Ultraviolet Visible Near-infrared Spectrophotometer Research Articles

Sustainable reutilization of ion-adsorbed rare earth tailings: Preparation of low-cost functionalized pigments

In order to alleviate the ecological pressure caused by rare earth tailings, this study focuses on the application of ion-adsorbed rare earth tailings in the preparation of functional pigments. By using mechanical grinding and high-temperature calcination, 33 new functionalized red pigments were successfully prepared by doping iron and lanthanum elements. X-ray diffraction (XRD), scanning electron microscopy (SEM), CIE 1976 color space system, and ultraviolet–visible–near-infrared spectrophotometer were used for characterization. The synthesized pigment exhibits a rich color range from light yellow to reddish brown. Compared with commercially available iron red pigments, it exhibits significantly enhanced near-infrared reflectance, excellent acid and alkali resistance, and strong thermal stability up to 900 °C. It is worth noting that pigment P-1-2-1 achieved the best red value (L* = 43.73, a* = +24.07, b* = +15.65) with a maximum near-infrared reflectance of 91 %. Therefore, the utilization of rare earth tailings as raw materials for the preparation of functional pigments has significant effects. This study provides valuable insights for the development of eco-friendly pigments, which not only helps alleviate the urban heat island effect but also promotes the sustainable utilization of rare earth tailing resources, contributing to the achievement of carbon neutrality goals.

Preparation and thermochromic properties of B-Mg co-doped nano-VO<sub>2</sub>

In order to reduce the phase transition temperature of vanadium dioxide (VO₂) materials and improve the optical properties of VO₂ materials, the boron-magnesium (B-Mg) co-doped vanadium dioxide (VO₂) powders were prepared through a sol-gel-assisted hydrothermal method in combination with the subsequent high-temperature annealing. The obtained powder was further prepared into a thin film. X-ray diffraction (XRD), X-ray electron spectroscopy (XPS), field emission scanning electron microscope (FESEM), differential scanning calorimeter (DSC), ultraviolet-visible-near-infrared spectrophotometer (UV-vis-NIR) were used to explore the microstructure of the material and effects of the doping concentrations of Mg on the phase transition temperature <italic>t</italic>_c and the optical properties of VO₂ materials. The B-Mg co-doped nano-VO₂ material that satisfies various application standards was obtained. The results show that the doped elements of B and Mg exist in the VO₂ structure as the form of B³⁺ and Mg²⁺. When the atomic percentages of B and Mg are 6.0% and 1.8%, the material shows a relatively excellent thermochromic properties, with the lowest phase transition temperature <italic>t</italic>_c = 30.8 ℃. The sunlight modulation amplitude Δ<italic>T</italic>_sol of the material is 11.8%, which is maintained above 10%. The average visible light transmittance <italic>T</italic>_lum of the material is 69.7%, which is 12.1% higher than that of the undoped VO₂ film. The properties above meet the requirements for the application in thermochromic smart windows. This work provides scientific basis for the preparation of VO₂ materials suitable for thermochromic smart windows.

Effect of Benzalkonium Chloride on Properties of Zinc Oxide Nanoparticles Synthesized through Sol-Gel Technique

In the present study, to synthesize controllable sized metal oxide particles, benzalkonium chloride (BAK) as cationic surfactant was added to zinc oxide (ZnO) nanostructures synthesis at room temperature using sol–gel method. The effect of cationic surfactant BAK concentrations, on the optical properties, size, and morphology of ZnO nanoparticles synthesized through sol–gel method was studied. The characterization of ZnO nanostructures was occurred using transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet–visible near infrared (UV-Vis) spectrophotometer, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). ZnO nanostructures shape and size were revealed by SEM and TEM. The hexagonal (wurtzite structure) of ZnO was confirmed by an X-ray diffractogram. The bandgap energy of the prepared ZnO samples was determined by UV-Vis spectrophotometer. FTIR analyzed the presence of functional groups.

