Photocatalytic, antibacterial and optoelectronic applications of Terbium doped Zinc oxide nanoparticles prepared via chemical co-precipitation method

This work demonstrates facile synthesis of Tb-doped ZnO nanoparticles and investigates their structural, optical, electrochemical, photocatalytic, and antibacterial performance. XRD patterns of undoped and doped ZnO nanoparticles confirm a hexagonal wurtzite structure. TEM and SAED reveals that the particle size is 14-38 nm. SEM images show that ZnO and Tb-doped ZnO nanoparticles have smooth surfaces, and elemental composition was confirmed by EDX analysis. UV-Visible spectrophotometry studies, reveals that the band gap narrows with increasing Tb concentration. Photoluminescence spectra at room temperature showed a band at 538 nm, indicating zinc vacancies and green emission. Tb-doped ZnO with x = 0.075 exhibited the highest photocatalytic activity for degrading Rose Bengal dye compared to other photocatalysts. The electrochemical behaviour of Catechol (CC), Hydroquinone (HQ), and Bisphenol-A (BPA) at Tb-ZnO/MCPE was studied. The modified electrode process for CC and BPA was adsorption-controlled, and simultaneous recognition of CC, HQ, and BPA was achieved, showing an increase in current. Electro polymerization of poly (Congo red) on Tb-ZnO/MCPE confirmed clean deposition on the surface, enhancing electrocatalytic activity. The antibacterial efficacy was tested using the traditional disc diffusion method, showing effective inactivation of bacterial strains, including pathogens such as S. aureus (G+) and E. coli (G-).