Synthesis of adsorption cum photocatalytic nature of polyaniline-ZnO/chitosan composite for removal of textile dyes

Abstract

A B S T R A C TThe polyaniline-ZnO/chitosan (PZO/chitosan) nanocomposite synthesized using aniline, ZnCl 2 and chitosan through precipitation-oxidation method and the synthesized composite was extensively characterized by Fourier transform infrared spectra, UV-vis spectroscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffraction measurements which indicated that the successful formation of ZO nano-rod present inside the chitosan-polyaniline composite. The adsorption and photocatalytic properties of the prepared samples were evaluated by measuring the decrease in concentration of reactive orange after adsorption in the dark and photocatalytic reaction under UV irradiation, respectively. The influences of initial dye concentration, catalyst amount and pH of the reaction solution on reactive orange decolorization were investigated. It was found that the rate of composite/dye interaction was enhanced with the increased load of composite and retarded with the increase in initial dye concentration and pH. Compared with reactive orange, methylene blue as a target pollutant, the adsorption-photocatalytic activities of the resulting composites under different light sources (dark, sunshade, UV and direct sunlight) were also investigated. Results indicates that the maximum color removal were 96% and 88.5% for reactive orange and methylene blue with the corresponding dye concentration 50 mg L −1 , PZO/chitosan amount of 0.3 g L −1 and neutral pH in 120 min of sunlight exposure respectively. Based on the results, we conclude that PZO/chitosan nanocomposite having both the advantages of photodegradation-adsorption process in the abatement of various wastewater pollutants.

Review of the Advancements on Polymer/Metal Oxide Hybrid Nanocomposite‐Based Adsorption Assisted Photocatalytic Materials for Dye Removal

“…Chitosan cannot increase photocatalytic degradation reaction directly; rather aids the adsorption of substrates to the surface where degradation occurs. [51,[97][98][99] In CuO and Co 3 O 4 composites containing chitosan/PANI, the same trend was observed. However, the functions of the PANI and metal oxides are reversed, with the PANI acting as an electron-hole stabilizer and the metal oxides acting as a sensitizer.…”

“…Hence, the composite catalyst's photocatalytic degradation of cationic and anionic dyes is enhanced relative to the individual catalyst. [97][98][99][100] The possible reaction mechanism is given below.…”

Preparation, characterization and antibacterial mechanism of the chitosan coatings modified by Ag/ZnO microspheres

“…The less prominent peaks at 2362 and 2341 cm −1 are attributed to CO 2 molecular in the air 27 . The peak at 1408 cm −1 is produced by associative OH, and absorption peaks at 1046 and 911 cm −1 are produced by O‐Zn‐OH, suggesting the water of hydration with ZnO 55–57 . The significant peak at 450 cm −1 is the oxygen sublattice vibrations in ZnO 58 .…”

“…27 The peak at 1408 cm −1 is produced by associative O H, and absorption peaks at 1046 and 911 cm −1 are produced by O-Zn-OH, suggesting the water of hydration with ZnO. [55][56][57] The significant peak at 450 cm −1 is the oxygen sublattice vibrations in ZnO. 58 According to Fig.…”

Enhancing the Performance and Recyclability of Polyaniline/TiO2 Hybrid Nanocomposite by Immobilizing with Zein/Hydroxyethyl cellulose Composites for Removal of Anionic dyes

“…Similarly, a dramatic decrease in higher basic pH was caused by the generation of negatively charged groups due to deprotonation of carboxylic groups on glutamate. This creates strong electrostatic interaction with anionic dyes, which caused a decrease in the reaction [60]. Different amino acid groups were disclosed in a mildly alkaline solution, and thus, catalytic degradation was enhanced.…”