Coated Indium Tin Oxide Research Articles

Fabrication of a highly sensitive conductive copolymer layer modified immunosensing tool for cytokeratin-19 fragment detection

Design of a new and highly selective impedimetric biosensor based on the immobilization of a fragment of cytokeratin subunit 19 (CYFRA 21-1)-specific antibodies onto a conductive copolymer layer (poly(epoxy-substituted thiophene)-co-poly(3,4-ethylenedioxythiophene), CCL)-coated indium tin oxide (ITO) for the determination of CYFRA 21-1 in serum samples was reported. CCL was applied as a working electrode-modifying reagent to prepare the surface of the working ITO electrode, and CYFRA 21-1-specific antibodies bound to epoxy ends present in the copolymer layer matrix. The impedimetric response of the immunosensor to CYFRA 21-1 was recorded, and the signaling mechanism of the suggested immunosensor was based on an increase in the charge transfer resistance in the presence of target CYFRA 21-1. The developed biosensor exhibited excellent selectivity for CYFRA 21-1, and it could detect CYFRA 21-1 in a linear dynamic range from 0.0125 to 35 pg/mL with a limit of quantification (LOQ) of 12.25 fg/mL. The designed biosensor showed good storage stability, high sensitivity, suitable repeatability and reproducibility, and acceptable long-term stability. The clinical analysis of the manufactured immunosensor was explored for the analysis of serum samples, and high recoveries and good relative standard deviations (RSDs) were obtained in the range of 97.01 and 103.17 %, respectively. This copolymer-based biosensor could be a feasible tool for clinical diagnosis in complex serum samples.

Preparation and performance of graphene-doped indium tin oxide coatings on titanium bipolar plate surface

To enhance the corrosion resistance of titanium bipolar plates, indium tin oxide (ITO) coatings doped with varying quantities of graphene were fabricated using the sol-gel method. The coatings' surface morphology and microstructure were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The hydrophobicity of the coatings was evaluated using a contact angle goniometer, and their corrosion resistance in a simulated proton exchange membrane fuel cell (PEMFC) corrosion solution (0.5 mol/L H2SO4 + 2 mg/L HF) was measured using an electrochemical workstation. The findings revealed that increasing graphene doping resulted in a more uniform, smooth, and dense coating surface. The ITO coating primarily consisted of In2O3. However, with graphene doping, diffraction peaks of the InOCl phase appeared, indicating changes in the material's composition and structure. Additionally, the valence peaks of the main elements shifted, reflecting alterations in their chemical states. Graphene doping significantly enhanced the coating's hydrophobicity compared to the undoped ITO coating. The water contact angle of the ITO coating with 0.375 g/L graphene increased from 104° to 126°. Furthermore, this graphene-doped coating demonstrated superior corrosion resistance, with a corrosion current density of 0.06 μA/cm2, representing a decrease by three orders of magnitude compared to the titanium substrate. Additionally, it exhibited the largest capacitive arc radius, indicating enhanced charge transfer resistance and better overall electrochemical stability.

Photoelectrochemical water oxidation reaction for coated and meta-chemical surface electrodes with Na3[Ru2(μ-CO3)4]

The most economical and efficient method to produce green hydrogen relies on electrochemistry, the electricity for which is of a green origin, and on photocatalytic water splitting. The latter technology involves the use of a photocatalyst or a photo-electrocatalyst to transform solar energy into chemical energy. Vast efforts have thus been dedicated to the pursuit of such a catalyst.The current study focused on the development of a heterogeneous photoelectrochemical system in which the Na3[Ru2(μ-CO3)4] complex was used as a WOC. To that end, two types of electrodes were prepared: coated indium tin oxide (ITO) and meta-chemical surface (MCS) electrodes. Under 420 nm illumination, both electrode types exhibited higher catalytic currents than were observed without light.Our novel application of the Na3[Ru2(μ-CO3)4] complex as a catalyst in the photoelectrochemical water oxidation reaction requires minute amounts of the complex. The study findings add to the knowledge about the water-splitting process, and ultimately, they may facilitate the broader adoption of hydrogen as an environmentally friendly and increasingly accessible energy source.

