Crystalline Size Research Articles

Chemical and green synthesized Co/Ni-doped hematite nanoparticles for enhancing the photocatalytic and antioxidant properties

This research focuses on developing environmentally friendly and economically viable Co/Ni-doped hematite nanoparticles (HNPs) through both chemical and green synthesis methods and evaluated their potential for biomedical and environmental applications. The chemical synthesis employs polyvinylpyrrolidone (PVP), while the green approach utilizes Azadirachta indica (A. indica) leaf extract as a stabilizing agent. Co/Ni-doped HNPs are crystalline size ranging from 14 to 21 nm, morphology analysis revealed that the NPs exhibited a quasi-spherical, with an average particle size ranging from 15.98 to 25.91 nm, and dopants confirmed to contain by the XPS spectra. VSM study explains magnetic parameters, coactivity, residual magnetism, and magnetization. A. indica plants contain quinones, saponins, glycosides, alkaloids, and flavonoids. Characterization of the nanoparticles reveals optimized Co/Ni-doped HNPs with enhanced photocatalytic activity. These nanoparticles exhibit a remarkable 93%–95% degradation of UV-reactive dyes (methyl orange and methylene blue) within 90 min, attributed to structural and surface modifications that improve light absorption and enhance charge separation. The study concludes that green-synthesized Co/Ni-doped HNPs outperform chemically synthesized counterparts as superior photocatalysts. Additionally, antioxidant evaluations using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO) assays suggest significant antioxidant capabilities. A high scavenging activity percentage, ranging from 83% to 88%, was observed, which increased with higher concentrations of the synthesized Co/Ni-doped HNPs making these nanoparticles suitable for biomedical and environmental applications that require a magnetic system. In this study, the IC50 values for the antioxidant activity of chemically and green synthesized Co/Ni-doped hematite nanoparticles against the DPPH/NO assay were calculated to be 18.33 μg ml−1 and 16.09 μg ml−1, respectively. The research highlights the multifunctional properties of Co/Ni-doped HNPs, addressing the demand for tailored inorganic magnetic nanoparticles with minimal ecological impact.

Characterization of structural and spectroscopic properties of ZnO/Fe₂O₃ nanocomposites

Powder nanoparticles of ZnO/Fe2O3 composites with varying concentrations of precessour have been synthesized with the help of the co-precipitation method followed by annealing and milling the composite at 700 °C. Then, the obtained powder composites were characterized by X-ray diffraction, Fourier Transformation Infrared spectroscopy, Field Emission Scanning electron microscopy with EDX, Raman spectroscopy, UV–visible absorption spectroscopy, and Photolumnisences. The powder X-ray diffraction results show the formation of the well-crystalline phase of ZnO/Fe2O3. For the further study of the structural analysis, we have done the Rietveld refinement of the XRD data. Williams-hall plot was used to calculate the lattice strain of the composites. Crystalline size, dislocation density, and Rietveld parameters were also calculated using the XRD and Rietveld refinement methods. FESEM study revealed that with an increase in the concentration of Fe2O3, the shape of the composite changes from spherical to nanosheets via nanorods. The absorption peaks and vibration band obtained at zftir and RAMAN spectra show the formation of the ZnO/Fe2O3. The UV–visible absorption spectroscopy shows the maximum absorption peak in the 200–400 nm range. The successfully synthesized nanocomposites ZnO/Fe2O3 indicate that it can be a potential candidate for organic pollutant degradation.

Exploring electrochemical kinetic behaviors and interfacial charge transfer of pure and Ni-doped ZnFe2O4 nanoparticles-based sensing nanoplatform for ultra-sensitive detection of chloramphenicol

