Leela, N. SharonN. SharonLeelaKannan, S.S.KannanAbisheik, T.T.AbisheikPandiyan, V.V.PandiyanAlanazi, Abdullah K.Abdullah K.AlanaziRaja, A.A.RajaKalakonda, ParvathaluParvathaluKalakondaThirumurugan, ArunArunThirumuruganSandoval-Hevia, GabrielaGabrielaSandoval-HeviaBalu, KrishnakumarKrishnakumarBalu2026-07-072026-07-072025SURFACES AND INTERFACES, 76, 107909 (2025). https://doi.org/10.1016/j.surfin.2025.1079092468-0230https://hdl.handle.net/20.500.12740/24815The relentless discharge of synthetic dyes from industrial sectors poses severe threats to aquatic ecosystems and public health due to their toxicity, persistence, and resistance to conventional treatment methods. Addressing these concerns, we developed a urea-modified terbium-doped titanium dioxide (Tb-U-TiO2) photocatalyst via a sol-gel technique followed by thermal treatment. The synergistic effect of Tb3+ doping and urea modification enhanced crystallinity, extended visible-light absorption, and suppressed charge recombination. Comprehensive characterization using XRD, FT-IR, Raman, FE-SEM, HR-TEM, XPS, PL, and UV-DRS confirmed structural, morphological, and optical improvements. Photocatalytic activity was assessed by degrading Acid Black 1 (AB 1) under UV-C and Reactive Red 120 (RR 120) under natural sunlight. The optimized 0.4 wt% Tb-U-TiO2 catalyst achieved complete degradation of AB 1 and 96.87% removal of RR 120, outperforming unmodified U-TiO2. Kinetic studies revealed pseudo-first-order behaviour, and parameter optimization established ideal pH and catalyst loading conditions. GC-MS analysis identified key intermediates and proposed a degradation pathway. Radical scavenging experiments confirmed that O2 center dot- and h+ were the dominant active species. Beyond dye removal, the catalyst exhibited strong antibacterial activity against both Gram-positive and Gram-negative strains, demonstrating its dual functionality in pollutant degradation and microbial disinfection. The material also showed excellent stability and reusability over multiple cycles with negligible performance loss. Overall, this work presents Tb-U-TiO2 as a cost-effective, solar-responsive, and multifunctional photocatalyst with significant promise for next-generation integrated wastewater treatment and environmental protection.PhotocatalysisTerbium-doped U-TiO 2UV-C and Solar lightDye breakdownMicrobial disinfectionArticulohttps://doi.org/10.1016/j.surfin.2025.107909