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Nanoparticles of titanium dioxide (TiO2NPs) have been synthesized and the effects of annealing temperatures have been studied using sol–gel techniques on particle size, optical properties and structures. X-Ray Diffraction (XRD), Raman Spectra, photoluminescence, UV/Visible spectroscopy and scanning electron microscopy (SEM) are used to depict TiO2 nanopowders (PL). From XRD results, nano sized TiO2 (15 nm, 19 nm, 26 nm, & 29 nm) was observed and revealed that pure anatase and routine phase with tetragonal structure were developed. Annealing temperatures gives the transformation of phasesy from anatase to rutine. Particles size, lattice parameters and diffraction intensity of synthesized TiONPs were increased as annealing temperature increases while, full width at half maxima and grain sizes decreased. Uniformly distributed cylindrical shapes of TiO2NPs were observed from SEM images and increases in size with increasing annealing temperatures from 400 °C to 1000 °C. Highly transparent nanopowders are observed in visible region from UV/Visible and red shift towards higher wavelength with increasing annealing temperatures are due to an increment in particle from XRD results and SEM images. The energy band gap of synthesized nanopowders has been reduced with rising annealing temperatures that correspond to the red shift of the optical absorption edge. Raman Spectra has also been characterized by the structural properties of synthesized nanoparticles and demonstrates the existence of anatase and routine tetragonal levels. The overall reduced strength was observed from the results of the PL.

In this work, image quality and optical coherence tomography were studied. The results of the study show that there is a very significant difference between ultrasound and optical coherence tomography to produce an image with a different wave. To understand this, we studied the basic principle of optical coherence tomography in the Michelson interferometer using monochromatic and broadband sources. Time-domain and spectral-domain measurements, which exist at the detector level, are briefly described using a glass sample. The time-domain signal strength of the Michelson interferometer using a broadband source is a Gaussian envelope.

The production of zinc oxide nanoparticles (ZnO NPs) utilizing different vegetable extracts (onion, cabbage, carrot, and tomato) was performed in this research owing to its excellency over other methods of synthesis, namely, simplicity, environmental friendliness, and the elimination of harmful compounds. Fresh extracted onion, cabbage, carrot, and tomato of ZnO NPs are characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-visible spectroscopy. FTIR findings demonstrate that the prepared nanoparticles were observed in the spectrum of 626 cm-1–1219 cm-1 with some other functional groups. Wurtzite hexagonal structure of the prepared ZnO NPs was observed from XRD results. In addition, the prepared nanoparticles were failed into nanoscales (17 nm, 18 nm, 24 nm, and 15 nm) calculated from Scherrer’s equation. Nearly spherical shapes were seen from SEM image for onion and tomato extraction while rod and tube for carrot and cabbage, respectively. Two broad peaks were observed from UV-vis spectroscopy results for each extract. The presence of a wide range of energy bandgaps in the region of 3-4 eV was detected, indicating that ZnO NP material can be employed in metal oxide semiconductor-based systems. The dye-sensitive solar cell based on ZnO NPs has been successfully synthesized, and the efficiency of the device has been evaluated by measuring the current density-voltage behaviour under the presence of artificial sunshine. The increased effectiveness of the manufactured dye-sensitive solar cell is attributable to a large improvement in dye molecular adsorption onto the surface of ZnO NPs. Thus, the usage of the green produced ZnO NPs with creating dye sensitivity solar cell is a simple and viable way for the well-being of our future.

Comparison of green and chemical precipitation method syntheses of zinc oxide nanoparticles (ZnO NPs) was performed, and antimicrobial properties were investigated. Avocado, mango, and papaya fruit extracts were carried out for the green synthesising methods, while the chemical precipitation method was chosen from chemical synthesis methods. Zinc nitrate was used as a salt precursor, whereas leaf extract was served as a reducing agent for green synthesising methods. In addition, sodium hydroxide, polyvinyl alcohol, and potassium hydroxide were used as reducing agents in the case of chemical precipitation synthesis methods. ZnO NPs were characterised by characterizing techniques such as Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The antimicrobial activities of prepared nanoparticles were evaluated on Bacillus subtilis (B. subtilis), Staphylococcus aureus (S. aureus), and Salmonella typhimurium (S. typhimurium). The particle sizes of the prepared samples which were evaluated by the Scherrer equation were in the range of 11-21 nm for green synthesis, while 30-40 nm for chemical precipitation synthesis methods. Small agglomerations were observed from SEM results of prepared ZnO NPs from both methods. Prepared ZnO NPs were showed strong antimicrobial properties. From the result, the inhibition zone was in the range of 15-24 mm for the green route and 7–15 mm for chemical precipitation methods, where the standard drugs have 25 mm of the zone of inhibition. A green synthesised method of preparing ZnO NPs gives promising antimicrobial properties compared to chemical synthesis and is also eco-friendly and safe compared to the chemical synthesis.