Vertically aligned MoS2 on Ti3C2 (MXene) as an improved HER catalyst

Abstract

We have demonstrated the microwave-assisted growth of vertically aligned interlayer expanded MoS₂ on conductive two-dimensional Ti₃C₂ MXene nanosheets (MoS₂⊥Ti₃C₂) and investigated the produced material as an electrocatalyst for the hydrogen evolution reaction (HER). MoS₂⊥Ti₃C₂ offers a unique inorganic hybrid structure that allows increased exposure of catalytically active edge sites of MoS₂, compared to pure MoS₂ with a platelet-like morphology. The vertically aligned few-layer MoS₂ sheets have an expanded interlayer spacing of 9.4 Å. The MoS₂⊥Ti₃C₂ catalyst exhibited a low onset potential (−95 mV vs. RHE) for the HER and a low Tafel slope (∼40 mV dec⁻¹). This catalyst maintained a steady catalytic activity for the HER for over 20 hours.