Bi-doped BaBiO3 (x = 0%, 5%, 10%, 15%, and 20%) perovskite oxides by a sol-gel method: comprehensive biological assessment and RhB photodegradation

Abstract

The BaBiO₃ (BBO) perovskite oxide was prepared via a sol-gel method with different concentrations of Bi nitrate and examined as a photocatalyst for RhB degradation under sunlight, and its antioxidant and antibacterial activities were examined. X-ray diffraction (XRD) indicated the formation of a BaBiO₃-BaCO₃ (BBO-BCO) binary composite. For the degradation of RhB under solar radiation, high photocatalytic activity (73%) was observed. According to the antibacterial activity study, the addition of Bi enhanced the antibacterial activity of the resulting material against both Gram-positive and Gram-negative microorganisms. The Bi%-BBO (Bi 20%) inhibited 96.23% S. aureus. 10% Bi-BBO as an antioxidant agent had the most efficacious IC50 value of 2.50 mg mL^-1. These results seem to suggest that BBO-BCO is a promising catalytic material with potential application in the fields of catalysis and medicine.

Fig. 1. TG curves of BaBiO₃–BaCO₃ (pure – 20% Bi) precursors heated in air at 5° min⁻¹.

Fig. 2. XRD patterns of the BBO–BCO powders with different excess of Bi.

Fig. 3. (a) Evaluation of the highest X-ray diffraction peak positions for BBO and BCO, (b) BCO and BBO composition as a function of Bi content (%), (c) dependence of lattice volume on bismuth content for BBO and BCO and (d) plot showing the evaluation of average crystallite size of Bi%–BBO with Bi wt. (%).

Fig. 4. FTIR spectra of % Bi–BBO powder samples calcined at 900 °C.

Fig. 5. (a) UV-Visible reflectance spectra and (b) graph used for band gap estimation of Bi%–BBO.

Fig. 6. Micrographs and particle size histograms for BaBiO₃–BaCO₃: (a) pure BBO, (b) 5% excess Bi, (c) 10% excess Bi, (d) 15% excess Bi, and (e) 20% excess Bi particles.

Fig. 7. (a) EDS spectrum of the as-prepared sample (20% excess Bi) and (b) variation in Bi wt% as a function of Bi content.

Fig. 8. Absorption spectra of RhB by BBO–BCO NPs under solar energy for different durations: (a) 0% Bi–BBO, (b) 5% Bi–BBO, (c) 10% Bi–BBO, (d) 15% Bi–BBO, and (e) 20% Bi–BBO.

Fig. 9. (a) Relationship between degradation efficiency and crystallite size and (b) recycling of Bi%–BBO for the photodegradation of RhB.

Fig. 10. Nonlinear fitting of (a) PFO and (b) PSO models for RhB degradation.

Fig. 11. Schematic illustration of basic mechanism.

Fig. 12. (a) DPPH radical scavenging activity of % Bi–BBO and ascorbic acid. (b) Relationship between IC50 DPPH and crystallite size.

Fig. 13. Bacterial inhibition (%) of pure BBO and BBO with different excess Bi (%) against E. coli and S. aureus.