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Effects of different complexing agents on the physical properties of ZnO nanoparticles
摘要： ZnO nanoparticles have been synthesised via a co-precipitation method using different complexing agents. X-ray diffraction (XRD) analysis revealed that ZnO nanoparticles were composed of a single hexagonal wurtzite phase. Transmission electron microscopy (TEM) analysis indicates that the samples prepared without any complexing agent have slight agglomeration characteristics presenting a prismatic morphology and a wider size distribution from 22 to 72 nm, which provides good material packing density. However, samples synthesised using urea and glycine are similar and show spherical-like morphology. XRD and TEM analyses indicate that complexing agents also have an important role in the size of the ZnO nanoparticles, where the average particle size of 47 and 22 nm were obtained using urea and glycine, respectively.
关键词： size distribution,glycine,ZnO,complexing agents,co-precipitation,urea,morphology,nanoparticles
更新于2025-09-23 15:19:57
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Synthesis, characterization, and application of fluorescent electrically conducting copolymer/metal-oxide nanocomposites
摘要： Solution polymerization of aniline in the presence of fluorescent organic dyes was carried out at 0–5°C for 2 h under nitrogen atmosphere with FeCl3 as an initiator. The copolymers were prepared under different experimental conditions. The prepared copolymers were characterized by various analytical tools. The electrical conductivity was measured. From the absorbance and emission intensity values the order of reaction was calculated. Further, its application toward the reduction of nitrophenol was done and the apparent rate constant (Kapp) was calculated. The Fourier Transform Infra Red (FTIR) spectrum confirmed the presence of benzenoid, quinonoid, and azo functionalities.
关键词： characterization,morphology,Copolymers,synthesis,conductivity,reduction
更新于2025-09-19 17:15:36
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Exudates Detection Using Morphology Mean Shift Algorithm in Retinal Images
摘要： Exudates is a serious complication causing blindness in diabetic retinopathy (DR) patients. The main objective of this study is to develop a novel method to detect exudates lesions in color retinal images by using a morphology mean shift algorithm (MMSA). The proposed methods start with a normalization of the retinal image, contrast enhancement, noise removal, and the localization of the OD. Then, a coarse segmentation method by using mean shift provides a set of exudates and non-exudates candidates. Finally, a classification using the mathematical morphology algorithm (MMA) procedure is applied, in order to keep only exudates pixels. The optimal value parameters of the MMA will facilitate an increase of the accuracy results from solely MSA method by 13.10%. Based on a comparison between the results and ground truth images, the proposed method obtained an average sensitivity, specificity, and accuracy for of detecting exudates as 98.40%, 98.13%, and 98.35%, respectively.
关键词： retinal image,mathematical morphology,mean shift algorithm,Diabetic retinopathy,exudates
更新于2025-09-19 17:15:36
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Characterization and NO2 gas sensing performance of CdO:In2O3 polycrystalline thin films prepared by spray pyrolysis technique
摘要： Polycrystalline CdO:In2O3 thin films for gas sensor applications were prepared on glass and silicon substrates by using one-step spray pyrolysis technique from the aqueous solution of CdCl2 and InCl3 at a substrate temperature of 300 °C. The structure, surface morphology, and the optoelectronic properties of prepared films were characterized respectively by means of X-ray diffraction (XRD), atomic force microscope and UV–visible spectroscopy. Based on the XRD results, the polycrystalline nature of CdO films has been confirmed, and In2O3 films were found to exhibit a preferred orientation along (222) diffracted plane. The grain size varies between 9.0 and 28.4 nm. The results of Hall effect measurement of CdO:In2O3 thin films confirms that all films were an n-type semiconductor. The electrical properties of prepared thin films and their sensitivity to nitrogen dioxide (NO2) gas are also studied. The influence of the operating temperature and In2O3 concentration on the NO2 response were investigated. It is found that all films are sensitive to NO2 gas, and the ideal operating temperature for the film contented 20 vol% of In2O3 was found to be 200 °C at a gas concentration of 25 ppm. The sensing mechanism of the CdO:In2O3 thin film is discussed and attributed to electron transfer between the sensing element and NO2 molecules.
