Direct Writing of Oxygen‐Doped Mo ₂ C Enabled by Low‐Temperature Laser Deposition for High‐Performance Acidic Hydrogen Evolution Reaction

Abstract

Abstract Molybdenum carbides have gained tremendous attention for the electrocatalytic hydrogen evolution reaction (HER) due to their high electrical conductivity and similar d‐band structure to platinum. Among molybdenum carbides, Mo 2 C catalysts have exhibited greater potential for acidic HER. However, their performance is restricted by the strong binding interaction between molybdenum and hydrogen. Herein, a series of Mo 2 C catalysts are synthesized using a rapid, low‐temperature laser deposition method to dope oxygen atoms into the Mo 2 C lattices. The metastable oxygen‐doped Mo 2 C exhibits a low overpotential of 125 mV at 10 mA cm −2 , showing significant improvement compared to Mo 2 C (≈182 mV). Density functional theory (DFT) calculations suggest that the introduction of oxygen into the lattices of Mo 2 C can reduce the hydrogen adsorption free energy, indicating that hydrogen production is more favorable on oxygen‐doped Mo 2 C electrocatalyst. At the industrial‐level current density of 1 A cm −2 , the oxygen‐doped Mo 2 C electrocatalyst demonstrates exceptional performance with a low overpotential of 312 mV. Moreover, it exhibits remarkable stability, maintaining consistent hydrogen production for 200 h (>8 days) in 0.5 M H 2 SO 4 , potentially outperforming most non‐noble metal electrocatalysts. This work highlights a new method to synthesize high‐performance transition metal carbide catalysts with a tunable electronic structure to enhance HER performance.