ZnFe2O4 (ZFO) nanomaterial was doped with a divalent transition metal cation of Ni2+ (NixZn1-xFe2O4, x=0, 0.2, 0.4, and 0.8) and characterized by various analytical techniques. Powder X-ray diffraction revealed the formation of a single-phase cubic spinel structure, while the stabilization of crystal structure for Ni2+-doped samples was observed. The average crystalline size, d-spacing, and lattice parameters increased with increasing in Ni2+ concentration within NixZn1-xFe2O4, due to differences in the ionic radius, the cation distribution at A-B sites, and the creation of surface oxygen vacancies within ZFO structure. From electrochemical measurements, NixZn1-xFe2O4-based electrodes showed excellent enhancements in charge transfer ability and conductivity with the highest rate constant (0.018 ms−1), the lowest peak-to-peak separation (206 mV), the lowest Rct (118 Ω), and the largest electrochemical active area (0.248 cm2), compared to that of bare SPE. Among them, Ni0.8Zn0.2Fe2O4/SPE provided outstanding electrochemical behaviors and achieved the best sensing performance with the widened concentration linear range from 0.25 to 50 μM and a rather low detection limit of 0.2 μM for chloramphenicol detection. The most important reason for this positive advance comes from the unique synergistic effects of Ni doping into the ZFO host structure. The excellent enhancements in adsorption capacity (Г) (1.4 times higher), number of oxygen vacancies, charge transfer rate constant (approximately 1.15 times higher), and catalytic rate constant (30 times greater) were recorded at Ni-doped ZFO-based electrodes, compared to pure ZFO-based electrode. Furthermore, the detailed hypotheses and possible mechanisms explaining these impressive enhancements were explored. Our work provides insight into the correlation between the Ni-doping and electrochemical characteristics, which has implications for tailoring the electrochemical performance of spinel ferrites across diverse applications and the design of novel spinel ferrite nanomaterials.

The role of phase transformation (tetragonal – spinel) on the structural and mechanical properties of Ni doped CuFe2O4

Nano-ferrites of Cu1–xNixFe2O4 (x = 0 to 1 with step 0.2) system was synthesized utilizing the flash auto combustion process annealed at 600oC for 3 h. The structural characterization for synthesized samples was carried out using x-ray Diffraction (XRD), Fourier transition infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The hardness of the prepared material was measured using micro-indentation creep technology. XRD pattern verified the creation of a single-phase cubic spinel structure. The undesired CuO phase forms around \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\:2\ heta\\:={50}^{^\\circ\\:}\\:$$\\end{document}for pure Copper ferrite and decreases with increasing Ni content. The average crystalline size decreases from 27.92 nm to 13.28 nm by doping process from x = 0.2 to x = 1 which retards the growth of crystalline size. FTIR spectra are distinguished by the presence of two prominent absorption bands, ν2 for the octahedral site and ν1 for the tetrahedral site, in the range of approximately 593 and 471 cm− 1, respectively. FTIR analysis verified the formation of the ferrite system’s spinel structure. The TEM images show a nanocrystalline nature with some agglomeration and the crystallites are spherical in shape which their sizes are agrees well with that obtained from XRD measurements. The hardness decreases as the dwell time increases. The hardness and yield strength (Y) values were significantly improved due to the decrease in the crystallite size after Ni doping. The stress exponent (n) value increases by increasing Ni content which means that the mechanical properties improved due to increment of resistance.

Modifications of some physical properties of nanostructured indium doped Co3O4 thin films

Using the chemical spray pyrolysis (CSP) technique, nanostructured undoped and Co3O4:In thin films are deposited. The effect of indium doping content in Cobalt ranged from 1% to 3% on optical, structural, and topographical properties of Co3O4 nanostructured thin films. No new peaks belonging to the In phase were seen, according to X-ray diffraction research, which revealed that pure and Co3O4: In thin films are polycrystalline in and cubic phase with (111), (311), (400), and (511) preferable orientation for all filmsThe Scherrer formula computation of average crystallite size shows that the size of Nano crystallites grows when doping is enhanced. AFM micrographs demonstrated how the surface shape of the films was discovered to be influenced by the inclusion of indium in the Co3O4 location.SEM images of Undoped Co3O4 and Co3O4:In films (CSP technique), showing separate semi-spherical blocks (120-200 nm) of nanoparticles (<30 nm). Band gap values for pure and doped were 2.52 to 2.38 eV. Resistance increases with increases Indium-doping, indicating more charge carriers and potential surface roughness influence. Sensitivity decreases with higher Indium concentrations, attributing to enhanced crystallinity and nano-crystalline size.

