Integration of amorphous CoSnO3 onto wrinkled MXene nanosheets as efficient electrocatalysts for alkaline hydrogen evolution

Two-dimensional (2D) MXenes-based nanostructures have recently emerged as effective electrocatalysts because of their excellent electrical conductivity and superior hydrophilicity. Nevertheless, the low electrocatalytic ac-tivity and the poor stability have hampered their applications in practical hydrogen production. Herein, a novel method to modulate the electronic structure and improve the catalytic activity of MXene by integrating amor-phous CoSnO3 onto wrinkled Ti3C2Tx MXene nanosheets is reported, producing a promising electrocatalyst (MXene@CoSnO3) toward alkaline hydrogen evolution reaction (HER). It is found that CoSnO3 nanocubes are well grown on the surface of Ti3C2Tx MXene, stabilizing MXene nanosheets against spontaneous oxidation. More importantly, the strong interfacial electronic coupling between the two components greatly prompts the redis-tribution of electrons at the MXene and CoSnO3 interfaces and alters the electronic structure around Co, which enables the activation of high-potential Sn to have an optimal *H adsorption (Delta G*H), promoting the H* con-version for HER. The fabricated MXene@CoSnO3 exhibits high alkaline HER performances with an ultralow overpotential of 45 mV at 10 mA cm-2, a small Tafel slope of 51 mV dec-1 and the long-term stability in 1 M KOH, which even compares with commercial Pt/C catalyst.