Facile, general and environmental-friendly fabrication of O/N-codoped porous carbon as a universal matrix for efficient hydrogen evolution electrocatalysts.

[Display omitted] • A general but efficient "three-in-one" synthetic strategy for PCMs was developed. • Pyrolysis of EDTA-4Na in air led to AC with more oxygenated groups and mesopores. • As-formed AC was a universal carrier for selected Pt group metal (Ru, Rh, Ir) NPs. • The optimal Ru/AC had the highest HER activity with a low overpotential of 7 mV. • The small Ru NPs with electron-rich sites contributed to the high performance. Heteroatom-doped porous carbons are widely exploited as efficient matrices to stabilize metal nanoparticles (NPs) for electrocatalysis, whereas their syntheses without additional activation and functional agents and inert gases still remains a grand challenge. Herein, we report the simple yet efficient inert gas-free direct fabrication of hierarchically porous interconnected O/N-codoped carbon nanosheets (designated as AC) and their application as excellent matrices for preparing selected Pt group metal (Ru, Rh, Ir) electrocatalysts toward alkaline hydrogen evolution reaction (HER). The self-templating, self-activation and in-situ O/N-functionalization synthesis of AC is achieved via the one-pot pyrolysis of ethylenediaminetetraacetic acid tetra-sodium without additional inert gas. Compared with NC prepared via annealing the same precursor in N 2 atmosphere, the as-formed AC with more mesoporous structure and oxygenated functional groups enables the fabrication of smaller and electron-rich Ru NPs, which deliver an optimal HER activity in terms of an extremely low overpotential of 7 mV at 10 mA cm−2 for HER, superior to that of Rh/AC, Ir/AC, Ru/NC, commercial Pt/C and plenty of previously fabricated Ru-based electrocatalysts. This "three-in-one" synthetic method demonstrates superior generality for other porous carbon materials by using potassium gluconate and potassium sodium tartrate as precursors. [ABSTRACT FROM AUTHOR]