Graphene Oxide Decorated with Nickel Cobaltite Nanoparticles as an Adsorbent for Cationic Methyl Green Dye: Kinetic, Isotherm, and Thermodynamic Studies

‎تم في هذه الدراسة ، تزيين ‏رقائق أكسيد الجرافين (‏GO‏) بجسيمات ‏كوبلتيت النيكل النانوية ‏NiCo2O4‎‏(‏NC‏) عن طريق الترسيب في ‏الموقع ، وتم استخدام المتراكب ‏المحضر (‏NC: GO‏) كسطح ماز لإزالة ‏صبغة الميثيل الخضراء ( ‏MG‏) من ‏المحاليل المائية. تم التحقق من ‏التغطية الناجحة لأوكسيد الجرافين ‏بجزيئات كوبلتيت النيكل النانوية ‏‏(‏NC‏) باستخدام دراسات ‏FT-IR‏ وحيود ‏الأشعة السينية (‏XRD‏). كانت أحجام ‏الجسيمات البلورية لل ‏NC‏ و ‏ لل ‏GO‏ المزين ب NCهي ‏‎10.53‎‏ نانوميتر ‏‏9.30 نانومتر على التوالي. تم دراسة ‏تأثير العديد من العوامل التجريبية ‏، بما في ذلك زمن التلامس ، وكمية ‏السطح الماز ، ودرجة الحرارة. كان ‏وقت التلامس الأمثل وكمية السطح 120 ‏دقيقة و 3 مجم / لتر على التوالي. ‏تتلائم بيانات الامتزاز بشكل أفضل مع ‏ايزوثيرم ‏Freundlich‏. تم استخدام ‏أربعة نماذج حركية لتتبع عملية ‏الامتزاز: معادلة زائفة من الدرجة ‏الأولى ، ومعادلة زائفة من الدرجة ‏الثانية ، ومعادلة الانتشار داخل ‏الجسيمات ، ومعادلة بويد. أظهرت ‏نمذجة البيانات التجريبية أن حركية ‏الامتزاز كانت ممثلة بشكل جيد ‏بنموذج الرتبة الثانية الزائفة (‏R2 ‎‎= 0.9945‎‏) مع معدل ثابت سرعة يبلغ 3.2 ‏‏× 10 - 3 (جم / مجم. دقيقة). يتم ‏امتصاص صبغة ‏MG‏ تدريجيًا بواسطة ‏الجسيمات النانوية ‏NC‏ من خلال ‏الانتشار داخل الجسيمات ويتم ‏الاحتفاظ بها بعد ذلك في مسام أصغر. ‏أظهرت قيم التحليل الديناميكي ‏الحراري أن عملية امتزاز صبغة ‏MG‏ ‏كانت ماصة للحرارة بطبيعتها ، و ‏تلقائية وعملية الامتزاز فيزيائية. الكلمات المفتاحية: الانتشار داخل الجسيمات ، المسافات البينية، النموذج الزائف من الدرجة الأولى ، معادلة بويد

Modifications of some physical properties of nanostructured indium doped Co3O4 thin films

Using the chemical spray pyrolysis (CSP) technique, nanostructured undoped and Co3O4:In thin films are deposited. The effect of indium doping content in Cobalt ranged from 1% to 3% on optical, structural, and topographical properties of Co3O4 nanostructured thin films. No new peaks belonging to the In phase were seen, according to X-ray diffraction research, which revealed that pure and Co3O4: In thin films are polycrystalline in and cubic phase with (111), (311), (400), and (511) preferable orientation for all filmsThe Scherrer formula computation of average crystallite size shows that the size of Nano crystallites grows when doping is enhanced. AFM micrographs demonstrated how the surface shape of the films was discovered to be influenced by the inclusion of indium in the Co3O4 location.SEM images of Undoped Co3O4 and Co3O4:In films (CSP technique), showing separate semi-spherical blocks (120-200 nm) of nanoparticles (<30 nm). Band gap values for pure and doped were 2.52 to 2.38 eV. Resistance increases with increases Indium-doping, indicating more charge carriers and potential surface roughness influence. Sensitivity decreases with higher Indium concentrations, attributing to enhanced crystallinity and nano-crystalline size.

