Atomic Dispersion of Rh on Interconnected Mo₂C Nanosheet Network Intimately Embedded in 3D Ni_xMoO_y Nanorod Arrays for pH-Universal Hydrogen Evolution

Herein, a simple synthetic approach is employed for the atomic dispersion of Rh atoms (Rh SAs) over the surface of interconnected Mo₂C nanosheets intimately embedded in a three-dimensional Ni_xMoO_y nanorod arrays (Ni_xMoO_y NRs) framework; we found that the introduction of both isolated Rh SAs and Ni_xMoO_y NRs adjusts the electrocatalytic function of the host Mo₂C toward the direction of being an advanced and highly stable electrocatalyst for efficient hydrogen evolution at pH-universal conditions. As a result, the proposed catalyst outperforms most recently reported transition metal-based catalysts, and its performance even rivals that of commercial Pt/C, as demonstrated by its ultralow overpotentials of 31.7, 109.7, and 95.4 mV at a current density of 10 mA cm⁻², along with its small Tafel slopes of 42.4, 51.2, and 46.8 mV dec⁻¹ in acidic, neutral, and alkaline conditions, respectively. In addition, the catalyst shows remarkable long-term stability over all pH values with good maintenance of its catalytic activity and structural characteristics after continuous operation.