Chemical Deposition Method Research Articles

Convolutional Neural Networks for Predicting Morphological and Nonlinear Optical Properties of Thin Films of Quasi-Two-Dimensional Materials

Two-dimensional materials are promising candidates for the creation of flat photonics devices. The main problem of using such materials for applied applications is the complexity of creating films of specified geometric parameters. The films of two-dimensional materials made by exfoliation or chemical deposition methods are usually randomly distributed over a large area and have a large thickness spread. In this paper, we use convolutional neural networks to predict the film thickness of a quasi-two-dimensional material based on optical microscopy data. Hexagonal boron nitride, which is actively used in the creation of flat electronic and optoelectronic devices, was chosen as a test material. Due to the high spatial resolution of microscopy, it is possible to achieve high accuracy in predicting the thicknesses of flat areas of the sample, which allows for rapid characterization of structures. In addition, using the example of the signal of the third optical harmonic, we show the possibility of predicting the magnitude of the nonlinear optical response of the film, which expands the scope of the method.

Magnetic field assisted chemical deposition synthesis of leaf-like Co3O4 nanostructure for supercapacitor electrode

A novel leaf-like cobalt oxide particles were prepared by a magnetic field assisted chemical deposition method and subsequently sintering process. The phase structure, morphological changes, and electrochemical performance of the cobalt oxide particles were systematically tested and the effect of the magnetic field on the product morphology was studied. Owin to the unique leaf-like shape structure, the optimal Co3O4 particles at 80 mT displayed the highest specific capacitance of 1247.4 Fg−1 at 1 A/g, with a retention rate of 94.1 % after 10,000 cycles.

Characterization Mass Ratio of TiO2: Coconut Shell Using FTIR analysis as a Super capacitor

The aim of this research is to determine the characteristics of the mass ratio of TiO2 to activated coconut shell. This research was carried out using a chemical deposition method which utilized H2SO4 as the reagent. Next is the activation of carbon which will later be used as supercapacitor material. Based on the objectives and methods carried out, the results obtained were that the mass ratio was 1:1, visible in the spectrum at wavelengths of 940 cm-1, 1037 cm-1, 1623 cm-1, and 2958 cm-1. Based on the spectrum at conditions 940-1037 cm-1, there are indications of the formation of C-C groups, in this condition carbonization is formed. At a mass ratio of 1:3 there is a wave shift starting at 884 cm-1 and the largest shift at a wave number of 2950 cm-1. In this comparison, O-H groups or carboxylic acids were still found. At a mass ratio of 1:5 the wave number shift starts at 884 cm-1, 1135 cm-1, 1635 cm-1 and 2362 cm-1. Based on the wave number 884-1135 cm-1, the functional group formed is the C-C bond, apart from that, the wavelength area of 1635 cm-1 shows the presence of the C=C bond

Optical Properties of (CuFe(1-x) CrxO4) Nanostructures Prepared by Chemical Deposition Method

Thin films of (CuFe(1-x) CrxO4) with weight ratios (x = 0, 0.2, 0.4, 0.6, 0.8, 1) were prepared using the chemical deposition method on glass bases with dimensions x 1cm (1cm) at (700°C) temperature. Studying the optical properties of the prepared films includes recording the absorbance spectrum and the optical energy gap for the wavelength range (300-900 nm). Moreover, studying the optical constants is represented by the extinction coefficient, the refractive index, and the real and imaginary part of the dielectric constant as a function of wavelength. The optical properties show the appearance of a peak, an absorbance at a wavelength of 370 nm when adding a chromium ion as a substitute for the iron ion. The intensity of this peak increases directly with the increase in the percentage of chromium in the sample. It was also observed that the energy gap decreases significantly to 3eV. There is a slight increase in the value of the optical energy gap to 3.1eV when the percentage increases to x=0.8 due to decrease in size.

