Optical Characteristics Of Samples Research Articles

Chemical bath co-deposition of Co3O4 and In2O3 on TiO2 nanotubes, aiming for photoanodes with improved photoelectrochemical properties

This study investigates the implications of the deposition of Co3O4 and In2O3 onto TiO2 nanotube thin films for the photoelectrochemical activity of TiO2 nanotubes (TNTs). Initially, TiO2 nanotubes were fabricated through an electrochemical anodizing process. Subsequently, a facile chemical bath deposition (CBD) method was used to deposition Co3O4 and In2O3 oxides. The resulting composites are used as photoanodes for the photoelectrochemical cathodic protection of AISI304 stainless steel (304SS) in marine environments. The surface morphology, compositions, crystalline structures, and optical characteristics of samples were examined using a combination of FESEM, TEM, EDX, XPS, XRD, and UV-Vis absorption spectroscopy. Electrochemical measurements under both illuminated and dark conditions were conducted to assess the photoelectrochemical characteristics of synthesized samples. The optimal co-deposited photoanode, significantly shifted the open circuit potential of the coupled AISI 304SS to −708 mV under intermittent light exposure, demonstrating appropriate photocathodic protection (PCP) performance. This potential was further enhanced and maintained at −720 mV for an hour in continuous light tests. Additionally, the photoanodes showed some degrees of delayed cathodic protection even after the light was switched off. The Co3O4-In2O3-modified TNTs composite exhibits superior photoelectrochemical cathodic protection activity due to the synergistic effects of Co3O4 and In2O3 nanoparticles.

Electron Beam Deposition of Lanthanum Hexaboride Films for Usage as Anti-Reflective Coating

The development of effective anti-reflective coatings of electromagnetic radiation is a necessary basis to solve a wide range of fundamental and applied problems. We studied the conditions for the preparation of lanthanum hexaboride (LaB6) films by electron beam deposition on Al2O3, AlN, ZrO2, Si, and W substrates, and CeB6 and W coatings. The phase and elemental composition, the microstructure and optical characteristics of samples obtained under various deposition conditions were studied. The relationship between the reflection spectra and the surface roughness of the samples was investigated. The region of the electromagnetic spectrum in which the obtained films can be used as anti-reflection coatings is determined.

Influence of Gamma-Irradiation on Structural, Optical and Photocatalytic Performance of TiO2 Nanoparticles Under Controlled Atmospheres

The effect of gamma-rays on structural, optical and photocatalytic properties of TiO2 nanoparticles under controlled atmospheres are studied to further improve photocatalytic performance. The sol–gel TiO2 powders were deposited with spin-coating technique, annealed at 500°C then finally irradiated by gamma-rays. The structural and optical characteristics of samples were investigated by Fourier transform infrared spectroscopy, x-ray diffraction and UV-visible spectroscopy (UV). The time-dependent density functional theory (TD-DFT) calculation are used to determine ground geometries and electronic structures of TiO2 nanostructures. DFT calculations present an excellent conformity with experimental results, and a high anisotropy in stretched thermal and electrical conductivity TiO2 nanostructures was found. Structural and optical results show that gamma radiation did not change the crystallinity of TiO2 nanostructures and leads to an optical band gap reduction to 3.039 eV. The gamma radiation effect on photocatalytic performance was investigated by methylene blue degradation as a typical pollutant. Gamma radiation has been discovered to improve considerably the degradation of pollutants compared with unirradiated TiO2.

Multilayer thin-film filters of extreme ultraviolet and soft X-ray spectral regions

Multilayer thin-film filters from different materi al pairs with spectral windows within the wavelength range 7n < 60 nm were developed. Optical characteristics of samples in the extreme ultraviolet, visible, and IR spectrum ranges were studied. Ultrathin freestanding Zr/Si large-aperture filters with transparencies up to 76% at 7n = 13 nm were manufactured for projection lithography test benches; variations in their properties during long-term thermal loads were studied.