N-doped carbon nanosheets packaged ultra-small FeCoP toward efficient water splitting

Iron phosphide (FeP) has garnered significant attention due to its abundant iron reserves, low cost and impressive hydrogen evolution reaction (HER) activity. Nevertheless, sluggish charge transport, large particle size and poor oxygen evolution reaction (OER) activity make it still difficult to meet the desired practical applications. As we know, heterogeneous element doping, porous two-dimensional structure design, and nanoconfinement control can effectively improve the mass/charge transfer rate and expose more active sites. Hence, ultra-small bimetallic iron-cobalt phosphide nanoparticles encapsulated and dispersed in two-dimensional nitrogen-doped carbon nanosheet (FeCoP@NC) catalysts were successfully constructed. The optimized FeCoP@NC shows outstanding electrocatalytic stability and activity toward OER and HER under alkaline conditions. The overall water splitting performance was further measured by using FeCoP@NC as both anode and cathode, which also delivers good performance indicators. This work provides a new perspective and potential value for the rational design of non-precious metal bifunctional catalysts.