Constructing 3D interweaved MXene/graphitic carbon nitride nanosheets/graphene nanoarchitectures for promoted electrocatalytic hydrogen evolution

The technique of electrocatalytic hydrogen evolution reaction (HER) represents a development trend of clean energy generation and conversion,while the electrode catalysts are bound to be the core unit in the electrochemical HER system.Herein,we demonstrate a bottom-up approach to the construction of three-dimensional (3D) interconnected ternary nanoarchitecture originated from Ti3C2TxMXene,graphitic carbon nitride nanosheets and graphene (MX/CN/RGO) through a convenient co-assembly process.By virtue of the 3D porous frameworks with ultrathin walls,large specific surface areas,optimized electronic structures,high electric conductivity,the resulting MX/CN/RGO nanoarchitecture expresses an exceptional HER performance with a low onset potential of only 38 m V,a small Tafel slop of 76 m V dec-1as well as long lifespan,all of which are more competitive than those of the bare Ti3C2Tx,g-C3N4,graphene as well as binary MX/RGO and CN/RGO electrocatalysts.Theoretical simulations further verify that the ternary MX/CN/RGO nanoarchitecture with ameliorative band structure is able to facilitate the electron transport and meanwhile offer multistage catalytically active sites,thereby guaranteeing rapid HER kinetics during the electrocatalytic process.