Relation between physical properties, enhanced photodegradation of organic dyes and antibacterial potential of Sn_1 − xSb_xO₂ nanoparticles

Sn_1 − xSb_xO₂ (0 ≤ x ≤0.1) nanoparticles were synthesized by chemical solution method using organic solvent. Antibacterial and photocatalytic activities of the prepared nanoparticles were discussed based on structural, compositional and optical properties. The X-ray diffraction patterns indicated that the Sb doping decreased the crystallite size and lattice parameters of SnO₂ nanoparticles while the compressive strain and dislocation density of cassiterite phase increased. The X-ray photoelectron spectroscopy spectra of Sn_1 − xSb_xO₂ confirmed that Sb ions substituted at Sn⁴⁺ sites with +5 valance state. Field emission scanning electron microscopy showed that the nanoparticles possess spherical shape and Sb doping decreased the grain size. UV–Vis absorption spectra revealed that the substitution of Sb in SnO₂ lattice leads to band gap narrowing from 4.06 to 3.85 eV. Photoluminscence spectra of Sn_1 − xSb_xO₂ nanoparticles disclosed a green emission due to the presence of oxygen vacancies and Sn_0.95Sb_0.05O₂ had highest emission intensity among all samples. The Sn_1 − xSb_xO₂ nanoparticles exhibited enhanced photodegradation of rhodamine B and methylen blue dyes under UV illumination compared to the undoped SnO₂. The bactericidal activity of Sn_1 − xSb_xO₂ nanoparticles was investigated against bacterial pathogens including E. coli, P. aeruginosa, and S. aureus. The results revealed that antibacterial and photocatalytic activities of nanoparticles strongly depend on reactive oxygen species and structural parameter of the nanoparticles.