Revealing the Effect of MnO2, Activated Carbon and MnO2/Activated Carbon on Chitosan Polymer Host Fabricated Co NPs: Antibacterial Performance and Degradation of Organic Compounds

Abstract

MnO2 and MnO2 blended with 1 and 2 weight percent of activated carbon (AC), MnO2/AC1 and MnO2/AC2 were synthesized through the sol–gel method. The pure chitosan (CS) films were cast in the form of films. Similarly, 5 weight% of each MnO2, AC, MnO2/AC1 and MnO2/AC2 was intermingled with the CS to produce different films, such as CS-AC, CS-MnO2, CS-MnO2/AC1 and CS-MnO2/AC2. Zero-valent Co NPs were then supported on these films through the chemical reduction method and expressed as CS@Co, CS-AC@Co, CS-MnO2@Co, CS-MnO2/AC1@Co and CS-MnO2/AC2@Co NPs. All the catalysts were characterized by field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS) and X-ray diffraction (XRD) techniques. The synthesized catalysts were used as a dip catalyst against the hydrogenation of 4-nitrophenol (4NP), and for the degradation of methyl orange (MO) and Congo red (CR) dyes. The kapp and R2 values were deduced from pseudo-first-order kinetics for 4NP and MO and zero-order kinetics for CR dye. The kapp values of CS-AC@Co and CS-MnO2/AC1@Co NPs for 4NP hydrogenation were higher than those for any other member of the series, at 1.14 10−1 and 1.56 10−1 min−1 respectively. Similarly, the rate of CR degradation was highest with CS-AC@Co. The R2 values for 4NP, MO and CR dyes were above 0.9, which indicated that the application of pseudo-first- and zero-order models were appropriate for this study. Furthermore, the antibacterial activity of all the catalysts was evaluated against Pseudomonas aeruginosa and Escherichia coli. The CS-AC@Co NPs exhibited the highest zone of inhibition compared to other catalysts against P. aeruginosa, while all the catalysts were inactive against E. coli. This study reveals that the catalyst can be used for the degradation of other pollutants and for microbial inhibition.

Green Synthesis of Withania coagulans Extract-Mediated Zinc Oxide Nanoparticles as Photocatalysts and Biological Agents

“…It is mostly used as a dyeing reagent in the cell fluorescence, in the study of water pollution used as a tracing agent, and as a colorant in dyeing fabrics, glass, leather, herbicide, and sprays. RhB has toxic effects on health, if ingested . Its chronic carcinogenicity and neurotoxicity have been proven experimentally.…”

“… 40 Various contaminants such as biodegradable dump waste, heavy metals, dyes, carcinogenic chemicals, and pharmaceutical products are discharged into water bodies. Dye industries discharged the waste effluents directly into water bodies without any proper treatment, 42 which are harmful to the aquatic system, block the photosynthetic activity of plants, and disturb the natural equilibrium process by aquatic diversity reduction. The textile dye RhB 9-(2-carboxyphenyl)-3,6-bis(diethylamino)xanthylium chloride is used as a colorant in drug and cosmetic preparations.…”

“…RhB has toxic effects on health, if ingested. 42 Its chronic carcinogenicity and neurotoxicity have been proven experimentally. Thus, due to their toxic health effects, the development of a new method for the degradation of RhB is of great significance.…”

Preparation of cellulose-based composite hydrogels for the removal of methylene blue

“…4,5 It is estimated that water-related diseases claim the lives of more than 5 million people a year, which is why in recent decades various water purification techniques have been used, including adsorption, filtration of membrane, electrochemical oxidation processes, and biological methods. 6,7 Among the many dye removal techniques, adsorption is the technique that gives the best results and can be used to remove different types of dyes. 8 (cation-polymer), (ii) hydrophobic interaction (polymer-polymer), and (iii) covalent crosslinking.…”