الفهرس 
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Abstract
The indium (III) oxide nanoparticles were successfully prepared via two procedures including sol-gel and hydrothermal methods. It was modified by incorporating with polymeric matrix to produce polymeric nanocomposites. In this study, it was individually modified with polyaniline (PANI) and carboxymethyl cellulose (CMC). The developed nanocomposites were utilized as an excellent adsorbent for removing organic pollutants such as Acid blue 25 (AB 25) dye and 4-nitrophenol (4-NP) from aqueous solutions. Various characterization techniques including FT-IR, XRD, TGA, SEM, EDX, TEM, BET, and Zeta potential analysis were carefully used to verify that the nanocomposite was successfully synthesized. The first nanocomposite In2O3/PANI has been fabricated to remove the noxious anionic AB 25 dye by adsorption. The developed adsorbent features a porous structure with an average particle size of 58.43 nm. The results revealed that only 7 mg of the nanocomposite can efficiently remove 95.5 % of AB 25 within 90 min. In addition, the AB 25 adsorption data were accurately matched to the Langmuir and Toth isotherm models with a maximum adsorption capacity of 253.36 mg/g. The adsorption results also kinetically followed the pseudo-second-order model. Thermodynamically, the adsorption AB 25 was spontaneous and endothermic. Notably, the nanocomposite displayed auspicious adsorption selectivity towards the anionic AB 25 compared to the cationic dye methylene blue (MB). Interestingly, the as-fabricated In2O3/PANI nanocomposite retained satisfactory adsorption characteristics after five consecutive cycles with a maximal removal percentage exceeding 83 %, suggesting it is a viable and effective option for eliminating dangerous anionic dyes from aquatic environments. The second nanocomposite based on polymeric matrix of CMC incorporated In2O3 nanoparticles was simply prepared and applied as efficient adsorbent for the elimination of 4-nitrophenol (4-NP) from aqueous solutions. The results revealed that only 3 mg of the nanocomposite can efficiently remove 95.4 % of 4-NP within 40 min. In order to investigate the mechanism of 4-NP adsorption, several kinetic models including pseudo-first-order, pseudo-second-order, and intraparticle kinetic model was applied. The equilibrium data was analyzed using adsorption isotherm models such as Langmuir, Freundlich, Sips, D-R, and Toth models. It was found that the experimental data of the adsorption studies followed the pseudo-first-order kinetic model and were more fitted to Langmuir, Sips, and Toth isotherm with a maximum adsorption capacity of 1098.56 mg g-1. Moreover, the thermodynamic results exposed that the adsorption process was an endothermic process. Besides, the developed adsorbent was able to use up to seven repeated cycles with slightly decreasing in its adsorption performance. The results indicate that the In2O3 @ CMC nanocomposite microbeads could be potentially applied as an efficient and recyclable adsorbent for the adsorptive removal of 4-NP from aqueous solutions.