Bio-inspired design of NiFeP nanoparticles embedded in (N,P) co-doped carbon for boosting overall water splitting.

The design and synthesis of cost-effective and stable bifunctional electrocatalysts for water splitting a green and sustainable fabrication way remain a challenging problem. Herein, a bio-inspired method was used to synthesize NiFeP nanoparticles embedded in (N,P) co-doped carbon with the added carbon nanotubes. The obtained NiFeP-C catalyst displayed excellent hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performances in both alkaline and alkaline simulated seawater solutions. The optimal NiFeP-C/NF only needs overpotentials of 45 and 242 mV to reach the current density of 10 mA cm under HER and OER working conditions in 1.0 M KOH solution, respectively. First-principles calculations revealed the presence of a strong interaction between the carbon layer and metal phosphide nanoparticles. Benefiting from this and carbon nanotubes modification, the fabricated NiFeP-C presents impressive stability, working continuously for 100 h without collapse. A low alkaline cell voltage of 1.56 V for the assembled NiFeP-C/NF//NiFeP-C/NF electrocatalyzer could afford a current density of 10 mA cm. Moreover, when integrated with a photovoltaic device, the bifunctional NiFeP-C electrocatalyst demonstrates application potential for sustainable solar-driven water electrolysis.