Smart chitosan Schiff base ferrite: a dual-action visible light photocatalyst for dye degradation and antimicrobial defense

Abstract

This study presents the novel fabrication of a new visible-light-driven SBXIII@NiFe photocatalytic material, which was then used to photodegrade two key exemplar water pollutants, methyl orange and rhodamine-B. The structure of the material, chemistry, and optical characteristics of the SBXIII@NiFe nanocomposites were thoroughly examined using various characterization techniques. Scanning electron microscopy reveals that SBXIII molecules are incorporated into the NiFe particles. Spectrophotometry was used to quantify the rate of decolorization from the remaining quantities. Similar studies were carried out with different pH (2–12), catalyst quantity (0.25–2.0 g L⁻¹), and electrolyte concentration (0.1–2 mol L⁻¹). The experiments showed that the SBXIII@NiFe photocatalyst resulted in the highest decolorization (more than 90%) of dyes, with MO degrading the most at pH 4 and RH-B at pH 9. Among the synthesized NiFe and its SBXIII@NiFe composite, the latter exhibits higher photocatalytic efficiency. This finding was ascribed to the synergistic impact of SBXIII and NiFe, with SBXIII acting as an electron trap site, reducing electron–hole recombination and inducing visible light absorption. The active entity trapping studies identify (OH˙) and (O₂˙⁻) radicals as the significant reactive agents involved in the oxidative photodegradation of dye contaminants. Based on these findings, a potential photocatalytic pathway has been postulated. Furthermore, the engineered photocatalyst was tested for antibacterial efficacy towards Gram-positive (S. aureus) and Gram-negative (P. vulgaris) bacteria. The inclusion of chitosan, as well as the synergistic actions of ferrite and anthrone, increased the antibacterial activity significantly.