abstract
- This work presents a study of the photoluminescent effect of Carbon Quantum Dots (CQDs) obtained from Hibiscus Sabdariffa flowers by a simple calcination method, without thermal pretreatment, processed in open-air and using precursors with a higher content of functional groups. CQDs exhibited high UV-light absorption, blue light emission, and a Quantum Yield (QY) of 22.09 % when Sudán flower was calcinated on a hot-plate. The influence of functional groups and crystalline core on the photoluminescence effect was assessed. Results showed an increase in the crystalline grade at high temperatures (450 °C), as well as a reduction in functional groups. Both aspects demonstrated their relevance on photoluminescent emission. © 2025 Elsevier B.V.