Nitrogen doped FeS2 nanoparticles for efficient and stable hydrogen evolution reaction

Performance breakthrough of electrocatalysts highly relies on the regulation of internal structures and electronic states. In present work, for the first time, we successfully synthesized nitrogen doped FeS2 nanoparticles(N-FeS2) as the electrocatalysts for hydrogen evolution reaction(HER). The band structure and electronic state of FeS2 are modulated by a nitrogen doping strategy, as confirmed by X-ray photoelectron spectroscopy(XPS), X-ray absorption spectroscopy(XAS) and density functional theory(DFT)calculations. Owing to the band structure and electronic state regulation as well as the weakening of HàS interaction, the designed N-FeS2 electrocatalyst exhibits superior catalytic performance with a low overpotential(～126 mV at 10 mA cmà2) and excellent activity stability under alkaline conditions,which is substantially improved as compared with that of the pure FeS2 counterpart. Our work demonstrates that the modulation of electron state and band structure of an electrocatalyst, which can provide a valuable guidance for designing excellent catalysts for hydrogen evolution reaction and beyond.