Structure and optical properties of CrOxNy films with composition modulation

ABSTRACTThe composition and structure properties of the CrOxNy films deposited by RF reactive magnetron sputtering were investigated and correlated with their optical properties. Two kinds of targets Cr2O3 and CrN compounds with variation of N2 and O2 gas flow were used to prepare two series of samples. The phase structure, chemical composition and optical properties of CrOxNy films were characterised by X-ray diffraction, X-ray photoelectron spectroscopy and ultraviolet–visible near-infrared spectrophotometer, respectively. The films mainly consist of Cr2N and CrO3 phases. The Cr/ON ratio derived by XPS varies with the variation of nitrogen with Cr2O3 target. But only lower nitrogen content is detected with variation of oxygen using CrN target. The CrOxNy films with higher nitrogen content possess high absorbance around at 35% in the visible light range no matter the target.

Transparent heat insulation coatings with high selective shielding ability designed with novel superstructures of copper sulfide nanoplates

In the present work, novel CuS superstructures composed of intersectional CuS nanoplates (CuS i-nanoplates) and snowflake-like CuS nanoplates (CuS s-nanoplates) were successfully synthesized at a low temperature (80 °C) by a simple chemical precipitation method. It has been found that the as-synthesized CuS superstructures were formed by the growth of CuS i-nanoplates along the direction perpendicular to the basal nanoplate with a thickness of 29.64 ± 3.16 nm and CuS s-nanoplates were prepared with the snowflake-like morphology with a thickness of 16.82 ± 3.62 nm. Subsequently, a new transparent heat insulation coating with CuS superstructures composed of CuS i-nanoplates as NIR shielding agent (coded as H–X coating) was prepared by mixing with acrylic-amino-alkyd baking varnish and coating to ordinary glass substrates. Simultaneously, another transparent heat insulation coating with s-nanoplates (coded as S–X coating) was also synthesized. Optical properties of those coatings were studied as a function of the CuS content by using ultraviolet–visible–near-infrared spectrophotometer. And the H–X coatings were shown to have a higher selective shielding ability for solar light than S–X coatings since the shielding ability of S–X coatings in the region of 1180–2500 nm rapidly weakened with increasing wavelength. The comparative study on the properties of nanomaterials with different morphologies in this paper may provide some new guidance for material design to improve its performance. Moreover, the CuS superstructure-based transparent heat insulation coatings with excellent NIR shielding property have a potential application in energy-saving windows for architectures and vehicles.

Tellurite suboxide based near-infrared reflector and filter

TeO1.4/SiO2 one-dimensional photonic crystals (1D PCs) were prepared using radio frequency (RF) magnetron sputtering to fabricate a reflector and a filter with photonic band gaps (PBGs) in the near infrared (NIR) region. Stoichiometry and phase state of the TeOx thin film were characterized via X-ray photoelectron spectroscopy (XPS) and X-Ray Diffraction (XRD), respectively. The microstructural and optical characteristics of the 1D PCs were evaluated using scanning electron microscopy (SEM), atomic force microscopy (AFM) and ultraviolet visible near-infrared spectrophotometer (UV-VIS-NIR). The experimental reflectance spectra were consistent with the theoretical results simulated using the transfer matrix method (TMM). For the reflector, a PBG of 1273–1676 nm (Δλ = 403 nm) was achieved in the NIR region. For the filter, the introduction of a defect layer in the 1D PC led to a resonant peak at the central wavelength of 1461 nm within the PBG of 1250–1733 nm (Δλ = 483 nm). The effects of the structural parameters, including the incident angle, the state of polarization and the thickness of the defect layer, were also theoretically analyzed.

Bio-inspired self-assembly of waxberry-like core-shell SiO2@TiO2 nanoparticles towards antiglare coatings.

Waxberry-like core–shell SiO2@TiO2 nanoparticles were prepared by liquid-phase deposition (LPD) method. The dip-coating self-assembly of waxberry-like core–shell SiO2@TiO2 nanoparticles has been used to fabricate coatings with excellent antiglare properties in the large angle and wide wavelength range. The field emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM) measurements showed that the surface of SiO2 nanoparticles were coated by titania as a shell with controllable and uniform thickness. The ultraviolet visible near-infrared spectrophotometer (UV-Vis-NIR) results indicate that the maximum transmittance of the antiglare coating is up to 95.80% in the visible band, whereas that of the pure glass substrate is only 92.10%. The scattering and haze of the films have been measured to show that such specifically structured coatings exhibited good antiglare properties in the large angle and wide wavelength range.

