Greenly synthesised novel microporous ZnO/GO for adsorption of methyl orange and malachite green

ABSTRACT

This study presents a greenly synthesised novel nanocomposite composed of Zinc Oxide (ZnO) and Graphene Oxide (GO) for the adsorption of dyes from aqueous solutions. The nanocomposite was synthesised using algae thus representing a green and eco-friendly method, ensuring minimal environmental impact. The physical characterisation of zinc oxide and graphene oxide nanocomposite (ZnO/GO) was done using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FT-IR), Zeta Potential, and Particle Size Analyzer (PSA). The pore diameter of the ZnO/GO was 1.801 nm, and its total surface area was 54.062 m²/g. The nanocomposite’s adsorption performance was systematically investigated through batch adsorption experiments. With an adsorption efficiency of 296.73 mg/g and 259.74 mg/g for MO and MG, the Langmuir isotherm model outperforms the Freundlich isotherm model in terms of adsorption. The pseudo-second-order model having an R² value of 0.99 for both MO and MG, offers a more convincing explanation of adsorption than the pseudo-first-order model. The results demonstrated rapid adsorption kinetics and high adsorption capacities for both cationic and anionic dyes. Additionally, the ZnO/GO has a high reusability without significant degradation. The sustainable nature of the nanocomposite was emphasised by its efficient dye removal, reusability, and minimal secondary waste generation.

Graphical Abstract

KEYWORDS:

• Wastewater
• zinc oxide
• graphene oxide
• nanocomposite
• remediation
• dye

Acknowledgments

One of the authors Anuj Sharma is highly thankful to the All India Council for Technical Education (AICTE) for the AICTE Doctorate Fellowship (ADF).

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

All the data generated or analysed during this study are included in this article.

Supplementary data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/03067319.2024.2346198.

Additional information

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.