Phosphorus doped nickel selenide for full device water splitting.

Self-supported P doped NiSe 2 and NiSe 2 were synthesized through a selenylation process by using nickel foam as precursor. The P doping leads to the increase electrochemical activities for water splitting. [Display omitted] The lack of high active and stable electrocatalysts has impeded the development of electrochemical water splitting device, which is promising technique for renewable energy conversion system. Here, we report a one-step protocol to synthesize P doped NiSe 2 (P-NiSe 2) by selenylation process derived from nickel foam with assistant of NaH 2 PO 2 and Se powder. The P-NiSe 2 could be directly used as working electrode and shows the superior electrochemical activity, offering current density of 10 mA cm−2 with overpotential of 270 mV for OER and 71 mV for HER. The enhanced electrochemical activity can be ascribed to the P atom doping. The P atom doping leads to the high valence state of Ni active sites, which have high catalytic ability towards OER. Moreover, the P doping makes the d -band center of Ni atoms in P-NiSe 2 move close to Fermi level, facilitating the HER kinetics with respect to proton adsorption and hydrogen desorption. When employed P-NiSe 2 as both anodic and cathodic electrode in alkaline water electrolyzer, a current density of 10 mA cm−2 can be achieved at 1.58 V. Our work highlights the importance of P doping in determining the surface electron configuration for full device water splitting and the facile synthesis protocol would be promising for realistic applications. [ABSTRACT FROM AUTHOR]