关键词： NO2 gas sensor,Sensitivity,Optoelectronic properties,Structural,Morphology,Metal-oxide semiconductors
更新于2025-09-19 17:15:36
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Hierarchical biomimetic BiVO4 for the treatment of pharmaceutical wastewater in visible-light photocatalytic ozonation
摘要： Photocatalytic ozonation is an attractive advanced oxidation process for wastewater treatment, but highly active catalysts with strong response to visible light are urgently needed to push forward its practical application. In this study, a hierarchical biomimetic monoclinic bismuth vanadate (BiVO4) with leaves morphology was synthesized by a hydrothermal method, and employed as catalyst for oxalic acid and penicillin degradation in photocatalytic ozonation. The results show that the organics degradation was more efficient using leaves shaped BiVO4 as catalyst than the bulk shaped one in photocatalytic ozonation and the synergy index is ranged from 2.8 to 3.3, indicating a superior positive synergistic effect between photocatalysis and ozonation. The higher activity of the leaves shaped BiVO4 was probably attributed to the distinctive biomimetic morphology and preferable band structure with more negative CB potential. Mechanism studies suggested that the main reactive species were h+ and ?OH for the degradation of persistent oxalic acid in photocatalytic ozonation. In addition, the effect of ozone concentration and inorganic ions and reusability of the material were also intensively investigated.
关键词： BiVO4,biomimetic morphology,photocatalytic ozonation,synergies,photogenerated hole
更新于2025-09-19 17:15:36
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Appraisal of Bleb Using Trio of Intraocular Pressure, Morphology on Slit Lamp, and Gonioscopy
摘要： PurPOsE: The aim of this study was to assess bleb function using Wuerzburg bleb classification score (WBCS) for bleb morphology on slit lamp, intraocular pressure (IOP), and gonioscopy. MEthOds: A total of randomly selected 30 eyes posttrabeculectomy were assessed for bleb function with the trio of bleb morphology, IOP, and gonioscopy. Bleb was assessed using the WBCS of 0–12 on slit lamp, IOP was assessed using applanation tonometry, and visualization of inner ostium and iridectomy were assessed using gonioscopy. Postoperative patients of less than six weeks were excluded from the study. rEsults: The correlation between WBCS and the duration of trabeculectomy was found to be highly significant (P value = 0.029). The correlation of IOP with WBCS was also found to be strongly positive (P = 0.000). IOP was found to be highly associated with peripheral iridectomy (P = 0.000), internal window (P = 0.001), and bleb characteristics.
关键词： gonioscopy,bleb morphology,trabeculectomy,intraocular pressure,WBCS
更新于2025-09-19 17:15:36
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A Supramolecular Gel of Oxalic Acid-Monoethanolamine for Potential Schottky Barrier Diode Application
摘要： A functional supramolecular gel of oxalic acid and monoethanolamine (OXMEA) has been achieved through direct instant mixing of N,N-dimethyl formamide (DMF) solution of oxalic acid and pure monoethanolamine at room temperature under ambient condition. The rheological analysis established the viscoelastic semi-solid type nature of mechanically stable OXMEA supramolecular gel. The morphological pattern, imaged through field emission scanning electron microscopic investigation, explores the bean-seed like hierarchical architecture of the gel network. The semiconducting property of the gel was verified from band gap energy and conductivity estimation. The electrical charge transport property was also analyzed in the form of OXMEA gel based metal-semiconductor junction thin film device. The obtained nonlinear current-voltage characteristics of the device signify Schottky barrier diode nature of the synthesized gel. Overall, this work has been proof of development of semiconducting electronic device by OXMEA gel based gel medium.
关键词： Semiconductor,Morphology,Supramolecular Gel,Rheology,Schottky barrier diode
更新于2025-09-19 17:15:36
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Innovative visualization of crystal morphology effects on semiconductor photocatalysts. Tuning the Hückel polarity of the shape-tailoring agents: the case of Bi2WO6
摘要： The shape tailoring synthesis of different materials is a hot topic nowadays. The essence of morphology controlling processes is to tune the geometry of the crystal in such a way that a desired property of the crystal to be preponderantly enhanced. However, the main issue of such synthesis approaches is to get simple morphological correlations with the applied shape-tailoring agents. This specific situation is also valid for shape controlled photocatalytic materials. That is why in the present work Bi2WO6 microcrystals were obtained using two shape tailoring agents: Triton-X and amino acids/(tio)carbamide structures. The first one was applied as a binary variable (presence or absence), while in the case of the second one the Hückel polarity of the chalcogen-carbon double bond (C=O or S) was considered as the changing parameter. The as-prepared materials were characterized by XRD, DRS, SEM and IR spectroscopy and their activity was verified under visible light illumination using Rhodamine B as the model pollutant to enhance the general validity of the results. It was found that an empiric geometric function, defined as the “rose similarity decay constant”-RSDC, showed that a perfect rose shape (low RSDC) or geometries with similarly low RSDC exhibited high photocatalytic activity. Moreover, the introduced empiric value was correlated with the Hückel polarity of the samples, showing for the first time a direct association between a structural parameter of the shape tailoring agent, obtained crystal geometry and photoactivity.
