Interface and doping engineering of V2C-MXene-based electrocatalysts for enhanced electrocatalysis of overall water splitting

Abstract

The restacking and oxidizable nature of vanadium-based carbon/nitride (V₂C-MXene) poses a significant challenge. Herein, tellurium (Te)-doped V₂C/V₂O₃ electrocatalyst is constructed via mild H₂O₂ oxidation and calcination treatments. Especially, this work rationally exploits the inherent easy oxidation characteristic associated with MXene to alter the interfacial information, thereby obtaining stable self-generated vanadium-based heterointerfaces. Meanwhile, the microetching effect of H₂O₂ creates numerous pores to address the restacking issues. Besides, Te element doping settles the issue of awkward levels of absorption/desorption ability of intermediates. The electrocatalyst obtains an unparalleled hydrogen evolution reaction and oxygen evolution reaction with the overpotential of 83.5 and 279.8 mV at −10 and 10 mA cm⁻², respectively. In addition, the overall water-splitting device demonstrates a low cell voltage of 1.41 V to obtain 10 mA cm⁻². Overall, the inherent drawbacks of MXene can be turned into benefits based on the planning strategy to create these electrocatalysts with desirable reaction kinetics.