Hollow nanosphere Fe-Cu-Co trimetallic selenides with high catalytic performances for hydrogen evolution reaction in both acidic and alkaline electrolytes

Developing non-precious metal based catalysts is one of the most feasible ways to accelerate the application of hydrogen production technology by full water electrolysis with low-cost and high efficiency. In this work, hollow nanosphere structured Fe–Cu–Co trimetallic selenide based catalysts were successfully prepared by one-step hydrothermal method. The hollow nano-spherical shell structure was examined by using XRD, Raman, BET, SEM, TEM, XPS, etc. technologies. The catalytic performance for hydrogen evolution reaction (HER) of the catalysts was tested by LSV, Tafel, CV, EIS, i-t , etc . methods. The overpotential of FeCo 0.1 Cu 0.9 Se 2 catalyzed HER was only 191 (alkaline) and 112 mV (acidic) at 10 mA/cm 2 . The corresponding Tafel slope for HER is 180 mV/dec (alkaline) and 110 mV/dec (acidic), respectively. In addition, the FeCo 0.1 Cu 0.9 Se 2 also showed excellent long-time running stability. The current decay after continuous running 12 h in 0.5 M H 2 SO 4 and 0.1 M KOH electrolytes are 0.07 % and 0.271 %, respectively. FeCo 0.1 Cu 0.9 Se 2 catalyst with the hollow nanospherical structure exhibited excellent catalytic activity for HER. Density functional theory calculations show that the introduction of Co and Cu adjusted the electronic structure of FeCo 0.1 Cu 0.9 Se 2 and the special hollow nano-spherical structure provides enough active catalytic sites for HER. The nano-spherical structured multi-metal selenides show great potential to be high performance catalysts for HER in both alkaline and acidic electrolytes.