Amine‐Functionalized and Amine‐Functionalized with Carbon Dots (C‐Dots) Sodium Titanate Nanotubes: Synthesis, Characterization, and Degradation of Tetracycline

ABSTRACT This study investigated how chemical modifications applied to sodium titanate nanotubes (NaTiNTs), involving surface functionalization with amine groups (NaTiNTs‐2NH) and subsequent modification with carbon dots (C‐Dots) obtained during the hydrothermal synthesis process—using the mesocarp of babassu coconut as one of the precursor components to produce the C‐Dots and, ultimately, the NF‐C‐Dots sample, influence the optical, vibrational, and photocatalytic properties of these modified materials. Structural and morphological analyses confirmed that the integrity of the NaTiNTs structure was preserved after functionalization and incorporation of C‐Dots. Optical characterizations revealed a broadening of the light absorption range, a reduction in band gap energy, and an increase in Urbach energy, attributed to greater particle aggregation. Photocatalytic degradation tests of tetracycline (TC) showed that the sample modified with C‐Dots (NF‐C‐Dots) did not outperform its counterpart without C‐Dots. The NaTiNTs‐2NH sample exhibited the highest degradation efficiency, removing approximately 77.23% of TC at 0.25 g·L −1 , surpassing both the pure titanate and the C‐Dot‐modified sample.These results underscore the significance of functionalization with amine groups in enhancing the optical and vibrational properties, as well as optimizing the photocatalytic activity of titanate‐based nanomaterials.