Bismuth doping for enhanced physical and electrochemical properties of CuO–ZnO thin films for complete degradation of Rifampicin and other antibiotics alongside organic dyes

In the current Study, undoped and bismuth doped CuO + ZnO coupled oxide thin films were meticulously deposited on glass substrates utilizing the spray pyrolysis technique. The effect of bismuth doping level in the structural, morphological, optical, electrical and electrochemical properties of these thin films were systematically investigated. X-ray diffraction patterns unequivocally confirmed the polycrystalline nature of the films, showcasing a combination of monoclinic CuO and hexagonal wurtzite ZnO phases. Furthermore, at a doping level of 8 %, the presence of the bismuth phase was observed, indicating its incorporation into the CuO–ZnO matrix. As the bismuth doping level increased, we observed a noticeable improvement in crystallinity and grain size. The distinctive characteristics of the developed thin films underscored a discernible enhancement in physical and electrochemical properties with the increase of bismuth doping level. Subsequently, The 8 % bismuth-doped CuO–ZnO thin films exhibit remarkable efficiency in degrading pharmaceutical compounds. Specifically, within a mere 2-h timeframe, these films demonstrate an exceptional degradation efficiency of 99 % towards Rifampicin, a widely used antibiotic. Moreover, their efficacy extends to other pharmaceutical pollutants, showcasing a significant degradation of 77 % for Ampicillin, an antibiotic commonly used to treat bacterial infections, and an even more substantial degradation of 90 % for Rhodamine B, a prominent dye compound. This underscores the promising potential of 8 % bismuth-doped CuO–ZnO thin films in addressing environmental and health-related challenges associated with pharmaceutical contaminants.

Exploring the molecular biology of zinc-doped hydroxyapatite nanocomposites as fillers for dental materials: a self-defensive approach targeting bacterial DNA

Abstract Infections during or after the denture filling pose a serious threat to recovery later, and antibiotics are scanty for quick healing. The antibacterial potential of Zn has convinced us to fabricate its composites with hydroxyapatite (HA), which has distinct biological properties. The main aim of the study is to evaluate the antibacterial potential of Zn-doped HA and investigate its molecular interaction with bacterial strains to enhance its defensive ability against bacterial attack. This study investigates the synthesis of zinc-doped hydroxyapatite nano-powder (Zn-HA) as coating and filling materials for dental applications. The co-precipitation technique was used in this regard to obtain the purest form of nanoparticles. The as-prepared Zn-HA samples were characterized by FTIR spectroscopy to assess the interaction of functional groups between components, X-ray diffraction (XRD) to determine percentage crystallinity, SEM to explore the surface morphology of composites, and EDX to confirm the incorporation of Zn in the apatite structure. The crystalline size of Zn-HA decreases from 99 nm to 40 nm with an increase in the doping of Zncl2 from 0 to 2.5g. With increasing the concentration of Zn doping, the effectiveness of antibacterial potential was increased. Due to an increased in the concentration of doped Zn, the Zn ions effectively rupture the bacterial membrane and destroy its DNA. Meanwhile, it shows the highest antibacterial activity against Pseudomonas (20.2±0.02), Klebsiella (25.8±0.05), Bacillus (18.3±0.09), S. aureus (24±0.03), and E. coli (19.3±0.09) with Zn/HA5.It showed that by increasing the concentration of Zinc ions in hydroxyapatite, the antibacterial potential increased. This increased concentration of zinc ions in HA enhances its-defensive ability against the attack of various bacterial strains, this makes it a potential material and enhances its efficacy in dental applications like coating, filling material, or dental restoratives, in inhibiting the growth of bacterial colonies and biofilm formation in the oral cavity. In this way, Zn/HA as an efficient dental composite as a restorative material with enhanced antibacterial potential may help to mitigate the risk of dental infections, promote dental as well as oral health, and overall improve the life of dentine.

Improvement the dielectric and impedance properties of Pb-free Bi0.5Na0.5TiO3-SrTiO3 piezoelectric materials modified by Fe2O3

