One-pot hydrothermal synthesis of a carbon quantum dot/CaFe₂O₄ hybrid nanocomposite for carcinogenic Congo red dye degradation

Semiconductor materials show a restricted degradation response to organic pollutants due to limited photocatalytic activity under visible light. Therefore, researchers have devoted much attention to novel and effective nanocomposite materials. For the first time, herein, a novel nano-sized semiconductor calcium ferrite modified by carbon quantum dots (CaFe2O4/CQDs) photocatalyst is fabricated via simple hydrothermal treatment for the degradation of aromatic dye using a visible light source. The crystalline nature, structure, morphology, and optical parameters of each of the synthesized materials were investigated using X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and UV-visible spectroscopy. The nanocomposite exhibits excellent photocatalytic performance (90% degradation) against Congo red (CR) dye. In addition, a mechanism for CaFe2O4/CQDs improving photocatalytic performance has been proposed. The CQDs in the CaFe2O4/CQD nanocomposite are considered to act as an electron pool and transporter, as well as a strong energy transfer material, during photocatalysis. CaFe2O4/CQDs appear to be a promising and cost-effective nanocomposite for dye-contaminated water purification, according to the findings of this study.