Facile synthesis of Co-based selenides for oxygen reduction reaction in acidic medium

Co-based selenides with different selenium contents were successfully synthesized by a one-pot solvothermal method . The physical properties of the prepared catalysts were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis . While their electrocatalytic performances were evaluated by cyclic voltammetry , linear sweep voltammetry , electrochemical impedance spectroscopy and chronoamperometry . The results showed that the Co-Se-75 displayed better electrocatalytic activity towards the oxygen reduction reaction with higher onset potential (0.708 V vs. RHE), reduction current (2.81 mA cm −2 ) and a four-electron oxygen reduction process. Furthermore, the catalyst exhibited better stability, stronger resistance to methanol, ethanol and ethlene glycol than that of the Pt/C (20 wt% Pt) catalyst.