Concentration Of Spray Solution Research Articles

A novel method for fabricating semiconducting monocrystalline copper nitride nanowires for optoelectronic applications

Semiconducting grade copper nitride(Cu3N) nanowires have been fabricated using a simple and low-cost method. The standard technique for fabricating Cu3N nanowires is physical methods and this is costly due to the involvement of capital equipment and recurring input. In the present method the Cu3N nanowires have been fabricated using chemical spray pyrolysis of thiourea and ammonium hydroxide over hot copper (Cu) foil substrate surface. The present process involves meager capital equipment and low recurring input. Studies on the quality of nanowires fabricated by the present method have been conducted using various molar concentration of spray solution and the ambient temperature of Cu substrates. The structural analysis indicated about the formation of cubic Cu3N. The optical analysis indicated about the low absorption in UV range and enhanced absorption in visible and NIR ranges with variation of direct and indirect bandgap of nanowire ranging from 1.5 to 1.79 eV. The light dependent resistance of the fabricated nanowires was tested and indicated its applicability in usage as light sensing devices. The result obtained so far is similar with that of Cu3N nanowires fabricated by physical deposition method. The present method for fabrication of Cu3N nanowires is simple and can be adopted by industries for large scale fabrication of nanowires for various device applications. Detailed fabrication technique and various properties of the nanowires are discussed in the text of the paper.

Fabrication of epoxy/SiO2/ZnO superhydrophobic nanocomposite mesh membranes for oil-water separation: Correlating oil flux to fabrication parameters via Box-Behnken design

Superhydrophobic nanocomposite mesh membranes were constructed by facile scalable spray deposition method without using low surface energy modifiers for oil-water separation. The Box-Behnken design was applied to study the influence of the main fabrication parameters consisting of spray solution concentration (g.L−1), the mass ratio of SiO2:ZnO (wt%), and the mass ratio of epoxy resin to the total nanoparticles (wt%) on the permeation flux of mesh membranes. The results indicated that increasing the concentration of spray solution led to a decrease in the oil flux due to increasing the coating thickness. The permeation flux first decreased with an increase in the weight percentage of epoxy resin in the spray solution because of the formation of the high density of SiO2/ ZnO coating and then slowly increased due to decreasing coating thickness. The best performance of chloroform flux of 18.3E+03 L/m2.h and separation efficiency of >97% corresponded to the fabricated mesh membrane with 80 wt% of SiO2 to ZnO, 33.33 wt% of epoxy resin to total nanoparticles, and 30 g.L−1 of spray solution concentration. This mesh membrane exhibited superior superhydrophobic properties, outstanding chemical resistance, and excellent mechanical durability. The coated mesh displayed good icephobic characteristics with low ice adhesion.

Optical constants, optical dispersion and group index parameters of Mn2O3 thin films

In this work, we report on the diverse optical parameters of Mn2O3 thin films prepared by nebulized spray pyrolysis technique by the effect of spray solution concentration. X-ray diffraction study confirmed the Mn2O3 films belong to cubic structure. The Raman vibrational band observed at 636 cm−1 is related with the symmetric stretching of Mn–O bond of trivalent manganese ions (Mn3+). The surface morphological study showed that the nano-sized particles are homogenously distributed on the film surface. The films exhibit the highest transmittance in the near infrared region. The spray solution concentration induced reduction of Urbach energy (from 677 to 655 meV) indicates the decrease in degree of crystal defects in the film. The extinction coefficient of the film was obtained in the order of 10−2. It was observed that the optical dispersion threshold point (TODT) of Mn2O3 thin film is coincides with the refractive index threshold wavelength (λrtw) of the material. This was further corroborated from the intersection of phase velocity and group velocity curves at the point of λrtw or TODT. This indicates that no optical dispersion was taken place at that point and therefore the phase velocity is equal to the group velocity. The possible correlations among the data were made with the light of underlying concepts.

