MXene-Enhanced Metal–Organic Framework-Derived CoP Nanocomposites as Highly Efficient Trifunctional Electrocatalysts for OER, HER, and ORR

Abstract

Developing robust active electrocatalysts from readily available earth-abundant elements for oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and oxygen reduction reaction (ORR) remains an unresolved challenge. Herein, Ti₃C₂T_x MXene-containing metal–organic framework-derived CoP nanocomposite electrocatalysts are successfully prepared by phosphidation of in situ-produced ZIF-67/MXene composite precursor at various heat treatment temperatures. The obtained nanocomposite catalysts are characterized by X-ray diffraction, Brunauer–Emmett–Teller, X-ray photoelectron spectroscopy, field emission-scanning electron microscope/energy dispersive X-ray spectroscopy (EDS), and high-resolution transmission electron microscopy/EDS. In the produced composites, Ti₃C₂T_x MXene functions as a supportive substrate to facilitate mass transfer, as well as ion transport, and to improve electrical conductivity. Moreover, the introduction of MXene into the heterostructured CoP@C/Ti₃C₂T_x enables it to expose and provide extra active sites for electrochemical reactions. The as-prepared CoP@C/MXene-360 (abbreviated as CPMX-360) nanocomposite is a promising trifunctional electrocatalyst toward OER, HER, and ORR. CPMX-360 exhibits excellent electrocatalytic activity with an overpotential of 235 mV at 10 mA cm⁻² in OER, an overpotential of 220 mV at −10 mA cm⁻² in HER, and an E_onset and E_1/2 of 0.82 and 0.74 V in ORR, respectively. This research provides a viable method to develop nonprecious trifunctional electrocatalyst via phosphidation of metal–organic framework and MXene with excellent performance for OER, HER, and ORR.