Facile synthesis of recoverable superparamagnetic AgFeO₂@Polypyrrole/SiO₂ nanocomposite as an excellent catalyst for reduction and oxidation of different dyes in wastewater

Abstract

Fabrication of a triple-component nanocomposite system having a unique design and unusual property combinations offers a special chance to take advantage of all components and overcome the limitations of mono nanoparticles (NPs). Novel superparamagnetic AgFeO 2 @polypyrrole/SiO 2 (AgFeO 2 @PPy/SiO 2 ) triple-component nanocomposite was synthesized in facile three-step method using (i) coprecipitation, (ii) in situ chemical oxidative polymerization, and (iii) Stöber process. The structure and morphology of the nanocomposite were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). The triple nanocomposite has a drastic catalytic effect as compared with AgFeO 2 @PPy core-shell NPs and AgFeO 2 NPs. The rate constant of chromotrope 2R reduction followed the order: AgFeO 2 @PPy/SiO 2 (0.9209 min À1 ) > AgFeO 2 @PPy (0.2274 min À1 ) > AgFeO 2 (0.1365 min À1 ). AgFeO 2 @PPy/SiO 2 exhibited high catalytic recyclable performance towards the degradation of different kinds of dyes either by reduction (chromotrope 2R, tartrazine, and methylene blue) or by oxidation (methylene blue, aniline blue, and methyl violet 2B) from aqueous solution. The degradation percentage for the reduced dyes was 99.38%, 98.64%, and 98.17% and for the oxidized dyes was 75.84%, 99.34%, and 91.79%, respectively. Batch mode catalytic study was conducted with the nanocomposite to determine the maximum removal of tartrazine and aniline blue under different operational parameters was 99.5% and 99.34%, respectively. The recovery and reusability of the AgFeO 2 @PPy/SiO 2 nanocomposite were studied using the reduction of tartrazine and the oxidation of aniline blue. Thirteen consecutive recovery reaction cycles were performed for the reduction process and nine cycles for the oxidation reaction. All the reactions revealed high stability and constant efficiency of the catalyst. The maximum percentages were 99.5% for the reduction and 99.34% for the oxidation of dyes. These values decreased through the cycles to 76.35% and 79.70%

Facile synthesis of magnetically separable copper ferrite infused sulfonated graphene oxide nanocomposite with antimicrobial evaluation and photocatalytic performance under visible light

“…The degrading efficiency of the current study was contrasted with some of the previously published photocatalysts to determine the efficacy of our photocatalyst, [45][46][47][48][49][50] and the findings are summarized in Table 1. When compared with the other most frequently published works, our catalyst demonstrated greater dye degradation efficacy for large concentrations with lesser dosage of photocatalyst in lesser duration as well as in milder circumstances under visible light.…”

Highly efficient and recyclable novel spindles Fe2O3@SiO2/In2O3 nanomagnetic catalyst designed for green synthesis of azomethine compounds

“…Thus, the coated samples can easily be separated from the reaction mixture with an external magnet. Since the units of the magnetization are reported per gram of material, such a decrease in Ms would reflect a smaller percentage of net magnetic material per gram of the overall sample [40,41].…”