Synthesis of graphene quantum dots from rice husk for water treatment applications

Johari, Faiz Haikal and Makhsin, Siti Rabizah and Mohd Zaki, Syazwani and Roslan, Azib Haiman and Siddique, Beenish (2026) Synthesis of graphene quantum dots from rice husk for water treatment applications. Journal of Mechanical Engineering, 23 (2). pp. 135-150. ISSN 1823-5514 E-ISSN 2550-164X

PDF - Published Version Restricted to Repository staff only Download (965kB) | Request a copy

Abstract

This study aims to develop a sustainable method for synthesizing graphene quantum dots (GQDs) from biomass waste for water treatment applications. Rice husk, a carbon-rich waste material, was used as a precursor for GQDs synthesis via a simple boiling method, providing a sustainable and cost-effective approach. The optimal GQDs sample (2.5% w/v) was prepared from 5 g of rice husk and 200 mL of deionized water, exhibiting greenish fluorescence under UV light, indicating successful GQD formation. The synthesized GQDs were characterized by ultraviolet–visible (UV–Vis), Fourier-transform infrared (FTIR) and fluorescence spectroscopy, as well as zeta potential analysis. The 2.5% w/v filtered GQDs showed low absorption beyond 230 nm in the UV region, a zeta potential of −20.6 ± 1.0 mV indicating good colloidal stability, and the presence of oxygen-containing functional groups that enhance adsorption capability, as confirmed by FTIR analysis. The adsorption performance of GQDs was evaluated using methylene blue (an organic dye) and copper ions (a heavy metal). The electrical conductivity (EC) of the copper sulphate (CuSO₄) solution decreased by 54.2%, demonstrating significant removal of copper ions. In contrast, the EC of the methylene blue solution increased slightly by 21.5%, possibly due to the release of smaller ionic species during degradation or interactions between GQDs and dye molecules. In summary, this study presents an eco-friendly approach for converting biomass waste into functional nanomaterials for water purification, contributing to sustainable waste management and clean water initiatives aligned with the United Nations Sustainable Development Goals (SDGs).

Item Type:	Article (Journal)
Subjects:	T Technology > T Technology (General) T Technology > TJ Mechanical engineering and machinery > TJ807 Renewable energy sources
Kulliyyahs/Centres/Divisions/Institutes (Can select more than one option. Press CONTROL button):	Kulliyyah of Engineering > Department of Manufacturing and Materials Engineering
Depositing User:	Dr Syazwani Mohd Zaki
Date Deposited:	22 Jul 2026 22:21
Last Update:	22 Jul 2026 22:21
Queue Number:	2026-07-Q4168
URI:	http://irep.iium.edu.my/id/eprint/130066

Actions (login required)

View Item