An efficient cerium dioxide incorporated nickel cobalt phosphide complex as electrocatalyst for All-pH hydrogen evolution reaction and overall water splitting.

Transition metal phosphides (TMPs) have been considered as potential electrocatalysts with adjustable valence states, metal characteristics, and phase diversity. However, it is necessary but remains a major challenge to obtain efficient and durable TMPs catalysts, which can realize efficiently for not only all-pH hydrogen evolution reaction (HER), but also oxygen evolution reaction (OER). Hence, cerium dioxide incorporated nickel cobalt phosphide growth on nickel foam (CeO2/NiCoP) is fabricated by hydrothermal and phosphating reaction. CeO2/NiCoP shows excellent activity for all-pH HER (overpotentials of 48, 58 and 72 mV in alkaline, neutral and acidic solution at the current density of 10 mA cm-2), and has a small OER overpotential (231 mV @ 10 mA cm-2). Moreover, the voltage of overall water splitting in alkaline solution and simulated seawater electrolyte is only 1.46 and 1.41 V (10 mA cm-2), respectively, coupled with outstanding operational stability and corrosion resistance. Further mechanism research shows that CeO2/NiCoP possesses rich heterointerfaces, which serves more exposed active sites and possesses a promising superhydrophilic and superaerophobic surface. Density functional theory calculations manifest that CeO2/NiCoP has appropriate energy for intermediates of reactions. This work provides a deep insight into the CeO2/NiCoP catalyst for high-performance water/seawater electrolysis.