Fig. 3
Electrochemical hydrogen evolution reaction (HER) performance. a HER polarization curves of np-Co0.85Se, Pt/np-Co0.85Se and Pt/C. b Corresponding to Tafel plots of the presented data in a. c Corresponding to onset potential at −1 mA cm−2 of the presented data in a. d The mass activity of Pt/np-Co0.85Se and state-of-the-art Pt/C. e Comparison of merit with respect to both kinetics (Tafel slope) and activity (the overpotential required to achieve −10 mA cm−2), with references all measured in neutral medium. f TOF values of Pt/np-Co0.85Se (red dot), together with previous reported HER electrocatalysts at −100 mV vs. RHE. g Faradaic efficiency of Pt/np-Co0.85Se at different applied potentials. h The detail of hydrogen Faradaic efficiency measurement. i Accelerated HER polarization curves of Pt/np-Co0.85Se. j Current density vs. time (i–t) curves of Pt/np-Co0.85Se recorded for 40 h s at −50 mV vs. RHE
