Effect of metal hexacyanoferrate films on hydrogen evolution reaction

► The effect of single and mixed metal hexacyanoferrates on electrochemical hydrogen evolution was studied. ► Electrodeposition of metal hexacyanoferrates is easy and cheap. ► These mediators improve the current density, and reduce the overvoltage of hydrogen evolution reaction. ► Among 13 studied mediators, Ni-PbHCF has the best performance.