Facile synthesis of cobalt modified 2D titanium carbide with enhanced hydrogen evolution performance in alkaline media

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 (Ti₃C₂T_x:Co) by the reaction of Ti₃AlC₂ with Lewis acid CoCl₂ at 750 °C. Most of Co atoms aggregates in the interlayered space of Ti₃C₂T_x. Benefitting from the improved electron charge transfer efficiency and increased active sites, the sulfuric acid treated Ti₃C₂T_x: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.