Construction of multiple heterogeneous interfaces and oxygen evolution reaction of hollow CoFe bimetallic phosphides derived from MOF template

Abstract

Rational design of electrocatalysts is the key to achieving sustainable oxygen evolution reaction (OER). The conjugation of metal organic frameworks (MOFs) with different multicomponent materials to precisely construct heterostructures is fascinating but remains a significant challenge due to different interface energies and nucleation kinetics. In this work, hollow multilayer heterogeneous catalyst (CoFeP/CoFeP/NP-C) was constructed using a rigid template sacrifice approach and an ion exchange strategy. By cleverly combining iron-based MOFs (MIL-88A, sacrifice template) nanorods, layered dihydroxides (LDH) nanosheets, and Prussian blue (PB) nancubes to form rich heterojunction and bimetallic phosphide catalysts, and by tuning the reaction kinetics and electron transfer capacities to enrich the active sites, ultimately promoting the intrinsic activity of the catalyst towards OER. Simultaneously, the co-doping of nitrogen and phosphorus in the heterostructure helped to adjust the electronic structure of the heterogeneous catalyst and the conductivity of the matrix, promoting the adsorption and desorption of OER intermediates on the catalyst surface. This work provides a new strategy for designing efficient and stable bimetallic phosphide electrocatalysts.