Photocatalytic degradation of methyl green dye by nitrogen-doped carbon quantum dots: Optimisation study by Taguchi approach

Abstract

Empty fruit bunches (EFB) biomass can be a sustainable source for the fabrication of nitrogen-doped carbon quantum dots (NCQDs) through hydrothermal treatment. However, the performance and stability of NCQDs produced for methyl green (MG) photocatalysis are yet to be evaluated. This study discusses the photodegradation of MG using NCQDs produced from EFB through the Taguchi approach. At room temperature and an MG dye solution of pH 7, functionalised NCQDs performed as effective photocatalysts in degrading 99% of MG dye under UV-light irradiation (302 nm) within 20 min. NCQDs fabricated from EFB showed outstanding stability and reactivity after 12 months of storage duration. NCQDs could be reused in photocatalysis for at least five cycles while maintaining their photo-degradability of MG above 70%. NCQDs fabricated from EFB biomass show great potential in treating wastewater contaminated with organic dyes.