Unraveling the synergistic mechanism of N-CNT/Co@MoS₂ heterostructure for pH-universal hydrogen evolution reaction

Despite being a new class of low-cost base-metal catalysts for the hydrogen evolution reaction (HER), Mo-based compounds, such as MoS_2, still exhibit relatively low catalytic activity. To improve the low activity of MoS₂, considerable attention has been paid to defect engineering, nanostructure management, and doping with precious and non-precious metals. However, further studies are still required to enhance the catalytic activity of MoS₂ for practical electrochemical applications. In this study, to enhance the activity of MoS₂ by constructing the heterostructure between N-doped CNTs (N-CNTs) and MoS₂, pristine MoS₂ was synthesized to prepare electrodes for electrochemical hydrogen generation that showed exceptional performance in both acidic and basic environments. N-CNTs containing Co were also grown directly on carbon cloths to greatly increase the electrode surface area. By designing this N-CNTs and MoS₂ heterostructure, the produced hydrogen adsorption energy of the catalysts was considerably lower than that of pure MoS₂. Thus, in both acidic and alkaline environments, the electrode demonstrated a low overpotential (η₁₀) value of 75 and 127 mV, respectively, demonstrating outstanding HER performance. Moreover, the prepared system not only improves the performance of MoS₂ but also holds great promise for enhancing the activity of various noble- and non-noble-metal-based electrochemical hydrogen evolution catalysts. A new avenue for creating high-performance electrochemical electrodes for water splitting is made possible by this discovery.