Green construction of metal- and additive-free citrus peel-derived carbon dot/g-C3N4 photocatalysts for the high-performance photocatalytic decomposition of sunset yellow

In this study, novel, metal-free, CP-derived CDs/g-C3N4 nanocomposites (CDCNs) were created by introducing citrus peel-derived carbon dots (CP-derived CDs) into graphite carbon nitride (g-C3N4) by a green hydrothermal method. The CDCNs were revealed to have superior photoelectrochemical properties relative to pristine g-C3N4 for the photocatalytic degradation of the food dye sunset yellow (SY) under visible light. For SY decomposition, the recommended catalyst contributed almost 96.3% to the photodegradation rate after 60 min of irradiation, showing satisfactory reusability, structural stability and biocompatibility. Moreover, a mechanism for enhanced photocatalytic SY degradation was proposed according to band analysis, free radical trapping and electron paramagnetic resonance (EPR) results. A possible pathway for SY photodegradation was also predicted from UV-visible (UV-Vis) spectroscopy and high-performance liquid chromatography (HPLC) results. The constructed nonmetallic nanophotocatalysts afford a novel route for the elimination of harmful dyes and for the resource conversion of citrus peels.

Automated summary

Novel metal-free CP-derived CDs/g-C3N4 nanocomposites (CDCNs) were synthesized by introducing citrus peel-derived carbon dots (CP-derived CDs) into graphite carbon nitride (g-C3N4) using a green hydrothermal method. The CDCNs exhibited superior photoelectrochemical properties compared to pristine g-C3N4 for the photocatalytic degradation of sunset yellow (SY) dye under visible light. After 60 minutes of irradiation, the recommended catalyst contributed to approximately 96.3% of the photodegradation rate of SY, demonstrating satisfactory reusability, structural stability, and biocompatibility. A mechanism for enhanced photocatalytic SY degradation was proposed based on band analysis, free radical trapping, and electron paramagnetic resonance (EPR) results. UV-visible (UV-Vis) spectroscopy and high-performance liquid chromatography (HPLC) results provided insights into the possible pathway for SY photodegradation. The developed nonmetallic nanophotocatalysts offer a novel approach for the removal of harmful dyes and the resource conversion of citrus peels.