Exploring the structural, optical, and optoelectrical characteristics of p-type CuNiBiS3 thin films prepared by the chemical deposition method

Exploring the structural, optical, and optoelectrical characteristics of p-type CuNiBiS3 thin films prepared by the chemical deposition method

CeVO4/C-decorated carbon fiber cloth as carbon fiber-supported membrane catalyst to activate peroxymonosulfate for tetracycline removal

The powder shape of a catalyst limits its practical applications in advanced oxidation processes. Herein, we used carbon fiber cloth (CFC) as a flexible matrix and introduced a carbon layer on its surface (c-CFC). CeVO4 nanoparticles were synthesized on the c-CFC surface using a chemical deposition method, successfully fabricating a CeVO4/c-CFC carbon fiber-supported membrane catalyst for peroxymonosulfate (PMS) activation. The results indicate that CeVO4/c-CFC (2 × 2 cm2) has excellent reusability and can efficiently remove 97% of tetracycline (TC) within 15 min. The interaction between CeVO4 and CFC provides abundant active sites, and promotes electron transfer. Furthermore, the carbon layer modification enhances the interfacial contact and electrochemical performance. In addition, hydroxyl radicals, sulfate radicals, and singlet oxygen species are also involved in TC degradation. Finally, the unique membrane shape endows the catalyst with easy recyclability and low environmental toxicity in practical applications.

Synthesis of High Sn Content Ge1-x-ySixSny (0.1 < y < 0.22) Semiconductors on Si for MWIR Direct Band Gap Applications.

A systematic effort has been described to grow ternary Ge1-x-ySixSny semiconductors on silicon with high Sn concentrations spanning the 9.5-21.2% range. The ultimate goal is not only to produce direct band gap materials well into the infrared region of the spectrum but also to approach a critical concentration (yc) for which further additions of Si would decrease─rather than increase─the band gap. This counterintuitive behavior is expected as a result of the giant bowing parameter in the compositional dependence of the band gap associated with the presence of Si-Sn pairs. The growth approach in this study was based on a chemical vacuum deposition method that uses Si4H10, Ge3H8, and SnD4 or SnH4 as the sources of Si, Ge, and Sn, respectively. A fixed Si concentration near x = 0.05-0.07 was chosen to focus the exploration of the compositional space. A first family of samples was grown of Ge-buffered Si substrates. For Sn concentrations y < 0.12, it was found that the samples relaxed their mismatch strain in situ during growth, resulting in high Sn content films that had relatively low levels of strain and exhibited photoluminescence signals that demonstrated direct band gap behavior for the first time. The device potential of these materials was also demonstrated by fabricating a prototype photodiode with low dark currents. The optical studies suggest that the above-mentioned critical concentration is close to yc = 0.2. As the growth temperature was lowered in an effort to reach such values, Sn concentrations as high as y = 0.15 were obtained, but the films grew fully strained with compressive levels as high as 1.7%. To increase the Sn concentration beyond y = 0.15, a new strategy was adopted, in which the Ge buffer layer was eliminated, and the ternary alloy was grown directly on Si. The much higher lattice mismatch between the Ge1-x-ySixSny layer and the Si substrate caused strain relaxation right at the film/substrate interface, and the subsequent films grew with much lower levels of strain. This made it possible to lower the growth temperatures even further and achieve a comprehensive series of strained relaxed samples with tunable Sn concentrations as high as y = 0.21 (and beyond). The latter represent the highest Sn contents in crystalline Ge1-x-ySixSny attained to date and reach the desired yc = 0.2 range. The synthesized films exhibited significant thickness, allowing a thorough determination of composition, crystallinity, morphology, and bonding properties, indicating the formation of single-phase single-crystal alloys with random cubic structures. Further work will focus on optimizing the latter samples to explore the optical and electronic properties.

CoFe2O4 deposited on the rice husk-derived cordyceps-like SiC as an effective electrocatalyst for overall water splitting

Electrocatalytic water splitting typically requires higher energy consumption. Coupling transition metals with other conductive materials is an effective strategy for reducing energy consumption. Herein, a chemical deposition method, which is both uncomplicated and efficient was devised for the preparation of non-precious metal/rice hull-based Si-carbon composite bifunctional electrocatalyst. The CoFe2O4 nanoparticles were uniformly deposited on SiC with a Cordyceps-like structure by coupling chemical deposition with carbonization. The specific structures and surface metal active sites enhance the electrical conductivity of the samples. The bifunctional catalyst (Fe/Co-RHC-500) exhibited impressive performance, HER and OER showed low overpotentials of 151 and 190 mV at a current density of 10 mA·cm-2 as well as Tafel slopes of 63.4 and 33.3 mV dec-1, respectively. When used as the cathode and anode for water electrolysis, it achieved a current density of 10 mA cm−2 at a voltage of 1.63 V. The results demonstrate that Fe/Co-RHC-500 sample is a promising candidate for bifunctional catalyst materials. This work broadens the potential application of biomass waste in electrocatalytic splitting of water.

