Advances in etching approaches for synthesis of MAX derived V2CTx MXene and application of V2CTx for green hydrogen production

Abstract

Among two-dimensional (2D) materials, transition metal carbides and nitrides (MXenes) are a prominent family because of their remarkable dispersion in different solvents, flexible surface chemistry, functional transition metal surfaces, higher mechanical strength, and excellent electric conductivities. However, prominent research has been carried out on titanium-based MXene, especially for green H₂ production through photocatalysis and electrochemical approaches, marginalizing the perspective of other MXene sub-families like V₂CT_x. Therefore, this review broadly summarizes the synthesis approach of V₂CT_x from V₂AlC MAX parent material, mainly involving widely used, simple, and facile HF acid and HCl/fluoride salt for in-situ HF generation etching approaches to obtain highly pure V₂CT_x. The most significant properties of V₂CT_x, including electrical, mechanical, and magnetic properties, are discussed, followed by a discussion on the thermal and aqueous solution stability challenges of V₂CT_x. Moreover, the current catalytic material development in terms of green H₂ generation from V₂CT_x-based nanocomposites is discussed for electrochemical and photocatalytic H₂ production applications. Lastly, a detailed conclusion and insight into future perspectives are provided. There is a lack of significant and detailed critical review on the etching approach for the synthesis of pure V₂CT_x and the application of V₂CT_x-based nanocomposites for energy-related applications; thus, this review will aid in the advancement of the utilization of MXenes, especially V₂CT_x for energy-related applications.