Fabrication and Characterization of Nanostructured Tin doped Indium Oxide Coatings by the Instrument of Spray Pyrolysis

Nanostructured indium tin oxide (ITO) coating is one of the transparent conductive oxides (TCO) materials utilized as a transparent electrode. Due to its high demand in various applications like liquid crystal displays, touch screens, light emitting devices, and solar cells, ITO coatings have garnered significant research attention, owing to their excellent properties of high visible light transmittance and low resistance. Nanostructured coating of tin -doped Indium Oxide (ITO) was fabricated on glass slides utilizing the instrument of chemical spray pyrolysis (CSP), with varying levels of Sn-doping at 0, 3, 6, and 9 wt%. The effect of tin content on the many physical characteristics of the resulting coatings has been examined. The analysis of x-ray diffraction (XRD) displayed the characteristic orientations. The coatings have a polycrystalline cubic lattice structure along (400) as the preferred growth direction. Morphological measurements indicate that the samples possess a highly uniform surface and the grain size for the ITO samples is 100 nm displaying a nanostructure for all samples. The optical transmittance was measured over 75% for coating with tin content equal to 0wt%, while the transmittance of the Sn-doped films can range from 78% to 84% at 700 nm and the values of the direct bandgap were measured as 3.6, 3.65, 3.675, and 3.7eV for Sn doping 0, 3, 6, and 9 wt% respectively. In the visible area, the nanostructured ITO coatings exhibit elevated values of transmittance which makes them suitable for various optoelectronic applications such as window materials in solar cells. The results indicate a desirable reduction in the electrical resistivity with rising the number of carriers per unit volume and mobility with increasing tin content in the samples. The minimum electrical resistivity and maximum carrier concentration were achieved for ITO coating with tin content equal to 9wt%. The incorporation of Sn dopant significantly changes the overall electrical properties of indium oxide films, this is favorable for transparent conducting oxide.

Designing surface microstructure for improving energy efficiency of SiO2 glass window by infrared emission

Windows are among the least energy-efficient components of buildings, accounting for about 44 % of building energy consumptions. Improving the energy efficiency of windows is crucial for sustainable and eco-friendly building design. In this work, we introduce a novel glass design featuring specialized surface structures on the front side and Indium Tin Oxide (ITO) coatings on the rear side. Through meticulous structural engineering, the front side achieves a high emissivity of approximately 0.97, ideal for efficient heat dissipation during the summer. Notably, our study reveals a myriad of possible configurations, offering great flexibility that is expected to ease the future fabrication process. Meanwhile, the back side exhibits a low emissivity of about 0.06 due to the ITO coatings, enabling heat retention in the winter. These innovative designs are expected to reduce the average energy consumption by more than 100 MJ/m2 per year. Our approach highlights the potential of mid-infrared emissions to enhance the energy efficiency of windows, thereby advancing the development of smart windows and optimizing their energy-saving capabilities.

Sustainable and Circular Management of Perovskite Solar Cells via Green Recycling of Electron Transport Layer‐Coated Transparent Conductive Oxide

AbstractTransparent conductive oxide (TCO)‐coated glasses are the most expensive and environmentally impacting components of perovskite solar cells (PSCs), comprising 56% of the total cost of a perovskite module and 96% of its carbon footprint. Thus, recycling TCO glasses from end‐of‐life perovskite modules can reduce both their levelized cost of electricity and energy payback time. In this work, tin oxide (SnO2)‐coated indium tin oxide glasses are refurbished from n‐i‐p PSCs employing dimethyl sulfoxide as a green solvent to dissolve the upper layers of the devices. Employing the recovered substrates, new‐generation PSCs are produced, which retain the same champion power conversion efficiency (PCE) of 22.6% as fresh samples and display an even higher average PCE. This performance enhancement is investigated through compositional and electrical analyses that demonstrate that the proposed recycling protocol induces beneficial surface modifications on the SnO2/perovskite interface and trap passivation, boosting charge extraction.