Design of Ag@ZnO@Ti3C2 MXene heterojunction photocatalyst for enhanced photocatalytic degradation activity of methylene blue and levofloxacin under visible light irradiation

A ternary Ag@ZnO@Ti3C2 MXene heterojunction (AZM) is synthesized by hybridizing ZnO and Ag nanoparticles with the MXene via a simple hydrothermal and chemical deposition method. The addition of ZnO and Ag can effectively compensate for MXene’s narrow bandgap property, promote charge carrier separation, and improve visible light absorption, thereby enhancing photocatalytic activity. The photocatalytic activity of the AZM is evaluated through the removal efficiency of methylene blue (MB) dye and levofloxacin (LVX) under visible light irradiation. The results show that the optimized ternary AZM heterojunction photocatalysts (AZM-15) possesses the maximum degradation of MB (90.54%) with a reaction rate constant of 0.0473 min−1, while the maximum degradation of LVX (86.76%) has a reaction rate constant of 0.0408 min−1. Moreover, the AZM composite exhibits excellent stability, which explains its MB removal rate of 83.59% and LVX removal rate of 80.03% after five cycles. The results of trapping experiments and EPR demonstrated that the main active species in the MB and LVX photodegradation process are·OH and·O2-. This work not only elucidates a possible mechanism of photocatalytic degradation of organic pollutants but also provides a pathway to design new bandgap photocatalysts for mitigating environmental pollution.

Stable zinc anode interface and environmentally adaptable hydrogel electrolytes for stable operation of zinc-ion hybrid supercapacitors

Hydrogel-based zinc ion hybrid supercapacitors (ZIHS) have stood out from many energy storage device candidates due to their battery-level energy density, inherent flexibility, and safety. Nevertheless, the inevitable dendrite growth of Zn anodes and sharp capacity degradation at low-temperature seriously hinder their practical application. Herein, a dense ZnF2 solid electrolyte interface protective layer was constructed in situ on the Zn electrode surface by a simple chemical deposition method, effectively isolating the water molecules and alleviating the water-induced dendrite growth and parasitic reaction. To achieve the flexible ZIHS with environmental adaptability, a self-adhesion and anti-freezing zwitterionic hydrogel electrolyte was fabricated to afford superior ionic conductivity (97.1 mS cm−1), excellent anti-drying ability, and robust interfacial adhesion. Benefitting from the integrated merits of the as-designed electrolyte and electrode, the ZIHS delivered excellent mechanical adaptability, favorable energy density (103.9 Wh kg−1 at 270.1 W kg−1), broad operating temperature range (−40 to 40 °C), along with long-term cycling stability (12,000 cycles) with 90.3 % capacity retention at −25 °C. Notably, the unencapsulated ZIHS achieved exceptional electrochemical stability in an open environment. This finding provides valuable insights for constructing durable, flexible, and environmentally adaptable zinc-based energy storage systems.

Core-shell structured Co(OH)F@FeOOH enables highly efficient overall water splitting in alkaline electrolyte

Constructing a low-cost, high activity and stable electrocatalyst for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) via overall water splitting is of great significance, but remains a big challenge. In this work, vertically aligned core-shell Co(OH)F@FeOOH nanorod arrays (NRs) on Ni foam were constructed via hydrothermal and chemical deposition methods. Due to the synergistic effects and electron interaction at the interface between Co(OH)F and FeOOH, the synthesized core-shell Co(OH)F@FeOOH heterostructure exhibits remarkable OER and HER catalytic activity in 1 M KOH solution, presenting low overpotentials of approximately 205 mV and 137 mV at a current density of 10 mA cm−2, and low Tafel slopes of approximately 48 mV dec−1 and 86 mV dec−1, for OER and HER, respectively. Moreover, the synthesized Co(OH)F@FeOOH serves as a bifunctional electrocatalyst for overall water splitting and it only needs 1.55 V to drive the electrolysis cell yielding 10 mA cm−2 which is much lower than that of 1.68 V for IrO2||Pt/C and showing excellent stability for 37 h. The prepared Co(OH)F@FeOOH catalyst has been successfully used in solar cell-driven water electrolysis, demonstrating its great potential for cost-effective electrochemical hydrogen production.

