Synthesis and characterization of red emissive carbon quantum dots for MB degradation

Abstract

In this study, red-emissive carbon quantum dots (R-CQDs) were synthesized using a simple, one-step solvothermal method with 1,3-naphthalenediol as the carbon source. The synthesized R-CQDs were thoroughly characterized in terms of morphology, crystallinity, functional groups, optical, and photocatalytic properties. The R-CQDs exhibited an average particle size of 5 nm, with functional groups aiding in their uniform dispersion in water. Raman spectra revealed the presence of both D and G bands, indicating successful construction of a sp² core and sp³ hybridized matrix. The R-CQDs showed strong absorption at 512 nm and high emission intensity at 610 nm. Additionally, the R-CQDs demonstrated exceptional photocatalytic performance, achieving 96 % methylene blue degradation in 180 min, with a calculated rate constant of 0.0167 min⁻¹. Their stability across different pH levels further underscores their potential as efficient photocatalysts in a variety of environmental applications.