Self-supported bimetallic phosphide-carbon nanostructures derived from metal-organic frameworks as bifunctional catalysts for highly efficient water splitting

Abstract

Nanostructured transition-metal phosphides (TMPs) have recently emerged as a new family of non-noble-metal catalysts to drive water splitting due to their unique electronic and redox properties. However, most progress focused on developing mono-metal phosphide nanostructures. In this work, a facile template-based method and low-temperature phosphorization process are proposed to fabricate self-supported Ni-based bimetallic phosphide encapsulated in amorphous carbon by using metal-organic framework (MOF) as the precursor and three-dimensional nickel foam (NF) as the support, which is termed as Ni2P-Co2P@C/NF. This composite demonstrates remarkable electrocatalytic activities towards both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline electrolyte (1 M KOH, pH 13.6), affording low overpotentials of 290 and 167 mV to deliver the current density of 50 mA cm−2 for OER and HER, respectively, preceding the majority of recently reported MOFs-derived TMPs. This excellent performance is considered as the results of its large catalytic surface area, concerted synergy from composited structure as well as the increased electrical conductivity.