Fabrication of Oriented FTO Film Grown By Spray Pyrolysis

SnO2 behaves like an n-type semiconductor with a wide energy gap (~ 3.8 eV) and has a tetragonal structure which is similar to the rutile structure. Of the various potential dopants for SnO2, fluorine is preferred because F-doped SnO2 (FTO) films show high transparency and good conductivity. The spray pyrolysis method is the most convenient method because of its simple and inexpensive experimental arrangement and the ease with which doping materials can be added. However, there are few reports on the growth and detailed analysis of FTO films deposited by spray pyrolysis.In previous work1, transparent conducting oxide films of non-doped SnO2 and FTO were deposited on glass substrates at 500 °C by spray pyrolysis in order to determine the effect of spray solution concentration and substrate temperature. The films were all polycrystalline with tetragonal crystal structures. The best electro-optic properties were achieved with a fluorine doping concentration of 17 mol%. These conditions resulted in a film with an average optical transmittance of 82%, a resistivity of 4.0 × 10-4 Ωcm, a carrier concentration of 4.7 × 1020 cm-3 and a mobility of 34 cm2 (V s)-1.In this work, oriented SnO2 and FTO films were deposited on glass substrates by spray pyrolysis. The (110) or (200) orientation film could be obtained by means of the Sn solution concentration. Furthermore, low surface roughness could be also obtained by means of the sample thickness. Oriented FTO film with low surface roughness could be obtained by controlling two methods such as the Sn solution concentration and thickness. 1 M. Oshima, M and K. Yoshino, J. Electron. Mater. 2010, 39, 819-822.

Synthesis and characterization of hexagonal and tetrahedral nanocrystalline Sb2O3 thin films prepared by chemical spray pyrolysis technique

Abstract Nanocrystalline hexagonal and tetrahedral shape Sb2O3 thin films of different concentrations have been successfully deposited onto glass substrates using chemical spray pyrolysis technique for the first time. The structural, morphological and compositional studies were carried out using X-ray diffractometer (XRD), field emission scanning electron microscope (FESEM) and energy dispersive X-ray analysis (EDAX) respectively. The structural studies revealed that, deposited Sb2O3 thin films have polycrystalline nature having cubic senarmontite structure. The morphological and compositional studies revealed that deposited materials have hexagonal and tetrahedral shape which showing excellent agreement with theoretical composition. The optical characterization shows that deposited Sb2O3 exhibited direct band gap which varied from 3.43 to 3.71 eV depending upon the concentration of spray solution. Electrical resistivity of the Sb2O3 thin film decreases with an increase in temperature indicating the semiconducting nature. The activation energy of the film is found to be varying from 0.764 to 0.798 eV depending upon the concentration of spray solution.

Optical and Structural Properties of SnO<sub>2</sub> Thin Films Deposited by Spray Pyrolysis Technique: Effect of Solution Concentration

This article presents the elaboration of tin oxide (SnO2) thin films on glass substrates by spray pyrolysis technique. Our interest is on the investigation of Effect solution concentration on the structural, optical and morphological properties of the films. Structural analysis by X-ray diffraction showed that the deposited films are polycrystalline in nature with a tetragonal structure having a preferential orientation along with (1 1 0) plane. SEM micrograph proved the existence of small cracks on the film surface, EDS confirmed the composition percentage ratio of Sn and O2 and no trace of impurities could be detected. The spectrophotometer UV-Visible confirms that it is possible to get good transparent SnO2 films with a transmission of 80 to 90% in the visible. The values of optical band gaps vary between 3.6 and 4.0 eV depending on the spraying solution concentration.

Response of different pomegranate cultivars to foliar application of potassium nitrate in arid irrigated region of Punjab

Ambe-bahar crop response of four pomegranate cultivars to foliar applications of potassium nitrate (0, 0.5, 1.0, and 1.5%) in May–June was evaluated at Punjab Agricultural University Regional Research Station, Abohar, Punjab, India, during 2015 and 2016. The experiment was laid out in randomized block design, replicated thrice. Over control, potassium nitrate significantly improved growth and productivity of pomegranate. Different spray concentrations considerably influenced plant volume in Phule Arakta and Ganesh. The differences in fruit yield were non-significant in Bhagwa and Phule Arakta. In Mridula and Ganesh, maximum yield was noted at 1.5% sprays which, however, were statistically comparable to 1% sprays. Fruit quality also varied markedly with the type of cultivar and concentration of spray solution. From the study, it comes out that potassium nitrate sprays at 0.5% in Bhagwa and Phule Arakta is highly beneficial in maintaining higher productivity and quality of fruits. In Mridula and Ganesh, 1% sprays prove more advantageous.

