Structural, Optical, and Vibrational Properties of Cerium Tungstate–Titanate Nanocomposite for Tetracycline Degradation

In this study, we report on the structural, electronic, and vibrational properties of the sodium titanate nanotubes (NaTiNTs) modified with cerium tungstate (CeW), which were synthesized via a single-step hydrothermal procedure, resulting in the nanocomposite (TiNTs@CeW). Structural and spectroscopic characterizations confirmed the preservation of the nanotube morphology after modification, while XPS and STEM analyses indicated the deposition of Ce- and W-containing species on the nanotube surface. Optical properties were investigated by UV–vis absorption spectroscopy and photoluminescence. For the TiNTs@CeW sample, a significant reduction in the band gap from (3.23 ± 0.04) eV to (2.52 ± 0.03) eV was observed, as well as an increase in the Urbach energy from (0.316 ± 0.003) eV to (0.444 ± 0.001) eV, compared to NaTiNTs. These effects are associated with a higher concentration of oxygen holes and localized electronic states, which act as emission centers and temporary charge traps. The TiNTs@CeW showed significantly superior photocatalytic performance, promoting 73.84% degradation of tetracycline in high-concentration solution and exhibiting good stability and reusability. NaTiNTs achieved only 26.28% degradation under the same experimental conditions. These results highlight the potential of nanocomposite TiNts@CeW as effective materials in environmental remediation through their good photocatalytic performance in the degradation of the drug tetracycline.