Hydrothermal synthesis of carbon quantum dots from Citrus reticulata and Eriobotrya japonica: Characterization and photothermal evaluation

This study introduces a hydrothermal approach to synthesizing carbon quantum dots utilizing Citrus reticulata and Eriobotrya japonica peels as environmentally friendly precursors. The photoluminescence and light-to-heat conversion capabilities of the carbon quantum dots were evaluated. Transmission electron microscopy analysis confirmed carbon quantum dots with sizes ranging from 1 to 4 nm for both carbon sources. Ultraviolet–Visible spectroscopy revealed typical absorption bands, while X-ray diffraction indicated a hexagonal crystalline structure. Fourier-transform infrared spectroscopy detected oxygen functional groups on the carbon quantum dots surfaces. Thermograms demonstrated an approximately 8 °C increase in temperature for both carbon sources, suggesting potential applications in areas such as drug delivery and detection.