Construction of Co-decorated 3D nitrogen doped-carbon nanotube/Ti3C2Tx-MXene as efficient hydrogen evolution electrocatalyst

Abstract

Rational design of transition metal catalysts with robust and durable electrocatalytic activity for hydrogen evolution reactions (HER) is extremely important for renewable energy conversion and storage, as well as water splitting. Heteroatom doping has emerged as a feasible strategy for enhancing electrocatalytic activity. Here, cobalt nanoparticles (Co-NPs) were coated with nitrogen-doped carbon nanotubes (NCNTs) prepared via an in situ growth on accordion-like Ti3C2Tx-MXene (Co-NCNT/Ti3C2Tx). Such an intriguing structure showed great features: abundant anchoring sites for NCNT in situ growth, intimate integration of Co-NPs and NCNTs, high-speed electron transfer between 1D NCNTs and 2D Ti3C2Tx-MXenes, and a large number of effective catalytic active sites. This Co-NCNT/Ti3C2Tx hybrid catalyst was demonstrated to possess excellent HER performance with low overpotential (η10, 190 mV), small Tafel slope (78.4 mV dec−1), large electrochemically active surface area, and good long-term stability, thus outperforming many reported electrocatalysts. The present strategy provided a facile route for the design of transition metal HER catalysts with NCNT and MXene.