Awakening the oxygen evolution activity of MoS2 by oxophilic-metal induced surface reorganization engineering

Abstract Although molybdenum disulfide (MoS2)-based materials are generally known as active electrocatalysts for the hydrogen evolution reaction (HER), the inert performance for the oxygen evolution reaction (OER) seriously limits their wide applications in alkaline electrolyzers due to there exists too strong metal-sulfur (M−S) bond in MoS2. Herein, by means of surface reorganization engineering of bimetal Al, Co-doped MoS2 (devoted as AlCo3-MoS2) through in situ substituting partial oxidation, we successfully significantly activate the OER activity of MoS2, which affords a considerably low overpotential of 323 mV at −30 mA cm−2, far lower than those of MoS2, Al-MoS2 and Co-MoS2 catalysts. Essentially, the AlCo3-MoS2 substrate produces lots of M−O (M=Al, Co and Mo) species with oxygen vacancies, which trigger the surface self-reconstruction of pre-catalysts and simultaneously boost the electrocatalytic OER activity. Moreover, benefiting from the moderate M−O species formed on the surface, the redistribution of surface electron states is induced, thus optimizing the adsorption of OH* and OOH* intermediates on metal oxyhydroxides and awakening the OER activity of MoS2.