Embedding Mn2Mo3O8/Ni heterojunctions in self-supported lignin-derived carbon frameworks for enhanced ampere-level hydrogen evolution reaction under pH-universal conditions

Biomass-derived carbon-based electrocatalysts often suffer from low performance in hydrogen evolution reaction (HER) at high current density, limiting their industrial use. Herein, a Mn 2 Mo 3 O 8 -Ni heterojunction is integrated into a self-supported lignin-derived carbon framework on nickel foam (LC-Mn 2 Mo 3 O 8 @Ni/NF) to enhance HER performance. Electrochemical tests demonstrate that LC-Mn 2 Mo 3 O 8 @Ni/NF exhibits effective HER activity under pH-universal conditions (Alkali: E -10/−2000  = −54.7/322.9 mV; Acidic: E -10/−2000  = −39.5/431.5 mV; Neutral: E -10/−600  = −84.2/421.9 mV). Density functional theory calculations reveal that the synergy of lignin-derived carbon and the heterojunction redistributes electrons, creating an electron-rich carbon layer and electron-deficient Mn 2 Mo 3 O 8 @Ni, increasing active sites. The optimized d -band center enhances *H adsorption/desorption (ΔG ⁎H  = −0.12 eV) and lowers the water dissociation energy (0.61 eV), facilitating the Volmer step and boosting HER activity across all pH conditions. Furthermore, LC-Mn 2 Mo 3 O 8 @Ni/NF maintains stability at −500 mA cm −2 for 140 h without significant performance loss, attributed to its super-hydrophilic, gas-repellent properties, and corrosion-resistant porous self-supported lignin-derived carbon, thus facilitating HER across pH-universal conditions. This research provides an efficient catalyst for HER and offers valuable insight for developing high-performance biomass-derived carbon-based electrocatalysts for water electrolysis.