Investigation of IR Reflective Coating for Plexiglas Canopy

Purpose: Solar energy is necessary for our global ecosystem. In certain times and parts of the world, the heat generated from the energy of the Sun becomes uncomfortable for us and we need to use additional energy to cool down the generated heat from the Sun. This additional energy usage is detrimental to our environment due to generation of air pollution and use of our natural energy resources. The purpose of this paper is to investigate prevention of undesired generation of heat by the Sun using reflective coating materials.
 Methodology: In this study, using literature review, Ga doped Zinc Oxide (GZO) is theoretically investigated as a visible light transparent and infrared reflective coating material for the Plexiglas canopy of a solar car. The effect of doping concentration and film thickness is reviewed and discussed. Indium Tin Oxide (ITO) is also studied, using various literature reviews, as an infrared reflective coating material that is transparent in the visible light region. Finally, a spectrophotometer was used to examine the optical properties of a Plexiglas, slide glass, and ITO coated glass, and the results of UV and visible light transmittance measurement of the three materials is presented and discussed.
 Findings: GZO and ITO films both have high transparency in the visible region of the solar spectrum and high reflectivity to IR radiation starting from 1500 nm to higher wavelengths. None of these films completely reflect the IR radiation with wavelengths in the range of 700 nm to 1500 nm which contribute to generation of heat most. Many factors such as doping concentration and thickness of the films affect reflectivity of the films due to their effect on shifting the plasma frequency. Increasing doping concentration and thickness of the GZO films until a certain threshold improves IR reflectivity of GZO films, but it was not possible to precisely formulate these factors within this study. Reducing the particle size in nanoparticle ITO film improves transmittance of the film in the visible light region and its reflectance in the IR region. The measurement results showed that Plexiglas and glass have a high transparency to visible and near IR radiation.
 Recommendations: Further investigation and experimentation is recommended to fully understand and formulate doping concentration and film thickness of GZO and ITO to achieve optimal IR reflectivity within the 700 to 1500 nm wavelength region while maintaining visible light transparency. In regards to ITO coating, reduced nanoparticle size is recommended to improve the desired visible and IR transparency and reflectivity of the film. Although GZO and ITO coatings’ doping concentration and thickness to achieve IR reflectivity within the 700 to 1500 nm wavelengths is not well understood in this study, to reduce heat generation they are still recommended as a coating material due to their reflectivity to IR with wavelengths of above 1500 nm which also play a role in generation of heat.

The Influence of Thermal and Mechanical Stress on the Electrical Conductivity of ITO-Coated Polycarbonate Films.

The influence of thermomechanical stress on the conductivity of indium tin oxide (ITO)-coated polycarbonate (PC) films was investigated. PC is the industry's standard material for window panes. ITO coatings on polyethylene terephthalate (PET) films are the main commercially available option; as such, most investigations refer to this combination. The investigations in this study aim to investigate the critical crack initiation strain at different temperatures and crack initiation temperatures for two different coating thicknesses and for a commercially available PET/ITO film for validation purposes. Additionally, the cyclic load was investigated. The results show the comparatively sensitive behavior of the PC/ITO films, with a crack initiation strain at room temperature of 0.3-0.4% and critical temperatures of 58 °C and 83 °C, with high variation depending on the film's thickness. Under thermomechanical loading, the crack initiation strain decreases with increasing temperatures.

Functionalization of glass fiber woven fabrics by indium tin oxide (ITO) coatings for electromagnetic wave absorption

The effects of surface electrical conductivity and cascading order of ITO surface modified glass fiber woven fabrics (GFWF) on the electromagnetic (EM) behavior of hybrid type multilayered absorber structure were investigated. Additional objective was to create a design guideline for a multilayered absorbing structure according to the needs of specific EM wave absorber applications. For this purpose, indium tin oxide (ITO) sols were deposited on GFWFs by spray pyrolysis technique. The electrical conductivity of these conducting layers was controlled to incorporate EM wave absorbing characteristics to glass fabrics. Surface modified fabrics were then used as reinforcement in a hybrid type multilayered EM wave absorbing structure which is a combination of Jaumann and graded type absorbers effective in 8–12 GHz frequency range (X-band). The highest absorption performance design has been formed by cascading six ITO coated fabrics with gradually increasing electrical conductivity gradient from the front to back layer of the structure. The electromagnetic behavior of the multilayered absorber was tested both with and without metallic backing. The absorber design showed ∼−11 dB reflection loss and ∼−9 dB transmission loss corresponding to ∼80 % average absorption without metallic backing, while its reflection loss and average absorption values were ∼−10.5 dB and ∼93 %, respectively, with metallic backing. The front layer of the multilayered structure with the lowest surface electrical conductivity provided impedance matching between air and receiving surface of the structure minimizing reflection, where the gradual increase in surface conductivity of the layers towards the back provided balanced internal reflection and transmission leading to high overall EM wave absorption. Consequently, by controlling the grading of the surface conductivity of the layers through the thickness, responses of the absorbers can be adjusted to provide tailored characteristics for the required EM wave absorption levels.