Preparation and Coloration of Colored Ceramics Derived from the Vanadium-Titanium Slags

Vanadium-titanium slag is a type of industrial solid waste from vanadium-titanium magnetite, and the resource utilization of vanadium-titanium slag is of great significance. The chemical composition of vanadium-titanium slag is similar to ceramic raw materials. Besides, the Fe, Ti, and Mn elements in vanadium-titanium slags possess strong color rendering ability. In the present study, we explored the influence of Fe, Ti, and Mn in vanadium-titanium slags on the coloration of ceramics. Besides, the crystal structures and chemical constituents of the sintered ceramics were studied by XRD, SEM, EDS, XPS, and ultraviolet-visible near-infrared spectrophotometer, and the color-rendering ability (L∗a∗b∗ values) of the ceramics was investigated. The results showed that the main crystal phases of the ceramics were quartz and anorthite. In addition, the color of the ceramics with the addition of vanadium-titanium slags was significantly affected by Fe and Mn ions, which decreased their L∗ and a∗ values. Meanwhile, Ti ion alone had no apparent coloring effect but strengthened the coloring effects of Fe and Mn ions. This work could provide the feasibility for preparation of colored ceramics based on vanadium-titanium slag, which could be used in the fields of high-value added building decoration, infrared-emission ceramic, and artwork.

Visible light-induced super-hydrophilic anatase porous thin film with easy-to-clean and antifogging properties

Atmospheric dust on the surface of modern building glass requires frequent cleaning to keep high diaphaneity and esthetics. Visible light-induced super-hydrophilic anatase porous thin films with easy-to-clean and antifogging properties were controllably synthesized through the neutralization of ammonia and nitric acid-driven phase separation by sol–gel spin coating method. Surface microstructure, root-mean-squared roughness, crystalline structure, surface chemical composition, transmittance, hydrophilic, antifogging, and easy-to-clean properties of the films were characterized by super depth of field microscopy, atomic-force microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet–visible–near-infrared spectrophotometer and automatic contact angle measuring device, respectively. With NH3·H2O concentration increasing from 0.7 to 1.1 vol.%, the average pore size of anatase porous thin films increases from 1.05 to 2.36 μm and the water contact angles decrease from 5.2° to 1.7° under 100-lux visible light irradiation (400–800 nm). Besides, the larger NH3·H2O concentration, the larger root-mean-squared roughness roughness, ranging from 5.67 to 88.00 nm. Moreover, X-ray photoelectron spectroscopy results demonstrate that there are Ti–O bonds and Si–O bonds on the samples surface, indicating that porous area bottom is Si–O bonds by soda-lime glass. These films exhibit excellent visible light-induced super-hydrophilic, antifogging and easy-to-clean properties, which make them suitable to be used in modern buildings and automotive glass.

Surface modification nanoporous titanium oxide films using continuous wave CO2 laser

This study investigated the characteristics of titanium dioxide (TiO2) films modified through laser annealing by using a CO2 laser source (CSS 500 AIR, Spectral Inc., Italy) with a wavelength of 10,600 nm and a continuous wave mode. Commercial TiO2 thin films with a thickness of 100 nm were prepared through radio-frequency magnetron sputtering on soda-lime glass substrates. The optical properties (optical absorption and transmittance spectra), surface morphology, and surface chemical composition characteristics of the TiO2 films depended on the laser irradiation conditions. The characteristics of the films were systematically analyzed using a ultraviolet–visible near-infrared spectrophotometer, an X-ray photoelectron spectroscope, and a field emission scanning electron microscope. The experimental results demonstrated that the experimental transmittance spectra exhibited slight changes caused by laser annealing and a maximum transmittance in the visible region of approximately 91.4 %. The absorbance of all annealed TiO2 films exceeded that of as-deposited films. Moreover, the absorption band edge moved toward the long-wavelength side (red shift) as the annealing speed decreased because the heat applied during annealing caused the TiO2 film grains to grow. Diffusion and mobility between the films and glass substrates during laser annealing segregated elemental Ag.