关键词： rose similarity decay constant,morphology control,Hückel polarity,photocatalysis,bismuth tungstate,shape-tailoring
更新于2025-09-19 17:15:36
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Influence of trimethylaluminum predoses on the growth morphology, film-substrate interface, and microstructure of MOCVD-grown AlN on (111)Si
摘要： Aluminum nitride (AlN) was deposited on (111) silicon by metalorganic chemical vapor deposition after varied trimethylaluminum predoses. Growth morphologies, film-substrate interfaces, and film microstructures were examined using scanning electron microscopy, atomic force microscopy, X-ray diffraction, and transmission electron microscopy. In samples grown with predoses, lateral growth was observed over faceted "patches" formed during the predose. Three-dimensional growth was observed to seed from small islands on the surface of these patches and eventually overgrow them. The three-dimensional growth mode was similar to that observed when AlN was grown without a predose, resulting in similar morphologies in all films, regardless of predose, after the islands coalesced. The AlN-silicon interface was found to be predominantly amorphous when no predose was used. However, narrow regions were observed over which the film was in atomic registry with the substrate. This indicates AlN nucleates in epitaxy with the substrate and amorphous silicon nitride forms between nucleation sites due to ammonia exposure. Films grown with predoses had structurally abrupt interfaces, suggesting aluminum within the observed patch features inhibits the reaction between ammonia and silicon at the onset of growth. A structure distinct from both wurtzite AlN and diamond cubic silicon was observed at the substrate interface in films grown with a predose, consistent with either zinc blende AlN or a strained Si/Al alloy. A mosaic microstructure was observed in all films, grown with or without predoses, which consisted of sub-boundaries formed by clusters of threading dislocations. Threading dislocations, separated by hundreds of nanometers, were found to be tilted along common directions, providing evidence for a dislocation bending mechanism possibly enhanced by the predose.
关键词： Defects,Crystal morphology,Metalorganic chemical vapor deposition,Semiconducting aluminum compounds,Nucleation,Nitrides
更新于2025-09-19 17:15:36
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Electrodeposition of Single Phase SnS Thin Films: Effect of Electrolytic Bath Temperature on the Final Film Properties
摘要： In this article, the electrodeposition of single-phase tin monosulfide (SnS) films at different electrolytic bath temperatures is studied. The electrodeposition was carried out potentiostaticaly onto transparent conductive substrates (fluorine-doped tin oxide, and indium tin oxide on a glass substrate) from an acidic solution of SnSO4 and Na2S2O3 as tin and sulfur precursors, respectively. The films were characterized through different techniques: field-emission scanning electron microscopy, energy dispersive X-ray analyses, X-ray diffraction measurements, profilometry, Raman spectra, UV-vis measurements, electrochemical impedance spectroscopy and linear sweep photovoltammetry. The films obtained were stoichiometric and no other phases different from SnS were evidenced. A change in the morphology from cubic-like to sheet-like was observed with an increase of bath temperature, which was reflected in the texture coefficient obtained from X-ray diffraction analyses. The bandgap of the films was obtained using a direct absorption edge in the Tauc plots. A decreasing bandgap with electrodeposition temperature was observed, which is attributed to an improvement in the crystallinity of the films. Mott-Schottky plots and linear sweep photovoltammetry measurements confirmed that the films are p-type semiconductors. An increase in the photocurrent of the photoelectrodes was observed with the electrolytic bath temperature, which is attributed to the change of SnS morphology with the electrodeposition temperature.
关键词： bath temperature,morphology,Electrodeposition,photoelectrochemical properties,bandgap,SnS thin films
更新于2025-09-19 17:15:36