Alleviating the strong hydrogen-bonded interfacial water structure on amorphous Mn-doped RuSe2 nanoparticles deposited on wood-derived carbon for efficient acidic hydrogen evolution

Amorphous Mn-doped RuSe 2 nanoparticles were deposited on the wood-derived hierarchical porous carbon support. • The optimized amorphous (Ru 0.67 Mn 0.33 )Se 2 catalyst requires only 299 mV to deliver 1 A cm −2 in 0.5 M H 2 SO 4 solution. • Ru–Mn electronic coupling enriches the electron density of Ru sites and enhances *H adsorption property. • In situ Raman spectra reveal the enriched population of free-H 2 O accelerating protons transfer. • A solar-powered overall water-splitting device achieves 7.95% STH energy efficiency with excellent stability. The surficial water structure in the electrode/electrolyte double layer governs the transfer rate of protons during the acidic hydrogen evolution reaction (HER). Herein, we introduce the novel strategy to alleviate the strong hydrogen-bonded water structure by doping Mn in the amorphous RuSe 2 nanoparticles deposited on wood-derived carbon for efficient acidic HER. The optimized amorphous (Ru 97.7 Mn 2.3 )Se 2 catalyst requires only 299 mV to deliver 1 A cm −2 in 0.5 M H 2 SO 4 electrolyte, which is comparable to that of the benchmarking commercial Pt/C (20 wt%), and maintains outstanding durability for 100 h at a current density of 100 mA cm −2 . Furthermore, an acidic photovoltaic-driven overall water-splitting system employing amorphous (Ru 0.67 Mn 0.33 )Se 2 catalyst as the cathode achieves a solar-to‑hydrogen energy conversion efficiency of 7.95%. In situ Raman spectra reveal that Mn incorporation reconstructs the interfacial water environment by alleviating the strong hydrogen-bonded interfacial water structure, thereby facilitating protons transfer. Density functional theory (DFT) calculations illuminate that Mn doping induces the upshifting of the d-band center of Ru in amorphous RuSe 2 , which leads to the optimized *H adsorption/desorption thermodynamics. These results demonstrate the synergistic effects of electronic structure regulation and interfacial water structure reconstruction on the amorphous (Ru 97.7 Mn 2.3 )Se 2 catalyst enabling the efficient acidic HER and solar-driven green hydrogen production. Download: Download high-res image (220KB) Download: Download full-size image