Asymmetric electronic structure at the interface Ni-P-Ru bridge inducing dual active sites for electrocatalytic urea-assisted water splitting

It is an efficient strategy to introduce dual active sites into alkaline urea-assisted water electrolysis systems by interfacial coupling, but it still poses certain challenges. In this study, Ni 2 P-RuP 2 /C with hollow sphere structure is designed and synthesized by using solvothermal, ion exchange and one-step phosphating strategy. Studies utilizing density functional theory (DFT) and Synchrotron radiation show that Ni-P-Ru bridge in Ni 2 P-RuP 2 /C acts as an electron transport pathway that promotes localized charge redistribution, causing electrons to flow from Ni 2 P/C to RuP 2 /C, optimizing the d-band center and reducing the reaction barrier of HER and UOR. It is determined that the electron-rich Ru sites favor proton adsorption and the electron-deficient Ni sites favor the adsorption of urea molecules and the release of CO 2 which become the true active sites of HER and UOR, respectively. The optimized Ni 2 P-RuP 2 /C need merely 13 mV and 1.314 V to attain 10 mA cm −2 for HER and UOR, respectively. This study provides a reliable pathway for green hydrogen production through the construction of Ni-P-Ru bridge.