Al 2 O 3 and Sn/Al 2 O 3 nanowires: fabrication and characterisation

Self-ordered anodised aluminium oxide membranes can be used as a base for the growth of different nanoarrays. In this reported work, an efficient and effective method is implemented to fabricate highly ordered alumina nanowires (ANWs) covered with a uniform shell of 12 ± 2 nm Sn nanoparticles (Sn/ANWs). A two-step anodisation process followed by a selective etching process was used to prepare highly ordered ANWs with diameters smaller than 36 nm. The thermal evaporation technique was used to ensure the deposition of a Sn nanoshell on the fabricated nanowires. The fabricated nanostructures were characterised by energy-dispersive X-ray spectroscopy, X-ray diffraction, field emission-scanning electron microscopy and an ultraviolet–visible–near-infrared spectrophotometer. Analysis of the scanning electron microscopy images showed that the etching rate is 0.73 nm/min and ANWs are obtained after etching the membrane for 110 min. The measured reflection spectra revealed that Sn/ANWs exhibit a redshift of the UV absorption band relative to the ANWs and a reflectance of nearly 100% in the near-infrared region. For optical comparison, glass slides were coated with Sn under the same conditions for 90 and 120 s. The reflection spectrum of the 120 s Sn-coated glass slide shows three modes at 210, 296 and 700 nm because of the excitation and interference of plasmonic waves.

快速退火对PLD法制备SnS薄膜结构和光学性质的影响

SnS thin films were grown by pulsed laser deposition on glass substrates at room temperature,and then the deposited films were rapidly annealed at 200,300,400,500,600 ℃ under flowing argon atmosphere. The effects of rapid thermal annealing( RTA) temperature on the microstructural,morphological,optical properties and electrical properties of Sn S thin films were studied by X-ray diffraction( XRD),laser Raman spectrometry( Raman),atomic force microscopy( AFM),field emission scanning electron microscopy( FESEM),ultraviolet-visible-near infrared spectrophotometer( UV-Vis-NIR) and Keithley 4200-SCS semiconductor parameter analyzer. The results show that SnS thin films grow preferentially oriented in the( 111) direction,and the crystalline quality of SnS thin films is the best at 400 ℃. Raman characteristic peaks of Sn S appear in Raman spectra of the thin films. While the increasing of the annealing temperature,the thickness of the films gradually decrease whereas the average particle sizes of the films increase. The absorption coefficient in the visible region is in the order of 105cm- 1at different thermal annealing temperature. The direct bandgap of the film is 1. 92 e V at 400 ℃. With the increasing of the thermal annealing temperature from 300 to 500 ℃,the resistivity of the films decreases from 1. 85 × 104 to 14. 97 Ω·cm.

Synthesis of SnO2@SnS2 core–shell nanorods by double crucible method and their photocatalysis

SnO2@SnS2 core–shell structural nanorods were prepared by the solid phase double crucible method. The structure, morphology and optical properties of the as-prepared samples were characterized by X-ray diffraction, transmission electron microscope and ultraviolet–visible–near-infrared spectrophotometer. The results indicated that the mixture of hexagonal phases SnS2 and tetragonal phase SnO2 was formed at 400 and 500 °C and the molar ratio of SnO2 to thioacetamide was 1:3. SnS2 was uniformly coated on the surface of SnO2 nanorods, and SnO2@SnS2 core–shell nanorods with the shell thickness of about 3–5 nm were obtained. Furthermore, their photocatalytic properties were tested for the degrading of methyl orange in water under visible light (λ > 420 nm) irradiation. Compared with pure SnS2 nanomaterials, the core–shell nanorods demonstrated more superior photocatalytic activity. These meaningful results had laid certain foundation for further research on metal oxide@metal sulfide core–shell structure nanomaterials.

Optical property of SmAlO3 applied as 1.06 μm laser absorbing material

SmAlO3 powders were successfully synthesized through the citrate sol-gel combustion method. The phase evolution of the prepared powders were characterized using thermal gravimetric (TG) analysis, differential scanning calorimetry (DSC) analysis and Fourier transform infrared spectroscopy (FTIR). X-ray diffraction (XRD) was applied to examine the purity of the powders. The reflective properties of SmAlO3 with changing temperatures were investigated by ultraviolet-visible near-infrared spectrophotometer (UVPC) specular reflection spectrum. The results displayed that pure SmAlO3 phase with preferable reflectivity at 1.06 μm could be obtained at 900 °C for 2 h. Furthermore, the reflectivity of SmAlO3 at various temperatures from −40 to 500 °C transformed within ±0.1%, and all maintained below 1% at 1.06 μm. The absorbance of SmAlO3 in the resin solution was 2.134 and the moral absorption coefficient was about 384.8 in the work. The study indicated that SmAlO3 powders may be a promising kind of heat resistant absorbing material for 1.06 μm laser defense, which could be further applied to laser absorbing coatings with a wide range of temperatures.