The influence of concentration on the morphology of TiO2 thin films prepared by spray pyrolysis for electrochemical study

In the nanoscale architecture, expected morphology plays an important role in the fabrication of supercapacitive devices due to their highly porous properties. Herein, a well-defined rutile TiO2 architecture was successfully prepared by spray pyrolysis technique (SPT), by changing the concentration of the spraying solution from 0.01 to 0.1 M at 723 K deposition temperature onto stainless steel substrates. The thermal decomposition behavior of the precursor is analyzed using thermogravimetric analyzer. As-deposited thin film electrodes exhibits rutile tetragonal crystalline structure confirmed using XRD. FT-IR study indicate the presence of Ti=O stretching vibration in the range 400–1000 cm−1. The obtained nanostructures merely changes by changing the concentration of spraying solution and process parameters as strongly evidenced using SEM. TEM image and SAED pattern confirms the formation of nanorods and rutile tetragonal structure of TiO2. EDAX confirms formation of pristine TiO2. Wettability of samples shows angle of contact changes by changing the sample thickness and surface roughness of the samples. Optimized electrode shows maximum specific capacitance 273.84 F/g at 2 mV/s in 1 M KOH. Maximum values of specific energy (SE), specific power (SP) and efficiency as observed using galvanostatic charge–discharge are 04.32 Wh/Kg, 70.27 KW/Kg and 90.37%, respectively.

NO2 sensing properties of porous fibrous reticulated WO3 thin films

In this work, the WO3 thin films were synthesized onto glass substrates at 673K by simple and cost-effective spray pyrolysis technique for the NO2 gas sensing. Moreover, the WO3 thin film was synthesized as a function of different spray solution concentration. The structural and morphological results reveal the polycrystalline nature of WO3 thin films with pure monoclinic phase having porous fibrous reticulate morphology. The optical band gaps of WO3 thin films were observed ∼2.73eV. Moreover, the activation energy in our WO3 sample (0.368eV) is maximum than the theoretical value of activation energy (0.031eV). Due to the outstanding morphology and grater activation energy, the WO3 thin films were used for NO2 gas sensing. The gas sensing properties of the thin film sensor based on WO3 thin films were studied in the range of 1–100ppm of the NO2 at an operating temperature of 423K (or 150°C). The sensor exhibits better gas response around 5.75 for 5ppm of NO2 gas as well as 84.75 for 100ppm NO2 gas with better selectivity.

Spray pyrolyzed indium oxide thick films as NO2 gas sensor

Metal oxides are proven as efficient materials in the detection of various toxic gases at moderately high temperature. In this study, efforts are made to deposit indium oxide (In2O3) thick films by using a simple spray pyrolysis method. The In2O3 films were deposited at different concentrations of spray solution at 400°C. The solution concentration was varied over 0.03–0.1M. The structural and morphological properties of In2O3 films were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The cubic crystal structure of synthesized In2O3 films was confirmed by XRD patterns. The crystallite size increases with the increase in the solution concentration. The surface morphology was substantially changed with solution concentration and revealed increase in average grain size. The nanopetal like morphology was obtained at 0.07M spray solution concentration. The deposited In2O3 films were employed for gas sensing applications. The In2O3 films deposited at 0.07M solution concentration showed maximum sensor response (Rg/Ra)~33.45 at 150°C for 100ppm of NO2 gas.

Effect of solution concentration on the structural, optical and electrical properties of SnO2 thin films prepared by spray pyrolysis

The aim of this work is the production of tin oxide thin films with a suitable optoelectronic properties required for application as transparent electrodes. Using a simple and inexpensive homemade spray pyrolysis system of tin chloride (SnCl2) onto glass substrates. The motivation for the use of this technique is its simplicity and effectiveness of preparation. The effect of the molarity (0.05–0.25 mol/l) on structural, optical and electrical film properties was investigated. The results obtained with several characterization techniques such as DRX, AFM, UV–visible transmission and four probe points measurements are well consistent and suggest that the prepared films were uniform and well adherent to the substrates. All the films are polycrystalline in nature with a tetragonal structure having a preferential orientation along the (1 1 0) plane. The obtained SnO2 films, not only have an average transmittance greater than 80% in the visible region, but also have an optical band gap between 3.84 and 4.14 eV depending on the spraying solution concentration. Moreover, the measured electrical conductivity at room temperature was found in the order of 102 (Ω cm)−1.