Nanopatterned indium tin oxide as a selective coating for solar thermal applications

Indium tin oxide (ITO) coatings have been proposed to reduce thermal emission losses for solar thermal applications. Unfortunately, ITO also has a large amount of free charge carriers (∼1 × 1020 per cm3), which absorb sunlight. To address this issue, we propose a nano-patterned ITO-coated quartz exhibiting both anti-reflectivity (to maximize solar transmission) and low emissivity (to minimize long wavelengths radiative losses). A record small-size nanosphere (∼60 nm) etch mask was prepared via double self-assembly, followed by dry etching and characterisation. In parallel, alternative nanopattern geometries were modelled using the Lumerical FDTD software to optimise short wavelength transmission without diminishing the inherently low emissivity of unetched ITO. It was found that an inverted moth's eye pattern (height = 250 nm and spacing = 80 nm) gave the best results at various solar concentrations (1 sun @ 100 °C, 10 suns @ 400 °C, and 100 suns @ 600 °C), resulting in ∼7% improvement in the solar weighted transmission as well as a similar boost in the overall efficiency factor for selectivity. It was concluded that if the proposed deposition/etching processes can be cost-effectively scaled in a continuous process, it would provide a net performance boost for most solar thermal technologies.

Symmetric and Asymmetric Supercapacitors of ITO Glass and Film Electrodes Consisting of Carbon Dot and Magnetite

To enhance the energy density, hybrid supercapacitors were fabricated, and their electrochemical features were investigated using a two-electrode configuration. By assembling nitrogen-doped graphene/magnetite (NG/Fe3O4) on indium tin oxide-coated (ITO) glass as a cathode and NG/carbon dots(Cdots)/Fe3O4 on ITO glass as an anode, a much higher gravimetric specific capacitance of 252.2 F/g, at a current density of 0.5 A/g, was obtained from this asymmetric supercapacitor compared with that (212.0 F/g) of a symmetric supercapacitor (NG/Cdots/Fe3O4)//(NG/Cdots/Fe3O4). A gravimetric energy density of 90.1 Wh/kg was obtained for an asymmetric ITO glass device at a specific power density of 400.0 W/kg. On the other hand, when an asymmetric two-electrode cell was fabricated with a Cdots/polypyrrole (PPy)/Fe3O4/TEMPO-oxidized cellulose nanofiber (TOCNF)-film electrode and a Cdots/PPy/TOCNF-film electrode, the specific capacitance (107.1 F/g) at a current density of 0.8 A/g was lower than that (456.4 F/g) of a symmetric (Cdots/PPy/Fe3O4/TOCNF)//(Cdots/PPy/Fe3O4/TOCNF)-film cell. Subsequently, a gravimetric energy density of 40.6 Wh/kg was achieved for a symmetric-film device at a specific power density of 320 W/kg. These results suggest that our method offers an efficient approach to developing symmetric and asymmetric devices consisting of hybrid materials for meeting the ever-increasing demands on energy-storage devices.

Pd nanocatalysts adsorbed onto silica nanoparticle coated indium tin oxide: a reusable nanozyme for glucose detection.

