Remediation of Toxic Dye Pollutants by Using Graphene‐Based Adsorbents

• Published in: ChemistrySelect (Weinheim) Vol. 5; no. 27; pp. 8062 - 8073
• Main Authors: Lokhande, Kshama D., Pethsangave, Dattatray A., Kulal, Dnyaneshwar K., Some, Surajit
• Format: Journal Article
• Language: English
• Published: 23.07.2020
• Subjects: adsorption; adsorption isotherm; Graphene oxide; methylene blue; recyclability
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.202002130

In this article, we report a facile strategy for the synthesis of G@SiO2‐AR by using silica nanoparticles, which are coated with graphene and alkyd resin. During the synthesis of G@SiO2‐AR, the silica particles have been prepared in situ by hydrolysis of tetraethyl ortho silicate (TEOS). The G@SiO2‐AR has been employed to remove the methylene blue (MB) from aqueous solution. G@SiO2‐AR has a strong affinity to adsorb MB as MB is a cationic dye and it is strongly attracted by anions induced by deprotonation of acid functionality on GO. The detailed adsorption characteristics of G@SiO2‐AR, such as adsorption kinetic and adsorption isotherm has been investigated. The efficiency of dye adsorption on a G@SiO2‐AR has been investigated under various parameters such as contact time, temperature, and pH. The adsorption experiment has been carried out by keeping the constant adsorbent dose in 50 mL of 50 ppm dye solution with varying time intervals such as 5, 10, 15, 20 and 25 min at room temperature. We got better results at 20 min and the dye removal efficiency of G@SiO2‐AR and SiO2@AR is 95.08 % and 87.32 % respectively at room temperature. Also, we carried out the same experiment at different temperatures ranging from 298, 308 and 318 K, out of which the highest adsorption efficiency of above‐mentioned adsorbents has been observed at 318 K up to 99.72 % and 93.16 % respectively. Kinetic data has been shown that the adsorption phenomenon follows the pseudo‐second order kinetic model, while adsorption isotherm follows the Langmuir adsorption isotherm. In this work, we had developed a simple process to synthesize silica coated graphene and alkyd resin (G@SiO2‐AR), while same material had prepared without GO (SiO2@AR) for effective dye removal. The adsorption capacities of G@SiO2‐AR and SiO2@AR are 831.76 and 384.61 mg g−1 respectively. Kinetic data has been shown that the adsorption phenomenon follows the pseudo‐second order kinetic model, while adsorption isotherm follows the Langmuir adsorption isotherm.