LAUSR

Abstract 2D transition metal carbides, nitrides and carbonitrides, namely the MXenes, attract more and more attentions due to their unique properties. Here, we report a simple one-step molten salt etching method to prepare Co modified MXene hybrid (Ti3C2Tx:Co) by the reaction of Ti3AlC2 with Lewis acid CoCl2 at 750 °C. Most of Co atoms aggregates in the interlayered space of Ti3C2Tx. Benefitting from the improved electron charge transfer efficiency and increased active sites, the sulfuric acid treated Ti3C2Tx:Co-12h hybrid exhibits excellent electrocatalytical activity for hydrogen evolution reaction in alkaline media, delivering a current density of 10 mA cm−2 at an overpotential of 103.6 mV, which is lower than most noble metal free MXene based electrocatalysts. The results illustrate that the proposed method is very facile and useful to incorporate mid-to-late transition metals into the MXene phase to prepare MXene based HER electrocatalysts.