Nanozymes are nanomaterials that exhibit enzyme-like activity upon exposure to a substrate solution. The use of noble and platinum group metals enhances enzyme-like catalytic activity. However, noble metals are obtained at a high cost; therefore, their recovery after use is of high importance. Herein, we report the fabrication of indium tin oxide-silica nanoparticles decorated with palladium nanoparticles (ITO-SiO2-prS-PdNPs). The ITO-SiO2-prS-PdNPs were evaluated for peroxidase-like activity toward the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2. A colour change from clear or colourless TMB to blue colour (oxidized TMB products) was observed confirming the peroxidase-like activity. A typical Michaelis-Menten enzyme-like behaviour is observed with Km values of 0.68 mM for H2O2 and 0.47 mM for TMB, which are better than the reported values for horse-radish peroxidase (HRP) for the same substrate. The peroxidase-like activity of ITO-SiO2-prS-PdNPs was found to proceed via the electron-transfer mechanism. The ITO-SiO2-prS-PdNPs were cleaned successfully after each use by rinsing with water and ethanol solution thus making the surface simple and easy to recover and reuse. A reusable and highly selective colorimetric assay for glucose detection based on the peroxidase-like activity of ITO-SiO2-prS-PdNPs gave excellent results. ITO-SiO2-prS-PdNPs exhibited a good linear range of 5.0-30 μM, a low limit of detection (LOD) of 1.84 μM and a limit of quantification (LOQ) of 6.14 μM. Finally, the nanozyme (ITO-SiO2-prS-PdNPs) was successfully used to detect glucose in a complex newborn calf serum (NCS), representing a real sample.

Synthesis of Conjugated bis-Schiff Base and Their Complexes as Dye-Sensitizer for Dye Sensitized Solar Cell (DSSC) Application

Schiff base and their metal complexes have been widely used as photovoltaic materials due to their excellent π-electron transfer properties along the molecule. A total of eleven conjugated symmetrical bis-Schiff base and their complexes with different π-spacers have been synthesized and spectroscopically characterized in order to investigate their conversion efficiency in dye-sensitizer solar cells (DSSC). All compounds were either substituted with hydroxy (-OH) or methoxy (-OMe) as the electron donor and difluoro boron (BF2) as the electron acceptor or without any substituent. All compounds were applied as dye-sensitizer in DSSC using titanium (IV) oxide (TiO2) coated on a fluoride doped tin oxide glass as the working electrode and electric paint containing carbon black, whereas graphene coated indium tin oxide glass as the counter electrode. The power conversion efficiencies of the eleven bis-Schiff bases were compared to N3 Dye as the benchmark standard. The results showed that the compound with aromatic ring bridge as the π-spacer and -OMe substituent gave the highest efficiency at 0.0691% whereas the compound with aromatic ring and BF2 gave the lowest efficiency at 0.0012%.

Electrochemical detection of cystatin C by oriented antibody immobilization on streptococcal protein G–modified ZIF-8-Cu1−xNix(OH)2@Cu core-shell nanostructured electrode

Herein, we prepared a novel nanostructure involving Cu shell on Zeolitic imidazolate frameworks (ZIF-8) and Cu1−xNix(OH)2 composite (ZIF-8-Cu1−xNix(OH)2@Cu) combining sol-gel and co-precipitation method. The morphology, stoichiometry, and structure of the nanocomposite were elucidated by various physicochemical analyses. A poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) coated indium tin oxide (ITO) was modified with the synthesized ZIF-8-Cu1−xNix(OH)2@Cu nanoparticles (NPs) to obtain an efficient electrode for further antibody immobilization. The ZIF-8-Cu1−xNix(OH)2@Cu/PEDOT:PSS/ITO was applied for the detection of cystatin C, a promising biomarker of chronic kidney disease (CKD). The electrode was functionalized by streptococcal protein G (SPG) to bind the Fc region of anti-cystatin C in an oriented manner. The synergistic catalytic activities, high surface coverage, enhanced electroactive sites, and excellent redox properties of the proposed electrode lead to excellent electrochemical sensing. The proposed sensor obtained a much lower detection limit (33 pg/mL) for a linear range of 0.1 ng/mL to 1,000 ng/mL with high selectivity, stability, and reproducibility compared with bare ZIF-8/PEDOT:PSS/ITO-based immunosensor. The clinical feasibility of the sensor was confirmed by measuring the human serum in the presence of different concentrations of cystatin C. This work demonstrates a new and facile approach to fabricating a metal-organic framework (MOF) –based nanoimmunosensor for cystatin C, which has significant importance in diagnosing the renal failure.

