Bottom-up construction of three-dimensional porous MXene/nitrogen-doped graphene architectures as efficient hydrogen evolution electrocatalysts.

The exploration of highly-active non-platinum electrocatalysts with low-cost has been regarded as a crucial way to alleviate the major bottleneck in electrocatalytic hydrogen evolution reaction (HER) technology. Herein, we demonstrate the bottom-up construction of three-dimensional (3D) hybrid architectures built from Ti 3 C 2 T x MXene and nitrogen-doped graphene nanosheets (MX/NG) through a facile and cost-effective co-assembly approach. The as-derived MX/NG architectures are endowed with a number of distinctive structural advantages, such as large specific surface areas, 3D cross-linked porous frameworks, ultrathin walls, optimized electronic structures, and good electron conductivity. As a result, exceptional HER performances with a relatively low onset potential, a small Tafel slope, and reliable long-term stability are achieved on the optimized MX/NG electrode, markedly outperforming those of bare Ti 3 C 2 T x and NG electrodes. The controllable construction of 3D hybrid architectures built from Ti 3 C 2 T x MXene and nitrogen-doped graphene nanosheets is achieved by a bottom-up co-assembly method. By virtue of the porous networks and optimized electronic structure, the resulting 3D architectures exhibit superior electrocatalytic properties toward hydrogen evolution reaction. [Display omitted] • The 3D MXene/N-doped graphene architectures are constructed by a bottom-up approach. • The 3D porous network provides accessible pores for the fast electrolyte transport. • The optimized electronic structure endows the hybrid with numerous active sites. • The resulting architectures show superior electrocatalytic ability towards HER. [ABSTRACT FROM AUTHOR]