Heterostructures Based on Noble Metal Films with Ag and Au Nanoparticles: Fabrication, Study of In Vivo Biocompatibility and Antibacterial Activity

In this work, approaches to the formation of multifunctional film heterostructures based on noble metals for the modification of the surface of implant materials (titanium alloy TiAl6V4 and carbon-fiber-reinforced polyetheretherketone CFR-PEEK) are developed. Such heterostructures consist of continuous layers of platinum (Pt) or iridium (Ir) and antibacterial components on their surface, namely silver (nanoparticles or discontinuous films) and gold (nanoparticles). Chemical or physical gas-phase deposition methods were used for their preparation. The influence of the concentration and form of the antibacterial component on the antibacterial activity and in vivo biocompatibility of the film structures was evaluated for the first time. Differences in the dynamics of silver dissolution depending on Ag concentration in the sample and the type of bottom surface (the noble metal layer = Ir, Pt or TiAl6V4) surfaces allowed us to better understand the nature of the antibacterial action against Staphylococcus aureus and Pseudomonas aeruginosa (S. aureus and P. aeruginosa) of Ag/M heterostructures. From in vivo histological studies using rats, the best biocompatibility was shown by the Ag/M heterostructure with a prolonged release of the low fraction of antibacterial component (Ag).

Sb2Se3 thin films: A brief review of recent developments

This paper presents the preparation synthesis of p-type Sb2Se3 films on to various substrates (microscope glass, molybdenum coated glass, fluorine-doped tin oxide glass, and mica) via chemical deposition methods and physical deposition techniques. The properties of the obtained films have been studied by using different tools (x-ray photo electron spectroscopy, x-ray diffraction, atomic force microscopy, high-resolution transmission electron microscopy, Rutherford back scattering, scanning electron microscopy, Raman spectroscopy, energy dispersive x-ray analysis). Thin films showed unique physical, optical, and electoral properties, and have found application in the solar cells (power conversion efficiency in the range of 1.9%-10.57%). X-ray diffraction studies confirmed polycrystalline with orthorhombic phase. Optical studies indicated the band gap in the range of 1.03 eV to 1.85 eV.

A Review Paper on “Vanta-black Color”, “Reinforced Polymer Based Materials/ Radar Absorbing Materials”&amp; “Thermal Infrared Reflective Metal Oxide Sol-gel Coating” Used in “Stealth Vehicle”

Every country is doing a lot of research and development work on security and defense. A country like India shares their border with different countries from three sides need a lot of protection on border. Countries are making new armors and weapons with latest technologies so that their border can be protected. With the help of stealth technology, we make any object similar to surrounding environment in term of color (vantablack) and shape. If we use this technology in army jeep and tanks, then enemy will not be able to find out the position of our jeep and tanks on border. Stealth vehicle will be very useful from defense point of view on border. To make the vehicle stealth, we will give a new design to the vehicle, do thermal infrared reflective coating on engine and used super alloy to make the body of the vehicle. By applying thermal infrared reflective coating on vehicle, the vehicle will not emit heat and any heat sensor will not be able to detect the position of the vehicle. Thermal infrared reflective coating will act as heat insulator and will not allow heat to escape from the engine and vehicle body. We will use advanced cooling system to keep the engine temperature under control. The enemy army uses a heat sensor device to detect the vehicle’s position and when the vehicle does not emit heat, the sensor device will become useless. We see the use of thermal barrier coating in aerospace industry where thermal barrier coating applied on engine turbines. Thermal barrier coating concept is similar as Thermal infrared reflective coating. Thermal infrared reflective coatings have anti corrosive properties as well as with stand on high temperature up to 1100⁰C. Thermal expansion that occurs in the turbine blade due to high temperature does not degrade the thermal infrared reflective coating. The outer surface of Aircraft is also an example of high quality thermal infrared reflective coating. The most commonly used thermal infrared reflective coating material is Ferromagnetic Oxide which has extremely high resistance against thermal shock up to 1100⁰C. Ferro-magnetic Oxide increases the durability of thermal infrared reflective coating and it is a rare earth element. Metal Oxide is generally applied on the material as thermal infrared reflective coating by the process of chemical deposition method and physical vapor deposition (diffusion coating methods).

