Engineering Thin MoS2 Nanosheets on TiN Nanorods: Advanced Electrochemical Capacitor Electrode and Hydrogen Evolution Electrocatalyst

Abstract

The poor intrinsic conductivity of MoS₂ presents a huge barrier for the exploitation of its versatile properties, especially as an electrochemical capacitor (EC) electrode and hydrogen evolution reaction (HER) catalyst. Toward this challenge, TiN nanorods coated by randomly oriented MoS₂ nanosheets (TMSs) are engineered as state-of-the-art electrodes for ECs and HER. In light of the synergistic effects, TMS electrodes show favorable performance as both a binder-free EC electrode and HER catalyst. Importantly, the optimal TMS achieves an areal capacitance of 662.2 mF cm^–2 at 1 mA cm^–2 with superior rate capability and ultralong cycling stability. As the catalyst for HER in 0.5 M H₂SO₄, it shows an overpotential of 146 mV at 10 mA cm^–2, a favorable Tafel slope, and good electrocatalytic stability. All of the results highlight the favorable integration of TiN and MoS₂ and provide clear insight correlating the hybrid structure and the corresponding electrochemical performance.