Synthesis and characterization of Sn‑doped TiO2 flm for antibacterial applications

Simple sol–gel method has been exploited to deposit Sn-doped TiO2 thin flms on glass substrates. The resultant coatings were characterized by X-ray difraction (XRD), UV–visible techniques (UV–Vis), Fourier transform infrared spectroscopy (FTIR), and photoluminescence analysis (PL). The XRD pattern reveals an increase in crystallite size of the prepared samples with the increasing doping concentration. A decrease in doping concentrating resulted in the decrease in bandgap values. The diferent chemical bonds on these flms were identifed from their FTIR spectra. The photoluminescence analysis shows an increase in the emission peak intensity with increasing dopant concentration, and this can be attributed to the efect created due to surface states. The prepared samples were tested as antibacterial agent toward both Gram-positive and Gram-negative bacteria like S.aureus (Staphylococcus aureus) and E.coli (Escherichia coli), respectively. The size of the inhibition zones indicates that the sample shows maximum inhibitory property toward E.coli when compared to S.aureus

Optimization of Deposition Parameters on the Physical Properties of TiO2 Thin Films by Spray Pyrolysis Technique

Titanium dioxide (TiO2) thin films have been deposited on microscopic glass substrate by spray pyrolysis technique. The effect of deposition parameters such as substrate temperature, molarity (precursor concentration) and solution spray rate on the structural, surface morphological and optical properties of the films have been studied. The prepared films were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) with EDS and UV-Vis spectroscopy. The XRD patterns indicated that the films have amorphous and polycrystalline structure and the size of the crystallites have been changed from 9 to 48 nm. The optical band gap of the TiO2 films is determined to be about 3.40 to 3.65 eV to the change of deposition conditions

Applications of FTIR and 57Fe\text{}^{57}Fe Mössbauer Techniques in Studies of Recently Excavated Indian Archaeological Pottery

The Fourier transform infrared absorption spectra and $\text{}^{57}Fe$ Mössbauer spectra have been recorded at room temperature for the recently excavated archaeological pottery sherds. FTIR spectroscopy is used to estimate the lower limit of firing temperature and firing nature of the pottery sherds, and it is confirmed by the results of the Mössbauer technique results. The results show that the $\text{}^{57}Fe$ Mössbauer and FTIR spectra of few pottery sherds of Perumalpattu and Theriruveli are nearly identical, indicating that they may belong to the same origin. $\text{}^{57}Fe$ Mössbauer spectra of black coloured sherds show the presence of $Fe^{2+}$ ions which confirm the relation between the black colour in pottery and the existence of non-magnetic FeO compound, resulting from the reducing atmospheric condition during firing. FTIR results of reddish pot sherds show the presence of significant amount of $Fe_2O_3//α-Fe_2O_3$, which confirms again the relationship between the state and form of iron present in the pottery and its colour