The focus of this study is on the Fe2O3-doped Bi0.5Na0.5TiO3-SrTiO3 piezoelectric material. This is important to find ecologically acceptable piezoelectric materials. This research aims to obtain a lead-free piezoelectric material because lead is a material that is not environmentally friendly. An alternative solution is a piezoelectric material based on BNT-ST, which in this case is doped with Fe2O3 material. The study of Fe2O3 doped Bi0.5Na0.5TiO3-SrTiO3 piezoelectric material prepared by the solid-state reaction method was carried out to determine the optimum composition of the material formed. Doping variations are 0; 2.5; 5; 7.5; and 10 in mol %. The examinations were performed using X-ray diffraction (XRD) spectroscopy, a Scanning Electron Microscope (SEM), and an LCR meter. The Fe2O3 doped Bi0.5Na0.5TiO3-SrTiO3 produced a new compound in the form of FeBi5Ti3O15-Na2Ti3O7-SrTiO3 with the crystal structure of cubic, orthorhombic, and monoclinic, as well as the increasing crystalline size with the addition of dopants, exclude at 5 mol % and 7.5 mol %. FeBi5Ti3O15-Na2Ti3O7-SrTiO3 also produces varying particle sizes, which are between 0.88–8.23 µm. From the obtained data, the optimum composition of Fe2O3 doped Bi0.5Na0.5TiO3-SrTiO3 was the 2.5 mol % of Fe2O3 due to it having the highest dielectric constant (er ) and temperature Curie (Tc ), and also the lowest material impedance (Z) with the er of 12.037 at Tc of 400 °C and Z of 135 kΩ. The high piezoelectricity, which is indicated by the high value of the dielectric constant and Curie temperature, is possible due to the presence of a greater number of sodium ions in the Na2Ti3O7 phase. Sodium ions are ions with good electrical storage capabilities. The increase in dielectric constant in the BNT-ST piezoelectric obtained by the addition of Fe2O3 shows that this material can be used as a substitute for lead-based piezoelectric materials so that it is secure for the environment. The piezoelectric material of BNT-ST doped with Fe2O3 earned from this research can be applied to obtain electricity with a optimal value when given mechanical pressure

Crystallinity control on Bi2MoO6 microspheres for improved photocatalytic oxygen evolution

Crystallinity of the photocatalyst has a profound impact on its reactivity. Here, flower-like Bi2MoO6 microspheres were synthesized via a solvothermal method and subsequently calcined at varying temperatures to regulate the crystallinity and particle size. The thermally treated samples exhibited enhanced photocatalytic oxygen evolution compared to the pristine Bi2MoO6. Higher calcination temperatures led to the formation of larger crystallites, significantly boosting the activity. We demonstrate that crystallinity, rather than surface area, plays a more vital role in governing the photocatalytic performance of Bi2MoO6. Improved crystallinity can thicken the space charge layer (SCL), resulting in a greater band bending that facilitates the separation of electron-hole pairs. Conversely, poor crystallinity leads to an abundance of surface and bulk defects, promoting electron-hole recombination. Overall, efficient charge separation and suppressed recombination endow the calcined Bi2MoO6 with enhanced water oxidation efficiency.

Mechanochemical carbonation of recycled concrete fines: Towards a high-efficiency recycling and CO2 sequestration

The relative slow carbonation efficiency for conventional wet and dry carbonation of recycled concrete fines (RCF) limits its resource industrial utilization. In this study, an innovative mechanochemical carbonation (MC) method was developed. The carbonation kinetics, phase assemblage and microstructure evolution of RCF during the MC process were extensively examined. The results exhibited a substantial enhancement in the carbonation efficiency and CO2 utilization rate, as evidenced by achieving a notable carbonation degree within 10 min. This accomplishment surpassed what could be achieved even after a prolonged 2 h period of wet carbonation, and the CO2 uptake capacity and utilization rate achieved via MC reached >0.3 g-CO2/g-RCF and 80 %, respectively. The superior performance of MC was ascribed to the influence of mechanochemical effects. These effects contributed to the refinement in the geometrical characteristics of RCF, exfoliation of the passivating layers, and facilitation of CO2 dissolution, which favored the structural disintegration of RCF and carbonation progress. Another distinctive aspect of MC treatment was the production of a greater proportion of metastable CC characterized by reduced crystalline size, which was attributed to modifications in the carbonation environment and the structural alterations induced by mechanochemical effects. Moreover, the precipitation of silica gels commenced at approximately 4 min in the MC process, a notably earlier onset when compared with wet carbonation; additionally, a greater abundance of silica gels was observed in the current MC procedure, resulting from the higher carbonation degree caused by mechanochemical effects. The encouraging conclusions in the present work validated the feasibility of producing carbonated RCF more efficiently and paved the way for future industrial practice.

