Carbonized Wood Decorated with Ternary Heterogeneous MoS₂–MoP–Mo₂C Nanoparticles for pH-Universal Hydrogen Evolution

The assembly of diverse active materials significantly enhances the efficiency of the electrocatalytic hydrogen evolution reaction (HER). Herein, we prepare a three-phase composite structure electrocatalyst on carbonized wood, in which molybdenum carbide and molybdenum phosphide are attached to molybdenum sulfide nanosheets (MoS₂-MoP-Mo₂C@CW) through the hydrothermal method in combination with high-temperature calcination for a pH-universal HER. MoS₂ possesses abundant unsaturated coordination edge active sites, thus facilitating the adsorption and desorption of the hydrogen intermediate (H*). The synergistic effect between MoS₂, MoP featuring favorable electronic conductivity, and Mo₂C holding strong adsorption of H* enhances the catalytic activity for the pH-universal HER. Moreover, the carbonized wood with a hierarchical porous structure and aligned microchannels accelerates mass transport during the HER. As a result, the molybdenum-based self-supported composite electrode exhibits outstanding HER performance with the low overpotentials of 46, 84, and 65 mV to achieve the current density of 10 mA cm^-2 and the corresponding Tafel slopes of 57, 111 mV, and 63 mV dec^-1 in alkaline, neutral, and acidic environments, respectively. MoS₂-MoP-Mo₂C@CW also shows a long-term durability of 200 h over a broad pH range at 10 mA cm^-2. This work provides an effective strategy for the development of multiphase carbonized wood-based electrocatalysts for the pH-universal HER.