Growth of single-crystalline MAPbI3 perovskite film by a modified space-confined inverse temperature crystallization method

Single crystalline (SC) metal halide perovskite absorber film can outperform its polycrystalline counterpart in power conversion efficiency and stability due to the absence of grain boundaries. However, SC perovskite film's direct growth on charge selective contact layer coated substrates for solar cell applications is not widely explored. In this study, SC methylammonium lead iodide (MAPbI3) perovskite film is directly grown on charge selective (electron and hole transport) contact layer coated substrates (TiO2 coated fluorine doped tin oxide (FTO) glass substrate and poly(triarylamine) (PTAA) coated indium tin oxide (ITO) glass substrate) by inverse temperature crystallization (ITC) method. The PTAA/ITO substrate's hydrophobic nature led to faster ion migration and controlled nucleation, resulting in large-sized SC MAPbI3 perovskite film. X-ray diffraction of the MAPbI3/PTAA/ITO showed SC nature with diffraction from (200) and (400) planes, indicating that the film is majorly (100) oriented. The MAPbI3 film grown on TiO2/FTO is found to be relatively small in size (< 1 mm), majorly oriented in the (110) plane with diffraction also from other planes indicating polycrystalline nature. Long-term stability studies over 1500 h show that SC MAPbI3 films show more endurance to ambient conditions than polycrystalline MAPbI3. The growth time of 50 h was reduced to 30 h by employing antisolvent-assisted ITC, resulting in ultra-stable circular shaped films suitable for photovoltaic applications.

The effect of indium–tin oxide coatings on the formation of craters on glass surfaces under the impact of high-velocity microparticles

This article considers the problem of improved mechanical properties and protection of glass materials in optical systems of space vehicles. One the possible methods to solve the problem is the formation of multi-phase nanocomposite shock-resistant transparent coatings on the surface of glass plates. Considerable attention is paid to the application of indium–tin oxide (ITO) coatings on the surface of quartz glass pieces deposited by the method of pulsed magnetron sputtering. Such coatings demonstrate the highest properties. The optical characteristics of ITO coatings were studied in a range of wavelengths of 200–1100 nm. It was shown that in the visible spectrum they remain transparent. The structure and phase composition of indium tin oxide coating, basically, contains nanocrystalline In2O3 phase, which is indicated by the diffraction reflexes on obtained electron diffraction patterns and X-ray diagrams.It was unveiled that the deposited ITO-based coatings possess resistance to the shock impact of hyper-velocity iron microparticles. They can appreciably reduce surface density of the craters formed on the surface of glass plates under the impacts of solid microparticles due to increased strength and cracking resistance of the glass specimens. The character of alteration of the crater density of the glass surface with the coating is explained by the superposition of two mechanisms: reinforcement of the surface layer of glass due to deposited nanocomposite coating and supplementary dissipation of the energy of the normal shock wave that excites generation and propagation of secondary surface waves at the interface of heterogeneous layers of the ceramic coating and quartz.

ZIF-8 Nanoparticles Based Electrochemical Sensor for Non-Enzymatic Creatinine Detection.

There is a consistent demand for developing highly sensitive, stable, cost-effective, and easy-to-fabricate creatinine sensors as creatinine is a reliable indicator of kidney and muscle-related disorders. Herein, we reported a highly sensitive and selective non-enzymatic electrochemical creatinine sensor via modifying poly(3,4 ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) coated indium tin oxide (ITO) substrate by zeolitic imidazolate framework-8 nanoparticles (ZIF-8 NPs). The topography, crystallinity, and composition of the sensing electrode were characterized by field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The peroxidase-like activity of ZIF-8 nanoparticles enabled it to detect creatinine forming a zinc-creatinine composite. The electrochemical behavior and sensing performance were evaluated by amperometric and impedimetric analysis. The sensor obtained a sufficiently low limit of detection (LOD) of 30 µM in a clinically acceptable linear range (0.05 mM–2.5 mM). The interference study demonstrated high selectivity of the sensor for creatinine concerning other similar biomolecules. The sensing performance of the creatinine sensor was verified in the actual human serum, which showed excellent recovery rates. Hence, the magnificent performance of ZIF-8 based non-enzymatic creatinine sensor validated it as a responsible entity for other complicated renal markers detection.

