Green preparation of Fe3O4 coral-like nanomaterials with outstanding magnetic and OER properties

Abstract

Abstract Developing multifunctional of a material is a good alternative for optimizing their use in many fields. In this study, a series of Fe3O4 coral-like nanomaterials with excellent magnetic and electrocatalytic oxygen evolution reaction (OER) properties were greenly prepared by a facile template-assisted dipping/adsorbing-calcining two-steps method and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy and BET techniques. Meanwhile, the effect of calcination temperature on the properties of the as-prepared samples was investigated. The results display that the magnetic and electrocatalytic OER properties of as-prepared Fe3O4 nanomaterials are affected by calcining temperature. For example, their magnetic intensity increases with increasing the temperature while the OER activity is best at 450 °C, an overpotential of 234 mV@10 mA cm−2 with a Tafel slope of 100 mV dec−1. It is believed that the excellent electrocatalytic OER property of as-prepared sample at a proper calcining temperature should give the credit to its special morphology, which endows large surface area and special pore structure/size and proper structural defect, bringing about efficient adsorption and activation and fast migration of the reactant molecules, and offering the smooth path of elctron transfer for promoting the OER activity. It is worthy mentioned that this preparation strategy is low-cost, simple, environmentally friendly, and can make full use of the wasted resources.