Impact of Ionic Liquids on the Crystal Growth and Surface Morphology of Ruthenium-doped TiO2 Nano Heterojunction Structures for Improved Photocatalytic Degradation of Evans Blue Dye and the Associated Antibacterial Activities
antibacterial activity; hydrothermal method; ionic liquid; photocatalytic degradation; Ru/TiO2 nanocomposite
Novel Ru-doped TiO2 nanocomposites (Ru/TiO2 NCs) were synthesized at a 130 C temperature and 24-h incubation period using hydrothermal methods with and without ionic liquids (ILs). NCs were synthesized using 1-butyl-2,3-dimethylimidazolium tetrafluoroborate as the ILs and titanium(IV) isopropoxide and ruthenium(III) nitrate as the precursors. The presence of Ru in the NCs was analyzed using different characterization techniques. Powder X-ray diffraction and transmission electron microscopy confirmed the presence of anatase and rutile phases as well as the nanocrystalline texture of the prepared Ru/TiO2 NCs. The presence of Ru, Ti, and O was confirmed via energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The optical properties and bandgap energies of Ru/TiO2 NCs were determined via ultraviolet (UV)visible (Vis) diffuse reflectance spectroscopy; the optical properties exhibited a redshift in the optical response toward the visible region owing to the reduced bandgap energy of Ru/TiO2 NCs in the visible region after doping Ru into the TiO2 nanocrystalline structure. Scanning electron microscopy images revealed a highly voluminous and porous network of Ru/TiO2 NCs. Moreover, different concentrations of Ru were doped into the TiO2 matrix to investigate the photocatalytic and antibacterial activities. Among all the synthesized NCs, 0.3-wt% Ru/TiO2 NCs exhibited high photocatalytic degradation efficiency and was therefore considered the optimum concentration. Moreover, it exhibited the highest BET surface area and quantum efficiency compared with other Ru/TiO2 NCs. Results revealed that Ru/TiO2 NCs synthesized via IL-assisted hydrothermal method, i.e., R3TL, exhibited considerably enhanced photocatalytic and antibacterial activities compared to the NCs synthesized without the ILs, i.e., R3TH. The inhibition pattern showed an excellent zone of inhibition (p < 0.001) in several strains with both NCs (R3TL and R3TH). However, Gram-positive Staphylococcusaureus exhibited a remarkably increased zone of inhibition (35 mm) compared with all the other strains used for R3TH. In contrast, Bacillus sp. exhibited the second largest zone of inhibition (21 mm) for R3TL after S. aureus (34 mm). In summary, this study emphasized the role of ILs and reaction mechanisms. The author(s) 2025.
Ravishankar, T.N.; Ananda, A.; Adarsha, J.R.; Shilpa, B.M.
Nano Biomedicine and Engineering;Volume;17;Issue;4;pp.570-588
All Open Access; Gold Open Access; Green Open Access
https://doi.org/10.26599/NBE.2024.9290093 https://www.scopus.com/pages/publications/105016215847?origin=resultslist
Ravishankar T.N., Department of Chemistry, B.M.S. College of Engineering, Karnataka, Bangalore, 560019, India; Ananda A., Department of Chemistry, Dayananda Sagar Academy of Technology & Management Udayapura, Bengaluru, 560082, India; Adarsha J.R., Department of chemistry, Global Academy of Technology, Ideal Homes Township, Karnataka, Bangalore, 560098, India; Shilpa B.M., Department of Psychology, Christ-Deemed to be University, Bangalore Kengeri Campus, Karnataka, Bangalore, 560074, India