Dual-Phase MoS$_2$ And MXene Nanohybrids for Efficient Electrocatalytic Hydrogen Evolution

TL;DR

This study develops a dual-phase MoS2 and MXene nanohybrid catalyst with enhanced electrical conductivity and active sites, achieving efficient hydrogen evolution with low overpotential and high stability, advancing PGM-free electrocatalysts.

Contribution

A novel one-step synthesis method creating MoS2/MXene nanohybrids with improved electrocatalytic performance for HER.

Findings

Achieved low overpotential of 169 mV for HER.

Demonstrated enhanced electrical conductivity and stability.

Produced catalysts with low Tafel slope of 51 mV/dec.

Abstract

Molybdenum Disulfide (MoS$_2$) has been recognized as a potential substitution of Platinum (Pt) for electrochemical hydrogen evolution reaction (HER). However, the broad adoption of MoS$_2$ is hindered by its limited number of active sites and relatively low inherent electrical conductivity. In this work, we demonstrated a synergistic enhancement of both active site exposure and electrical conductivity by a one-step solvothermal synthesis technique. The 1T-phase enriched MoS$_2$ was directly formed on the titanium carbide (Ti$_3$C$_2$Tx, MXene) with carbon nanotubes (CNTs) acting as crosslinks. The existence of edge-enriched metallic phase MoS$_2$, the conductive backbone of MXene along with the crosslinking function of CNTs clearly improved the overall electrical conductivity of the catalyst. Moreover, the integration of two-dimensional (2D) MoS$_2$ with MXene effectively suppressed the MXene oxidation and 2D layer restacking, leading to good catalytic stability. As a result, an overpotential of 169 mV and a low Tafel slope of 51 mV/dec was successfully achieved. This work provides a new route for 2D-based electrocatalyst engineering and sheds light on the development of the next-generation PGM-free HER electrocatalysts.