Hierarchical assembly of NiFe-PB-derived bimetallic phosphides on 3D Ti3C2 MXene ribbon networks for efficient oxygen evolution

Abstract

The development of MXene-based heterostructures for electrocatalysis has garnered significant attention owing to their potential as high-performance catalysts that play a pivotal role in hydrogen energy. Herein, we present a multistep strategy for the synthesis of a Ti₃C₂ MXene ribbon/NiFeP_x @graphitic N-doped carbon (NC) heterostructure that enables the formation of three-dimensional (3D) Ti₃C₂ MXene ribbon networks and bimetallic phosphide nanoarrays. With the assistance of HF etching and KOH shearing, the MXene sheets were successfully transformed into 3D MXene networks with interlaced MXene ribbons. Notably, a hydrothermal method, ion exchange route, and phosphorization process were used to anchor NiFeP_x@NC nanocubes derived from Ni(OH)₂/NiFe-based Prussian blue (NiFe-PB) onto the MXene ribbon network. The resulting MXene ribbon/NiFeP_x@NC heterostructure demonstrated enhanced oxygen evolution reaction (OER) activity, characterized by a low overpotential (164 mV at a current density of 10 mA cm⁻²) and a low Tafel slope (45 mV dec⁻¹). At the same time, the MXene ribbons/NiFeP_x@NC heterostructure exhibited outstanding long-term stability, with a 12 mV potential decay after 5000 cyclic voltammetry (CV) cycles. This study provides a robust pathway for the design of efficient MXene-based heterostructured electrocatalysts for water splitting.