Enhanced photocatalytic and antibacterial activity of TiO2 Quantum dots doped with Cerium/Chitosan for Environmental Remediation: Experimental and theoretical approaches

The co-precipitation approach was adopted to synthesize ternary nanocomposites composed of Cerium-Ce, Chitosan-CS, and TiO2 quantum dots (QDs). Different Ce concentrations (2 and 4 wt %) were doped into the fixed amounts of CS and TiO2 QDs. The purpose of the current work was to assess the antimicrobial and pho-tocatalytic activities of Ce/CS-TiO2. The XRD study confirmed the tetragonal structure of TiO2, whereas the presence of dopants (CS and Ce) in TiO2 resulted in a decrease in crystallite size. The microstructural exami-nation of the composites through HR-TEM suggested the formation of quantum dot structures. FTIR revealed the functional groups presence in the synthesized product and absorption spectra were collected through UV-vis spectrophotometer accompanied redshift therefore, decreased in band gap energy of Ce and CS doped TiO2 was observed. PL spectroscopy was used to identify trap locations and charge carrier migration. SEM-EDS analysis validated the presence of dopants in the product and confirmed elemental composition. After incorporating 2% Ce into CS-TiO2, the MB dye dissolved considerably, dye degradation was of 97% in basic medium. Significant antibacterial activity was observed against both Staphylococcus aureus and Escherichia coli (S.A and E.A) bacteria. The adsorption energies of the CS/Ce-TiO2 nanocomposites were investigated using density functional theory, revealing the formation of stable structures.

Automated summary

The co-precipitation approach was used to synthesize ternary nanocomposites consisting of Cerium-Ce, Chitosan-CS, and TiO2 quantum dots (QDs). The purpose of this study was to evaluate the antimicrobial and photocatalytic activities of Ce/CS-TiO2. The results showed that the addition of dopants (CS and Ce) decreased the crystallite size of TiO2 and resulted in the formation of quantum dot structures. The Ce/CS-TiO2 nanocomposites exhibited significant antibacterial activity and showed a redshift in absorption spectra, indicating a decrease in band gap energy.