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 Ti3C2Tx MXene, 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 mV, a small Tafel slop of 76 mV dec(-1) as 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. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.