Cobalt-doped edge-rich MoS2/nitrogenated graphene composite as an electrocatalyst for hydrogen evolution reaction

Co-doped MoS2/nitrogenated graphene composite has been successfully fabricated through a facile hydrothermal method and is investigated as an electrocatalyst for hydrogen evolution reaction (HER). The results reveal that Co2+ ions have been successfully incorporated into MoS2 lattice which can give rise to structural strain and dislocation. As a result, the Co-doped MoS2 nanosheets are characteristic of few layers (3-6 layers) and abundant exposed active edges. Meanwhile, Co-doped MoS2 nanosheets are well implanted into the nitrogen-doped graphene networks to form robust composite. When evaluated as a catalyst for HER, the obtained composite demonstrates superior electrocatalytic activities towards HER including low onset potential (similar to 90 mV), large cathodic current density and small Tafel slope of 59 mV dec(-1). It is believed that the desirable catalytic properties can be credited to the unique microstructures including few-layer features, plentiful exposed active sites as well as intimate integration with highly electroconductive nitrogenated graphene. (C) 2016 Elsevier B.V. All rights reserved.