Engineering P-Fe2O3-CoP nanosheets for overall freshwater and seawater splitting

Tailoring surface composition and coordinative environment of catalysts in a nano-meter region often influence their chemical performance. It is reported that CoP exhibits a low dissociation ability of H-OH, originating from the poor desorption of intermediate species. Herein, we provide a feasible method to construct P-Fe2O3-CoP nanosheets through a gas-phase phosphorization process. P doping induces the formation of interfacial structure between Fe2O3 and CoP and the generation of defective structures. The resulting P-Fe2O3-CoP nanosheets afford high freshwater/seawater oxidation activity (250/270 mV@10 mA/cm2) in 1 mol/L (M) KOH, which is even lower than commercial RuO2. Compared with CoP||CoP, P-Fe2O3||P-Fe2O3, and Co3O4||Co3O4, the assembled PFe2O3-CoP||P-Fe2O3-CoP exhibits the superior water/seawater electrolysis performance with 1.61/1.65 V@10 mA/cm2. The synergistic effect of P doping, defective structure, and heterojunction leads to high water oxidation efficiency and water splitting efficiency.

Automated summary

Tailoring the surface composition and coordinative environment of catalysts can influence their chemical performance. In this study, P-Fe2O3-CoP nanosheets were successfully constructed using a gas-phase phosphorization process. The P doping induced the formation of interfacial and defective structures between Fe2O3 and CoP, resulting in high oxidation and electrolysis activity in alkaline conditions.