Influence of electrochemical co-deposition of bimetallic Pt–Pd nanoclusters on polypyrrole modified ITO for enhanced oxidation of 4-(hydroxymethyl) pyridine

Bimetallic Pt–Pd nanoparticles were dispersed on polypyrrole coated indium-tin oxide coated polyethylene terephthalate sheets (ITO-PET sheets). The excellent filming property of pyrrole gives a high porous uniform active area for the proper adsorption of bimetallic transition metal nanoparticles. Electrochemical behavior of the modified electrodes was determined using cyclic voltammetry and impedance studies. The physicochemical properties of the modified electrodes were analyzed by scanning electron microscopy, X-ray diffraction spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. To study the electrochemical oxidation of 4-(hydroxymethyl) pyridine in the presence of sodium nitrate in aqueous acidic medium, the modified electrode was used. It is evident from the study that the modified electrode shows better electrochemical activity towards the oxidation of 4-(hydroxymethyl) pyridine.

Application of Pyroelectric Sensors Based on PVDF Films for EPR Spectra Detection by Heat Release.

Pyroelectrics are a wide class of materials that change their polarization when the system temperature varies. This effect is utilized for a number of different commercial and industrial applications ranging from simple thermal sensors and laser interferometers to water vapor harvesting. Electron paramagnetic resonance (EPR) spectroscopy is a powerful tool for studying the structure and dynamics of materials with unpaired electrons. Since heating accompanies a resonant change of the orientation of electron spins in an external magnetic field, pyroelectrics can be utilized as versatile detectors for so-called indirect detection of the EPR signal. In this work, we investigated three different types of PVDF (polyvinylidene difluoride) standard pyroelectric films with indium tin oxide, Cu/Ni, and Au coatings to determine their sensitivity for detecting EPR signals. All the films were shown to be able to detect the EPR spectra of about 1 μg of a standard stable free radical by heat release. A comparative study based on the calculation of the noise-equivalent power and specific detectivity from experimental spectra showed that the Au coated PVDF film is the most promising active element for measuring the EPR signal. Using the best achieved sensitivity, estimation is given whether this is sufficient for using a PVDF-based pyrodetector for indirectly detecting EPR spectra by recombination heat release or not.

Characterization and Optimization of AZO Nanoparticles as Coatings for Flexible Substrates toward High IR Reflectivity.

Energy consumption by air-conditioning is expansive and leads to the emission of millions of tons of CO2 every year. A promising approach to circumvent this problem is the reflection of solar radiation: Rooms that would not heat up by irradiation will not need to be cooled down. Especially, transparent conductive metal oxides exhibit high infrared (IR) reflectivity and are commonly applied as low-emissivity coatings (low-e coatings). Indium tin oxide (ITO) coatings are the state-of-the-art application, though indium is a rare and expensive resource. This work demonstrates that aluminum-doped zinc oxide (AZO) can be a suitable alternative to ITO for IR-reflection applications. AZO synthesized here exhibits better emissivity to be used as roofing membrane coatings for buildings in comparison to commercially available ITO coatings. AZO particles forming the reflective coating are generated via solvothermal synthesis routes and obtain high conductivity and IR reflectivity without the need of any further post-thermal treatment. Different synthesis parameters were studied, and their effects on both conductive and optical properties of the AZO nanoparticles were evaluated. To this end, a series of characterization methods, especially 27Al-nuclear magnetic resonance spectroscopy (27Al-NMR) analysis, have been conducted for a deeper insight into the particles' structure to understand the differences in conductivity and optical properties. The optimized AZO nanoparticles were coated on flexible transparent textile-based roofing membranes and tested as low-e coatings. The membranes demonstrated higher thermal reflectance compared with commercial ITO materials with an emissivity value lowered by 16%.