Silver-Doped BaSrTiO₃ Nanocomposite: Synthesis, Characterization, Antibacterial and Photocatalytic Activities

Abstract

In this research, strontium titanate (SrTiO3), barium titanate (BaTiO3), barium strontium titanate (BaSrTiO3), and Ag-doped BaSrTiO3 nanocomposites with different Ag contents were fabricated using the sol–gel chemical route. The prepared samples were characterized by several techniques including scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), differential reflectance spectroscopy (DRS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), inductively coupled plasma spectroscopy (ICP), and Brunauer-Emmett-Teller (BET) measurement. The EDS results indicated that the synthesized nanoparticles had a cube perovskite-like structure. The EDS and ICP results revealed that Ag was doped into the Ba0.5Sr0.5TiO3 structure. The SEM and TEM images demonstrated that the particle size of 15 mol% Ag-doped Ba0.5Sr0.5TiO3 was smaller than that of pure Ba0.5Sr0.5TiO3 as confirmed by surface area results. The photocatalytic properties of undoped titanate samples and Ag-doped Ba0.5Sr0.5TiO3 were studied by the photodecomposition of Eosin yellowish (EY) and methylene blue (MB) dyes. The results illustrated that the photodegradation efficiency of the Ag-doped Ba0.5Sr0.5TiO3 was far higher than the undoped titanate sample, and the optimum Ag doping was 15 mol%. The antibacterial activities of pure Ba0.5Sr0.5TiO3 and Ag-doped Ba0.5Sr0.5Ti03 were studied against Staphylococcus aureus as Gram-positive (+) and Pseudomonas aeruginosa and Escherichia coli as Gram-negative (−) bacteria. In comparison with the bare Ba0.5Sr0.5TiO3 nanoparticles, the Ag-doped sample showed a significant enhancement in antibacterial activities against both Gram-negative and Gram-positive bacterial strains.

Doping Sr and Introducing Oxygen Vacancies in Ba0.7Sr0.3TiO3‐X Synergistically Promote the Pyro‐Photo‐Electric Catalysis Performance

“…Moreover, the volume change will affect the change of the pyroelectricity of the material. [39,43,44] For the introduction of oxygen vacancies in Ba 0.7 Sr 0.3 TiO 3 , the structural defects are studied by electron spin resonance (ESR) method. As shown in Figure 4a, pure BaTiO 3 could not observe any peak signal, but a peak signal appeared after the incorporation of Sr element, which come from the unpaired electrons captured by the defect in the crystal.…”

“…This change can be attributed to the volume shrinkage effect of the unit cell. Moreover, the volume change will affect the change of the pyroelectricity of the material [39,43,44] …”