Study of Zn(O,S) films grown by aerosol assisted chemical vapour deposition and their application as buffer layers in Cu(In,Ga)(S,Se)2 solar cells

Manufacturing chalcopyrite thin film solar cells from cost-efficient and environmentally friendly materials is of high priority. Therefore, the materials used in buffer layer production nowadays (such as indium and cadmium) need to be substituted. Zn(O,S) is considered to be a potential buffer layer material when deposited with a fast and inexpensive method. Zn(O,S) layers have been prepared by aerosol assisted chemical vapour deposition (AACVD) technique. AACVD technique is a simple non-vacuum process where the thin film deposition temperatures do not exceed 250°C. 10mM spray solution was made by dissolving zinc(II)acetylacetonate monohydrate in ethanol. The films were grown on Mo substrate at 225°C (film growth temperature). The effect of deposition parameters (spray solution concentration, N2 flow rate, H2S flow rate) on Zn(O,S) thin film properties were studied with SEM and XRD. Thereupon optimising the deposition parameters, homogeneous and compact Zn(O,S) thin films were obtained and the films were employed in the chalcopyrite thin film solar cell structure by growing films on Cu(In,Ga)(S,Se)2 substrates industrially produced by BOSCH Solar CISTech GmbH. The resulting cells were studied using current–voltage and quantum efficiency analysis and compared with solar cell references that include In2S3 and CdS as buffer layer deposited by ion layer gas reaction and chemical bath deposition, respectively. The best output of the solar cell containing Zn(O,S) as buffer layer and without intrinsic ZnO under standard test conditions (AM 1.5G, 100mW/cm2, 25°C) is: Voc=573mV, Jsc=39.2mA/cm2, FF=68.4% and efficiency of 15.4% being slightly better than the In2S3 or CdS containing solar cell references.

Effect of foliar fertilization of Capsicum annuum L. together with optimal root fertilization in hydroponic culture on fruit yield and its capsaicin content

The Wrocław version of hydroponic culture was applied. The optimal dose of mineral nutrient solution for root-fertilizing was found to be 19,6g and 22,4g of mineral salts per one plant during the whole vegetation season. In a separate experiment plants with optimal root fertilization were sprayed with multicomponent solutions of mineral salts. The sprays were applied weekly for 15 weeks. The concentrations of solutions for spraying were: 0,28, 0,84 and 1,4 per cent. The greatest increase of fruit yield was noted after the 0,84 per cent solution. At optimal concentration of spray solution (0,84%) chelating agents added (EDTA or humate) had no effect. Addition of the chelating agents to the 1,4% solution attennated its inhibitory effect. The humate gave a better effect than EDTA. A tenfold increase of microelements content (6 mg/l of each instead of 0,6 mg/l) in 0,28 per cent spray solution produced a marked increase of the yield of fruits and of their capsaicin content.

Controle de Brachiaria decumbens Stapf com adição de ureia à calda do glifosato

A adição de fontes nitrogenadas a caldas de herbicidas tem sido relacionada a melhorias em tratamentos fitossanitários. Objetivou-se, neste trabalho, avaliar a eficácia no controle de Brachiaria decumbens, com a adição de ureia à calda do glifosato. Os tratamentos constituíram-se pela combinação de doses de glifosato (0,0 g ha-1, 360,0 g ha-1, 720,0 g ha-1 e 1.080,0 g ha-1 do i.a.) e de ureia (0,0 g L-1, 7,5 g L-1, 15,0 g L-1 e 25,0 g L-1 de calda) e uma testemunha sem aplicação, em delineamento em blocos casualizados, em esquema fatorial 4x4, com três repetições. As aplicações foram realizadas com pulverizador de pressão constante de CO2, equipado com barra para duas pontas de jato plano, operando à pressão de 300,0 kPa. Foram avaliadas as densidades e percentagem de cobertura das folhas das plantas, proporcionadas pelas gotas produzidas pelas pontas hidráulicas, bem como as trocas gasosas instantâneas às 12 horas, aos 2, 4, 6 e 11 dias após a aplicação (DAA), utilizando-se um analisador infravermelho portátil de gás. Realizaram-se avaliações visuais da percentagem de controle aos 7, 14, 21 e 28 DAA. Não foi observada diferença na densidade e cobertura das folhas, nas diferentes concentrações de ureia. A adição de ureia à calda do glifosato promoveu incrementos no controle de B. decumbens, independentemente da dose do herbicida, com o uso de concentrações de até 25,0 g L-1 de calda. A troca gasosa de B. decumbens foi menor a partir dos 6 DAA, nos tratamentos com maiores concentrações de ureia na calda do herbicida, resultando em maior controle, nestes tratamentos.