Fully Inkjet‐Printed Perovskite Microlaser with an Outcoupling Waveguide

AbstractPhotonic materials based on metal halide perovskites undergo rapid development owing to their unique optical properties and facile synthesis. Concurrently, there is also a growing interest in integrated photonics that can combine several elements on one chip. Nowadays technologies of integrated photonics are based on the traditional mask lithography combined with physical or chemical deposition methods. In this study, the possibility of facile fabrication of a simple pair of photonic elements is addressed, such as a microresonator with an outcoupling waveguide by means of inkjet printing on a glass substrate covered by a layer of polydimethylsiloxane (PDMS). The printed laser has revealed an appreciably high laser emission with a Q‐factor of 3300 and a threshold excitation fluence of 34 µJ·cm−2. The outcoupling waveguide has demonstrated the capability to transfer a reasonable part of the emitted radiation. The experimental results with a numerical simulation based on an appropriate physical model are also rationalized. Thus, the study points out a perspective for integrated photonics to be possibly implemented with this relatively cheap, flexible, and scalable fabrication method.

Memory properties and short-range order in silicon oxynitride-based memristors

Silicon oxynitride films of various compositions were grown by the plasma-enhanced chemical deposition method using a setup with remote plasma and an inductive excitation from a gas mixture of 10% monosilane (diluted with argon) and nitrogen in the presence of residual oxygen in working gas mixtures. The high-frequency generator power (13.56 MHz) was varied in the range of 50–150 W. The samples composition was studied using x-ray photoelectron spectroscopy. A comparison of the experimental Si 2p photoelectron spectrum with the calculation showed that, at a low generator power (50 W), the short-range order in silicon oxynitride films is better described by the “random mixture” model. As the generator power is increased (100 W and higher), the excess silicon content in a silicon oxynitride film is decreased, and the short-range order is better described by the “random bonding” model. On metal–insulator–semiconductor-structures based on the silicon oxynitride films obtained, measurements of current–voltage characteristics were carried out, and the resistive switching of the obtained structures is studied in the present contribution. It is found that, in films in which the short-range order is described by the random bonding model, a stable switching in the bipolar regime is observed.

Fabrication of plane-type axon guidance substrates by applying diamond-like carbon thin film deposition

This research aims to fabricate plane-type substrates for evaluating the axon behaviors of neuronal cells in vitro toward the development of brain-on-chip models by applying the functions of diamond-like carbon (DLC) thin film deposition, which helped to eliminate the costly and time-consuming lithography process by utilizing a shadow mask. The DLC thin films were partially deposited on stretched polydimethylsiloxane (PDMS) substrates covered with a metal mask by the plasma chemical vaper deposition method, and using the substrates culture teats with human neuroblastoma cells (SH-SY5Y) were performed. Three patterns of interconnection structures of axons were created on the substrates with disordered and regular linear wrinkle structures with several μm size formed by the depositions. The patterns were characterized by the structure that the aggregations of axons formed on the linear DLC thin film deposited areas were separately placed in regular intervals and connected each other by plenty of axons, which were individually taut in a straight line at about 100 to over 200 μm in length. The substrates expected of uses for evaluation of axon behaviors are available without fabricating guiding grooves by conventional soft lithographic methods requiring multiple stages and their treating times.

