Nickel-cobalt phosphate nanoparticles wrapped in nitrogen-doped carbon loading on partially phosphatized foamed nickel as efficient electrocatalyst for water splitting

The progress in the development of 3D self-supporting electrocatalysts is of great significance for the practical application of water electrolysis. In this work, a self-supporting transition metal phosphate was prepared, in which nickel–cobalt phosphate (NixCo1-x(PO3)2) nanoparticles wrapped in nitrogen-doped carbon (NC) were supported on partially phosphatized foamed nickel (P-NF). The particles of ZIF-67-derived Co-N co-doped carbon were fixed on NF by electroplating Ni. The following phosphating led to the NixCo1-x(PO3)2 particles wrapped in NC loading on P-NF ([email protected]/P-NF-e). The NixCo1-x(PO3)2 nanoparticles could effectively afford active sites and exhibited preeminent catalytic activity. Also, NC could improve the electrical conductivity of the sample, accelerate the transfer and transport of charge and prevent the corrosion of electrolyte to NixCo1-x(PO3)2 particles. The [email protected]/P-NF-e catalyst exhibited outstanding catalytic performances for oxygen evolution reaction in 1 M KOH and wide-pH hydrogen evolution reaction. A voltage of 1.50 V was required to reach 10 mA cm−2 for water splitting. Besides, the [email protected]/P-NF-e catalyst showed superior durability for electrolysis of water. The work completed in this study provides a potential methodology for preparing 3D self-supporting phosphate catalysts.