A novel study to effectively remove arsenite from aqueous solutions by MXene-functionalised cobalt ferrite and nickel ferrite

Arsenite is considered the most toxic heavy metal found in drinking water, and its removal is a worldwide challenge. This work demonstrates the novel application of MXene, an emerging 2D material with enhanced surface functional groups. It was functionalised with cobalt ferrite and nickel ferrite for the adsorption of As(III). The synergy of MXene provides high surface activity, magnetic behaviour, easy recovery and improved sustainability in water remediation. The hydrothermal method was chosen as a primary procedure to ensure high purity and improved sorption capacity. The samples were characterised using various analytical techniques, including X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, EDX mapping, transmission electron microscopy, and vibrating sample magnetometer. Arsenic was removed through adsorption and analysed via batch experiments. The performance of the adsorbents for As(III) removal was evaluated by examining adsorption isotherms, kinetics, thermodynamic parameters and reusability. The other toxic co-existing ions did not interfere with the adsorption capacity of the adsorbents for As(III) and were effectively removed. The highest adsorption capacity and efficiency, of 3333, 2500, 2500 µg g−1 and 91%, 89% and 83% for As(III) removal were observed for MXene functionalised with cobalt ferrite, MXene functionalised with nickel ferrite and pristine MXene, respectively.