Novel dual Z-scheme Ag-bridged AgI/FeVO4-C3N4 plasmonic heterojunction: A study on the performance and mechanism of photocatalytic reduction of Cr(VI)

Proper design and synthesis of photocatalysts with efficient interfacial charge transfer, strong redox capabilities, and robust environmental applications are essential. Herein, a novel dual Z-scheme Ag-bridged AgI/FeVO4-C3N4 plasmonic heterojunction was successfully synthesized by a chemical deposition method. Compared with FeVO4, FeVO4-C3N4, AgI/C3N4, AgI/FeVO4, and AgI/FeVO4-C3N4, the optimized dual Z-scheme Ag@AgI/FeVO4-C3N4 composite exhibited an excellent photocatalytic reduction of Cr(VI) in water with approximately 100% reduction efficiency within 60 min. The reduction rate of Cr(VI) by Ag@AgI/FeVO4-C3N4 was estimated to be 0.0525 min−1, which was 3.5-fold and 26.2-fold of that by AgI/FeVO4-C3N4 and FeVO4, respectively. In addition, Ag@AgI/FeVO4-C3N4 showed good properties in terms of catalytic activity and 5 cycles stability. Furthermore, the reactive oxygen species •O2- and •OH enhancement processes were further verified by nitroblue tetrazolium (NBT) and terephthalic acid (TA) conversion experiments, respectively. Due to the strong force between AgI and FeVO4-C3N4 and the local surface plasmon resonance (LSPR) effect of Ag, a double Z-scheme heterojunction with rapid electron transfer ability was formed, which improved the photocatalytic performance of Ag@AgI/FeVO4-C3N4. Therefore, the new dual Z-scheme heterojunction Ag@AgI/FeVO4-C3N4 composites have a good application prospect in water purification. This study provides a new idea for the design of high-efficiency double Z-scheme photocatalysts and their application in the field of environmental purification.

Rechargeable non-aqueous lithium-O2 batteries: Novel bimetallic (Ni-Cu) conductive coordination polymer cathodes

The development of highly efficient catalysts for the reactions of oxygen reduction (ORR) and oxygen evolution (OER) is crucial for lithium-O2 (Li-O2) batteries. Herein is synthesized a π-d conjugated bimetallic coordination polymer (NiCu-BTA) by the aid of the chemical deposition method and applied as cathode catalyst for Li-O2 batteries. Due to the difference in the electronic structures of Ni and Cu, the degree-disorder and porosity of NiCu-BTA increased compared with the pure Ni-BTA and Cu-BTA, resulting in an enhanced electrocatalytic activity and battery performance. At a current density of 100 mA g−1, the Li-air battery equipped with NiCu-BTA shows a discharge specific capacity of 23,000 mAh g−1 and can be consistently cycled up to 113 times. The tunable catalytic activity in M-BTA opens a new window for the design of low-cost and multifunctional catalysts, and may find potential applications in clean and renewable energy fields.

Degradation bensulfuron-methyl by magnetic CoFe alloy@N-doped graphitized carbon derived from CoFe2O4 activated by peroxymonosulfate

Magnetic CoFe alloy@N-doped graphitized carbon nano-catalyst (CoFe@N-GC) was synthesized by hydrothermal method and chemical deposition method, which could couple with peroxymonosulfate (PMS) to degrade herbicide bensulfuron-methyl (BSM). CoFe alloy nanoparticles were encapsulated in N-doped graphitized carbon yarn-like material, providing strong stability and high corrosion resistance properties of them. Furthermore, CoFe alloy can make great improvement of degradation performance via tuning metal site’s intrinsic performance of the Fermi energy level density of states. CoFe@N-GC (k = 0.4 min−1) displayed better catalytic performance than CoFe2O4 (k = 0.14 min−1) because of the intrinsic strengths of each component, synergy between cobalt and iron, doping of nitrogen atoms and graphitized carbon and unique electronic properties. 10 mg·L−1 bensulfuron-methyl was degraded completely by the combination of CoFe@N-GC and PMS within 10 min at pH 7. Magnetic CoFe@N-GC could be separated from solution by an external magnet, thus making convenience to collect catalyst and avoiding second pollution. After 15 recycling use of CoFe@N-GC, the BSM degradation efficiency could still be maintained at 95%. CoFe@N-GC/PMS system exhibited stable degradation ability over a wide pH range (3–8) and displayed strong tolerance to real water samples. The main active species, possible BSM degradation pathways and potential reaction mechanism of CoFe@N-GC/PMS were systematically explored. Thus, our finding can provide an environmental friendly, efficient and easy recycle catalyst to degrade refractory organic matters by PMS activation.