Tailoring the photocatalytic activity of novel magnetically separable ZnFe12O19-chitosan bionanocomposites: A green preparation, structural characterization and comparative study

Abstract

Nowadays, the evaluation of nano-catalyts and photocatalytic technology for inactivating environmental pollution is identified as a priority. Although a series of semiconductor nanomaterials have been proven for this aim, suppression of charge carrier recombination and the absorption of solar light are still challenging. In this study, a novel visible-light-responsive bionanocomposite of ZnFe12O19-chitosan (ZF-C) is designed by a facile two-step approach. The utilization of two natural stabilizer and capping agents including turnip and carrot juices is developed to adopt nucleation and growth mechanism of as-fabricated crystals. In addition, benefiting from green templates, various quantities of these precursors show a strong impact on the construction of products in terms of structure and shape. The physic-chemical results confirmed creation of uniform ZF nanoparticles employing 20 mL of turnip juices. The band gap energy of ZF-C nanocomposites was found to be 1.55 eV, offering highly light absorption property in visible area. Moreover, the optimum photocatalyst had a specific surface area of 3.37 m2 g −1. This research encompasses the first insights of photocatalytic efficiencies of ZF and [ZF-Cx] (x: 5.0%, 10.0% and 15.0%) nanocomposites toward five toxic dyes such as methyl violet (MV), erythrosine (EY), methylene blue (MB), methyl orange (MO), and rhodamine B (RhB) under visible light. As a proof-of-concept, the nanocomposites with 10.0% of chitosan matrix could exhibit higher photocatalyst performance about 94.12% EY removal after 120 min, which is 1.15 times better than that of pristine ZF nanostructures. Based on active species trapping experiments, a possible photodegradation pathway of EY dye over the [ZF-C10] nanocomposites has been reported. These findings describes a revolutionary way for selecting [ZF-C10] nanostructure as eco-friendly and magnetically recyclable photocatalysts in dye-containing effluents.