Facile One-Step Hydrothermal Synthesis Of Alpha-Fe2o3/G-C3n4 Composites For The Synergistic Adsorption And Photodegradation Of Dyes

With the expansion of industrialization, dye pollution has become a significant hazard to humans and aquatic ecosystems. In this study, alpha-Fe2O3/g-C3N4-R (where R is the relative percentage of alpha-Fe2O3) composites were fabricated by a one-step method. The as-prepared alpha-Fe2O3/g-C3N4-0.5 composites showed excellent adsorption capacities for methyl orange (MO, 69.91 mg g(-1)) and methylene blue (MB, 29.46 mg g(-1)), surpassing those of g-C3N4 and many other materials. Moreover, the ionic strength and initial pH influenced the adsorption process. Relatively, the adsorption isotherms best fitted the Freundlich model, and the pseudo-second-order kinetic model could accurately describe the kinetics for the adsorption of MO and MB by alpha-Fe2O3/g-C3N4-0.5. Electrostatic interaction and pi-pi electron donor-acceptor interaction were the major mechanisms for MO/MB adsorption. In addition, the photocatalytic experiment results showed that more than 79% of the added MO/MB was removed within 150 min. The experimental results of free-radical capture revealed that holes (h(+)) were the major reaction species for the photodegradation of MO, whereas MB was reduced by the synergistic effect of hydroxyl radicals (center dot OH) and holes (h(+)). This study suggests that the alpha-Fe2O3/g-C3N4 composites have an application potential for the removal of dyes from wastewater.