Support Regulation Strategy Synergistic with Ru Single-Atom Catalyst for Energy-Saving Hydrogen Production Assisted by Green Electrosynthesis of Azotetrazolate

The slow kinetics of the oxygen evolution reaction limits electrochemical overall water splitting (OWS). To address this, integrating thermodynamically favorable organic electro-oxidation with the hydrogen evolution reaction (HER) can enhance the hydrogen production performance. Notably, 5-amino-1H-tetrazole oxidation-assisted OWS not only achieves energy-saving hydrogen production but also produces energetic compound 5,5'-azotetrazolate salts in a mild manner. This necessitates in-depth research into catalysts with straightforward synthesis methods and excellent performance for energy-saving hydrogen production. Supported single-atom catalysts (SACs) have high dispersibility and can reduce the overall use of precious metals. Here, we report a highly efficient HER catalyst consisting of a Ru single atom anchored on low-crystallinity Zn-doped Ni2P nanosheets (Ru-LC-ZNP). The catalyst achieves a low overpotential of 28.9 mV at -10 mA cm-2, demonstrating excellent stability for at least 100 h with no noticeable activity loss. The experimental results indicate that the outstanding alkaline HER performance can be attributed to the synergistic optimization between the Ru single atom and the low-crystallinity support. By coupling water splitting with 5-AT electro-oxidation, the cell voltage of water electrolysis can be enormously reduced to only 1.26 V at 10 mA cm-2. This work provides insights into the mechanism of supported SACs as active HER catalysts.