Abstract
Water splitting for production of hydrogen as a clean energy alternative to fossil fuel has received much attention, but it is still a tough challenge to synthesize electrocatalysts with controllable bonding and charge distribution. In this work, ultrafine S-doped RuP nanoparticles homogeneously embedded in a N, P, and S-codoped carbon sheet (S-RuP@NPSC) is synthesized by pyrolysis of poly(cyclotriphosphazene-co-4,4 '-sulfonyldiphenol) (PZS) as the source of C/N/S/P. The bondings between Ru and N, P, S in PZS are regulated to synthesize RuS2(800 degrees C) and S-RuP (900 degrees C) by different calcination temperatures. The S-RuP@NPSC with low Ru loading of 0.8 wt% with abundant active catalytic sites possesses high utilization of Ru, the mass catalytic activity is 22.88 times than 20 wt% Pt/C with the overpotential of 250 mV. Density functional theory calculation confirms that the surface Ru (-0.18 eV) and P (0.05 eV) are catalytic active sites for the hydrogen evolution reaction (HER), and the according charge redistribution of Ru is regulated by S and P with reverse electronegativity and electron-donor property to induce a synergistically enhanced reactivity toward the HER. This work provides a rational method to regulate the bonding and charge distribution of Ru-based electrocatalysts by reacting macromolecules with multielement of C/N/S/P with Ru.