Rationally engineered active sites for efficient and durable hydrogen generation.

The atomic-level understanding of the electrocatalytic activity is pivotal for developing new metal-free carbon electrocatalysts towards efficient renewable energy conversion. Here, by utilizing the amidated-carbon fibers, we demonstrate a rational surface modulation strategy on both structural and electronic properties, which will significantly boost the hydrogen evolution reaction activity of electrocatalysts. Theoretical calculations reveal the amidation decorated surface will promote significantly more 2D electrons towards the localization at the C=O branch. The modified surface displays a self-activated electron-extraction characteristic that was actualized by a fast reversible bond-switching between HO-C=C and O=C-C. Experimentally, this metal-free electrode exhibits outstanding hydrogen evolution reaction activities and long-term stabilities in both acidic and alkaline media, even surpassing the commercial 20 wt% Pt/C catalyst. Thus, this strategy can extend to a general blueprint for achieving precise tuning on highly efficient electron-transfer of hydrogen evolution reaction for broad applications under universal pH conditions.