Single Atom Ru Doped Ni 2 P/Fe 3 P Heterostructure for Boosting Hydrogen Evolution for Water Splitting.

Modulating the chemical composition and structure has been considered as one of the most promising strategies for developing high-efficient water splitting catalysts. Here, a single-atom Ru doped Ni 2 P/Fe 3 P catalyst is synthesized by introducing the dispersed Ru atoms to adjust Ni 2 P/Fe 3 P heterostructure. Single atom Ru provides effective hydrogen evolution reaction (HER) active sites for boosting catalytic activities. The catalyst with only 0.2 wt.% content of Ru exhibits an overpotential of 19.3 mV at 10 mA cm -2 , which is obviously lower than 146.1 mV of Ni 2 P/Fe 3 P. Notably, an alkaline overall water electrolyzer based on Ru-Ni 2 P/Fe 3 P catalysts achieves a cell voltage of 1.47 V and operates over 600 h at 10 mA cm -2 , which is superior to that of benchmark RuO 2 //Pt/C (1.61 V). The theoretical calculations further confirm that Ru single atom doping can effectively optimize the hydrogen/water adsorption free energy of the active site and therefore improve the HER activity of heterostructure. This work provides a valuable reference to design high-activity and durability catalyst for water splitting through the double modulation of interface-effect and atomic doping.