From a toxic pollutant to a catalyst: one-pot synthesis of Fe3O4-Ni-DBP/NF for efficient overall water splitting

Abstract

Dibutyl phthalate (DBP), a ubiquitous plasticizer pollutant, poses severe risks to environmental and human health, yet its high chemical stability makes valorization highly challenging. Herein, we report a one-pot, mild, and green strategy that directly upcycles DBP as an organic ligand to construct a ferroferric oxide functional Ni-based MOF framework nanocomposite (Fe₃O₄-Ni-DBP) on nickel foam (NF), enabling the simultaneous detoxification of DBP and fabrication of a high-performance electrocatalyst. The in situ integration of Fe₃O₄ nanoparticles with Ni-DBP endows the hybrid catalyst with accelerated charge-transfer kinetics, enhanced electrical conductivity, and abundant accessible active sites, leading to remarkable bifunctional activity for overall water splitting. In an alkaline electrolyte, Fe₃O₄-Ni-DBP/NF exhibits outstanding bifunctional electrocatalytic performance, delivering low overpotentials of 233 mV for the Oxygen Evolution Reaction (OER) and 42 mV for the Hydrogen Evolution Reaction (HER) at 10 mA cm⁻², along with excellent durability over continuous operation exceeding 40 h. In situ Raman analysis reveals that the superior catalytic performance of Fe₃O₄-Ni-DBP/NF is attributed to the dynamic reconstruction of surface metal sites into active (oxy)hydroxide intermediates. This work presents an innovative strategy for the valorization of toxic plastic pollutants, thus advancing the cross-integration of environmental remediation and clean energy technologies.