Diagnóstico e proposta de descrição metodológica para artigos técnico-científicos que tratam da avaliação de aplicações de herbicidas

Chemical control is a viable tool and practically essential in the management of weeds control. However, insufficient details about application methods of pesticides have been observed in most scientific publications that deal with herbicides utilization. With the objective of verifying the presence or absence of basic information about herbicides application found in scientific papers, as well as to propose a criterion of minimum description needed with information that may guarantee better repeatability of methods and techniques used, it was conducted a survey in 200 papers published in national and international periodic. It was observed that minimum descriptions required about herbicides application technology have not been observed. Besides all papers showed the used application rate (L ha -1 ), outstanding with insufficiency the description of droplets spectrum formed by sprayer, with lack of information in 84.5% of evaluated works; work pressure (15.5%); spray solution concentration (20.5%); distance and position of nozzles in relation to the target (58.5%) and meteorological conditions, with median absence (temperature, air humidity and winds speed) of 62.6% in evaluated papers. In order to rescue the importance of criterion description about herbicides application technologies in scientific papers, it was elaborated a simplified methodological description, that offers to maximize the security and fidelity in information’s reproduced referred to weeds control.

Characteristic of Low Resistivity Fluorine-Doped SnO2 Thin Films Grown by Spray Pyrolysis

Transparent conducting oxide films of fluorine-doped SnO2 (FTO) were deposited on glass substrates by spray pyrolysis in order to determine the effect of spray solution concentration. These films were prepared with different F-doping concentrations from 0 to 33 mol %. The films were all polycrystalline with tetragonal crystal structures. The best electro-optic properties were achieved with a fluorine doping concentration of 17 mol % at a substrate temperature of 500 °C. These conditions resulted in a film with an average transmittance of 82%, a resistivity of 4.0 ×10-4 Ω cm, a carrier concentration of 4.7 ×1020 cm-3 and a mobility of 34 cm2 V-1 s-1.

Nanoscale Texture Control of Polyelectrolyte Multilayer Using Spray Layer-by-Layer Method

Weak polyelectrolyte multilayer thin films deposited by sequential spraying of poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) solutions are described. Using the spray layer-by-layer (spray-LBL) method, nanoscale texture structures were fabricated considering several factors such as the concentration of spray solution, spray quantity, and the flow rate of spray solution. It was also found that the formation of nanoscale texture structures was dependent on all three factors. Then, their surface morphologies were characterized. The surface morphologies of the fabricated films were observed by field-emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). The FE-SEM and AFM images showed that using the spray-LBL method, the surface morphology can be controlled with nanometer-order accuracy. As a result, the speed of fabricating thin films by the spray-LBL method was markedly increased compared with that by the dipping LBL method.

Nanoscale Texture Control of Polyelectrolyte Multilayer Using Spray Layer-by-Layer Method

Weak polyelectrolyte multilayer thin films deposited by sequential spraying of poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) solutions are described. Using the spray layer-by-layer (spray-LBL) method, nanoscale texture structures were fabricated considering several factors such as the concentration of spray solution, spray quantity, and the flow rate of spray solution. It was also found that the formation of nanoscale texture structures was dependent on all three factors. Then, their surface morphologies were characterized. The surface morphologies of the fabricated films were observed by field-emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). The FE-SEM and AFM images showed that using the spray-LBL method, the surface morphology can be controlled with nanometer-order accuracy. As a result, the speed of fabricating thin films by the spray-LBL method was markedly increased compared with that by the dipping LBL method.

Fabrication of Fine Particles of Semiconducting Polymers by Electrospray Deposition

Semiconducting polymers, poly(1,4-phenylene) (PPP) and poly(4-diphenylaminostyrene) (PDAS), which are soluble to organic solvents, were synthesized and were deposited by means of electrospray deposition (ESD). The ESD generated spherical shells of diameters ranging from a few to several tens of microns. The shells consisted of coagulation of nanometric particles of the semiconducting polymers. Formation of the shells was largely influenced by the concentration of spray solution. It was also found that the formation of shells can be achieved with various types of soluble polymers.

Intrinsically electroactive polyimide microspheres fabricated by electrospraying technology for ascorbic acid detection

In this paper, we present the first fabrication of intrinsically electroactive polyimide microspheres (EPS) based on conjugated segments of an electroactive amino-capped aniline trimer (ACAT) of a diamine, 4,4′-(4,4′-isopropylidenediphenoxy)-bis(phthalic anhydride) (BSAA) and a dianhydride. EPS was successfully prepared using electrospraying technology and applied in the detection of ascorbic acid (AA). The particle size of EPS can be controlled by varying the concentration of spraying solution, while the electrocatalysis oxidation properties can be influenced by the different particle sizes of EPS. A sensor constructed using an EPSS (EPS with a small particle size)-modified carbon paste electrode (CPE) was found to show 4.38-fold and 1.81-fold higher electrocatalytic activities towards the oxidation of AA than those constructed using an EPI (electroactive polyimide) thin film and EPSL (EPS with large particles size), respectively.