Research progress in application of two-dimensional nanomaterials MXenes and its composites in electrocatalysis field

MXenes, as a new 2D transition metal carbides/nitrides/carbonitrides, have wide potential application in physics,chemistry,material science and nanotechnology fields. Since MXenes inevitably possess defects and -O, -OH, -F terminal groups during the preparation, behaving high conductivity and large surface area, MXenes have a good electron transfer rate and can be used as an excellent electrochemical catalyst. In this review, the various synthesis methods and development of different doping types of MXenes were introduced. The application and mechanism of MXenes in electrocatalytic hydrogen production, oxygen production, oxygen reduction, CO2 reduction and nitrogen reduction processes were mainly discussed. It was pointed out that the preparation methods of MXenes should possess the characteristics of environmental friendliness, morphology controllability, the inoxidizability and high adjustability, meanwhile, different types of MXenes should be applied to different electrocatalytic reactions.