300 has better catalytic performance, and can be used as bifunctional catalyst for both HER and UOR in alkaline electrolyte. Then, a two-electrode electrolyzer Ni2P/ZnP4/NF-300||Ni2P/ZnP4/NF-300 is constructed. It only needs 1.69 V at 50 mA cm−2 with long-term stability. Thus, Ni2P/ZnP4/NF-300 is not only promising for hydrogen production, but also has great significance for urea-water treatment.