Ionic liquid-assisted controlled synthesis of multi-site Ni 2 P as a bifunctional catalyst for electrocatalytic water splitting

It is crucial to develop effective electrocatalysts with multiple active sites for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in order to promote the advance energy conversion and development of sustainable energy technology. Here, we synthesized hierarchical nanostructured Ni 2 P on carbon cloth using ionic liquid (IL) assisted sacrificial template strategy through a simple two-step hydrothermal phosphatization process, which served as an electrode for enhancing bifunctional water electrolysis. By changing the content of ionic liquids in the solvent, the morphology of Ni(OH) 2 precursors could be regulated, thereby altering the morphology of Ni 2 P. Ni 2 P exhibited remarkable electrocatalytic activity towards HER in acidic electrolytes with an overpotential of 132 mV at a current density of 10 mA cm −2, as well as OER in alkaline media with the overpotential of 309 mV. The excellent electrocatalytic activity of the Ni 2 P-2 could be attributed to its hierarchical nanostructure providing abundant active sites, which benefits from the structural end-capping effect of ILs.