Fluorine-doped cobalt ferrite integrated into 2D MXene with extended solar spectrum response and boosted charge separation for the removal of recalcitrant organic pollutants

Abstract

In investigating sustainable methodologies for removing recalcitrant organic pollutants from wastewater, visible-light-responsive photocatalysis has drawn considerable interest. Therefore, intentionally engineered photocatalysts with enhanced solar-light-absorption capacity and boosted charge carrier’s separation are highly demanded. In the present attempt, pure cobalt ferrite (CoFe₂O₄) and its fluorine-doped counterpart (F-CoFe₂O₄) were fabricated via co-precipitation. The fluorine-doped material was integrated into the 2D MXene to design the composite (F-CoFe₂O₄@MXene) by the ultrasonication method. The structure, surface morphology, chemical composition, and optical properties of the as-prepared catalysts were characterized by various techniques, including powder XRD, FTIR, SEM, EDS, UV–vis absorption, and photoluminescence spectroscopy. The photocatalytic potential was estimated by degrading crystal violet (CV) dye and benzoic acid (BA), which were selected as model pollutants. The composite material showcases significantly enhanced catalytic efficiency relative to the pure and doped materials. Under solar light exposure for 140 min, 91 % (0.0138 min⁻¹) and 87 % (0.0133 min⁻¹) of CV and BA degradation were achieved, respectively. The remarkable catalytic potential of the composite material corresponds to the fluorine doping and integration to the 2D MXene, which has enhanced its visible-light absorption and lowered the rapid recombination rate of the separated charges (e^-/h⁺). Systematic studies, including reaction kinetics, dominating catalytic species in photodegradation, and stability of the catalyst, were followed through to disclose the photocatalytic potential of the designed F-CoFe₂O₄@MXene. Furthermore, the real-time applicability of the catalyst has been explored.