Synthesis and properties towards oxygen reduction reaction of transition metal selenides

In this work, Ni-Se-x (x is the feed ratios) (x = 30, 40, 45, 50.5, 55, 56.8, 60, 66.7, 80) is synthesized by a solvothermal method. The scanning electron microscopy shows that the Ni-Se-60 exhibits a fluffy petal-like surface. Electrochemical tests, such as cyclic voltammetry, electrochemical impedance spectra, liner sweep voltammetry, and chronoamperometry, show that the catalytic activity of Ni-Se-60 towards oxygen reduction reaction is better than that of other transition metal selenides. Ni-Se-60 has obvious redox peak (peak potential is 0.31 V), higher initial potential (0.739 V) and half-wave potential (0.568 V), lower charge transfer resistance, and better stability. Furthermore, Ni-Se-60 has better tolerance to methanol, ethanol, and ethylene glycol than Pt/C.