Photocatalytic degradation of alizarin yellow in aqueous medium and real samples using chitosan conjugated tin magnetic nanocomposites

Polymer metal oxide composites find numerous applications for the decontamination of various pollutants. In the present study, chitosan conjugated tin magnetic nanocomposites (Sn-CCMN) was synthesized via a modified co-precipitation method. The synthesized material was characterized using FT-IR, XRD, SEM and EDX spectroscopic techniques. The FT-IR data confirmed the successful synthesis of the material, whereas the XRD analysis showed the amorphous nature of Sn-CCMN. The SEM results declared the irregular shape with porous surfaces and almost uniform particle size of Sn-CMMN with an average grain size of 84 ± 3 nm and desired elemental composition as confirm from the EXD spectral data. It was concluded that the Sn–Fe magnetic nanoparticles were well-embedded in the chitosan polymer matrix. The band gap energy (E_g) and point of zero charge (PZC) of the synthesized material were also determined and found to be 3.16 eV and 7.75, respectively. The photocatalytic potential of the synthesized Sn-CCMN was investigated under UV-light irradiation (254 nm and 15 W) in the aqueous medium using alizarin yellow (ALY) as a model environmental pollutant. The effect of various operating parameters such as irradiation time, pH, catalyst dose and concentration of dye was studied and at the optimal conditions, Sn-CCMN was applied for the photocatalytic degradation of ALY in the real samples. The synthesized material showed excellent photocatalytic property with reaction rate constant (k) and rate of reaction of 0.0039 min⁻¹ and 0.042 ppm/min, respectively. The synthesized Sn-CCMN was recycled and reused, maintaining its structural characteristics and excellent photocatalytic activity for four consecutive batches.