Vanadium-doped MoSe2 Nanosheets: Induced lattice contraction and enhanced conductivity for superior hydrogen evolution reaction

In the modern world with a growing global energy demand, renewable hydrogen has emerged as a viable and attractive option. Herein, a highly efficient electrocatalyst for the hydrogen evolution reaction (HER) in an acidic medium was designed by doping MoSe 2 with vanadium (V-MoSe 2 ). The V-doped MoSe 2 was formed using a simple hydrothermal reaction and characterised using FE-SEM, FE-TEM, XRD and XPS. The V-MoSe 2 was superior to MoSe 2 and comparable to Pt/C in the HER. An overpotential of 217 mV for Pt/C and 353 mV for V-MoSe 2 was required to deliver a current density of 10 mA/cm 2 . This enhanced HER activity seen with V-MoSe 2 was attributed to a lattice contraction, a more metallic-like phase with enhanced electrical conductivity, and an increase in the density of catalytically active sites that promote the HER. • Doping of MoSe 2 with V leads to lattice contraction and an increase in conductivity. • The V-MoSe 2 adopts a wrinkled and rippled surface morphology with a high ESCA. • V-MoSe 2 facilitates the hydrogen evolution reaction in acidic media.2