Construction of MoO2/MoS2 heterojunctions on carbon nanotubes as high-efficiency electrocatalysts for H2 production

Abstract

In this work, we developed an evaporation crystallization method combined with a hydrogen thermal reduction method to construct a MoO₂/MoS₂ heterojunction on carbon nanotubes (denoted as MoO₂/MoS₂@CNT) for hydrogen evolution. In the HER process, the resultant MoO₂/MoS₂@CNT exhibited excellent catalytic activity, which featured a small overpotential of 158 mV at a current density of 10 mA cm⁻² along with a Tafel slope of 70 mV dec⁻¹ as well as excellent stability in 0.5 M H₂SO₄. Experimental findings and theoretical calculations show that the excellent electrocatalytic performance is mainly due to the strong interaction between MoO₂ and MoS₂, which can help to effectively optimize the electronic structure, lower the catalytic energy barrier, and thereby enhance the HER activity. This work provides an effective strategy for constructing a heterojunction to regulate the electron structure, which will generate more inspiration for designing efficient electrocatalysts.