Preparation of single-layer antireflective SiO2 coating with broadband transmittance using PEG-modified sol–gel method

Adding polyethylene glycol (PEG) with different molecular weights, a usual acid-catalyzed sol–gel was modified to prepare single-layer antireflective SiO2 coatings with high and broadband transmittance and relatively better hardness. The test results of atomic force microscope and field emission scanning electron microscope show that the addition of PEG significantly affects the porosity and surface morphology of the coating layer. Due to the addition of PEG, the surface of the coatings presents groove-like and their porosity is increased, both of which contribute to the increase in transmittance. In the case of same PEG mass, PEG4000 modified coating has higher porosity and higher transmittance than PEG1000 modified one. In the present paper, the reflectance of samples for both sides was tested by ultraviolet–visible–near-infrared spectrophotometer (LAMBDA 950). The best coating’s reflectance can be decreased below 5 % from 460 to 1,740 nm. The transmittance peak value of the substrate is 90.6 % and its average value is 90.0 %, while the peak value of the best coating can reach up to 99.4 % and its average value is 95.5 % which increased by 5.5 % from wavelength of 325 to 1,000 nm. Hardness measurements show that the coatings have relatively better hardness.

Photocatalytic Activity of TiO&lt;SUB&gt;2&lt;/SUB&gt; Nanotubes Doped with Ag Nanoparticles

TiO2 nanotubes formed on the surface of commercially pure titanium were prepared by anodizing processing and were then heat-treated. The silver doping was processed with different molar concentration of AgNO3 aqueous solution. The silver-doped TiO2 nanotubes were characterized using field emission scanning electron microscopy, ultraviolet visible near-infrared spectrophotometer and ampere-volts (I-V) curve system. The 20-100 nm Ag nanoparticles were well doped atop, inside, and between the nanotubes. The I-V curve of the TiO2 nanotubes increased with heat treatment temperature. The silver-doped TiO2 nanotubes with anatase plus rutile phases had better photocatalytic activity.

Structural, morphological, and optical properties of TiO2 thin films synthesized by the electro phoretic deposition technique

In this work, we report the structural, morphological, and optical properties of TiO2 thin films synthesized by the electro phoretic deposition technique. The TiO2 film was formed on a doped fluorine tin oxide (SnO2:F, i.e., FTO) layer and used as a photo electrode in a dye solar cell (DSC). Using spectroscopic ellipsometry measurements in the 200 to 800 nm wavelengths domain, we obtain a thickness of the TiO2 film in the range of 70 to 80 nm. Characterizations by X-ray diffraction and atomic force microscopy (AFM) show a polycrystalline film. In addition, AFM investigation shows no cracks in the formed layer. Using an ultraviolet–visible near-infrared spectrophotometer, we found that the transmittance of the TiO2 film in the visible domain reaches 75%. From the measured current–voltage or I-V characteristic under AM1.5 illumination of the formed DSC, we obtain an open circuit voltage Voc = 628 mV and a short circuit current Isc = 22.6 μA, where the surface of the formed cell is 3.14 cm2.

Design and testing of a new high-accuracy ultraviolet–visible–near-infrared spectrophotometer

A new high-accuracy spectrophotometer has been developed at the National Research Council of Canada to measure regular transmittance factors over the spectral range from 200 to 2500 nm. The most significant feature of this automated single-beam instrument is a highly collimated normal-incidence beam geometry, which eliminates the need for polarization corrections or for an averaging sphere for the calibration of regular-transmittance reference materials. The instrument also possesses a large uniformmeasurement beam that minimizes errors caused by sample nonuniformity. We describe the instrument's design and the testing, optimization, and verification procedures that have been carried out for measurements in the visible and near-infrared regions. Systematic errors that have been determined and corrected for include wavelength shifts, stray light, system drift, and nonlinearity. In the visible and near-infrared regions, the overall photometric accuracy is estimated to be 2.5 and 4.0 parts in 10(4), respectively. The wavelength scale is accurate to within +/-0.1 nm with a reproducibility of +/-0.03 nm over its entire design range from 200 to 2500 nm.