Bio-Composite Films Based on Carboxymethyl Chitosan Incorporated with Calcium Oxide: Synthesis and Antimicrobial Activity.

The utilization of biopolymers incorporated with antimicrobial agents is extremely interesting in the development of environmentally friendly functional materials for food packaging and other applications. In this study, the effect of calcium oxide (CaO) on the morphological, mechanical, thermal, and hydrophilic properties as well as the antimicrobial activity of carboxymethyl chitosan (CMCH) bio-composite films was investigated. The CMCH was synthesized from shrimp chitosan through carboxymethylation, whereas the CaO was synthesized via a co-precipitation method with polyethylene glycol as a stabilizer. The CMCH-CaO bio-composite films were prepared by the addition of synthesized CaO into the synthesized CMCH using a facile solution casting method. As confirmed by XRD and SEM, the synthesized CaO has a cubic shape, with an average crystalline size of 25.84 nm. The synthesized CaO exhibited excellent antimicrobial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) (>99.9% R). The addition of CaO into CMCH improved the mechanical and hydrophobic properties of the CMCH-CaO films. However, it resulted in a slight decrease in thermal stability. Notably, the CMCH-CaO10% films exhibited exceptional antimicrobial activity against E. coli (98.8% R) and S. aureus (91.8% R). As a result, such bio-composite films can be applied as an active packaging material for fruit, vegetable, or meat products.

Effects of heating media on microstructure and chemical composition of heat-treated Pometia pinnata

Changes of microstructure, crystallization, chemical composition, and equilibrium moisture content (EMC) of heat-treated wood (HTW) were investigated to explore the effects of heating media (saturated steam, superheated steam, air) and heat treatment (HT) temperature on HTWs. The results showed that the saturated steam induced more severe cell wall destruction than the other two media. Although the porosity slightly increased with the increasing HT temperature, superheated steam and air HT still decreased the porosity compared to that of control, whereas saturated steam HT increased the porosity. The HT increased both relative crystallinity and crystal size of HTWs. The increasing HT temperature slightly increased the relative crystallinity but decreased the crystal size. The highest crystallinity (55.0%) was observed after saturated steam HT. Leaching led to the increase of crystal size of HTW treated in saturated steam (about 0.15 nm), while those treated in unsaturated steam and air decreased. The increase in relative amount of lignin and cellulose due to the hemicellulose degradation were the main chemical changes of HTWs. Further lignin condensation reaction only occurred after saturated steam HT. Although saturated steam HT induced increased porosity, its lowest EMC (5.91%) indicated the decrease of hydroxyl groups.

Restructuring of Cu-based Catalysts during CO Electroreduction: Evidence for the Dominant Role of Surface Defects on the C2+ Product Selectivity.

CO is the key reaction intermediate in the Cu-catalyzed electroreduction of CO2 to products containing C-C bonds. Herein, we investigate the impact of the particle size of CuO precursors on the direct electroreduction of CO (CORR) to C2+ products. Flame spray pyrolysis was used to prepare CuO particles with sizes between 4 and 30 nm. In situ synchrotron wide-angle X-ray scattering (WAXS), quasi-in situ X-ray photoelectron spectroscopy, and transmission electron microscopy demonstrated that, during CORR, the CuO precursors transformed into ∼30 nm metallic Cu particles with a crystalline domain size of ∼17 nm, independently of the initial size of the CuO precursors. Despite their similar morphology, the samples presented different Faradaic efficiencies (FEs) to C2+ products. The Cu particles derived from medium-sized (10-20 nm) CuO precursors were the most selective to C2+ products (FE 60%), while those derived from CuO precursors smaller than 10 nm displayed a high FE to H2. As the oxidation state, the particle and the crystallite sizes of these samples were similar after CORR, the differences in product distribution are attributed to the type and density of surface defects on the metallic Cu particles, as supported by studying electrochemical oxidation of the reduced Cu particles during CV cycling in combination with synchrotron WAXS. Cu particles derived from <10 nm CuO contained a higher density of more under-coordinated defects, resulting in a higher FE to H2 than Cu particles derived from 10 to 30 nm CuO. Bulk oxidation was most prominent and stable for Cu particles derived from medium-sized CuO, which indicated the more disordered nature of their surface compared to Cu particles derived from 30 nm CuO precursors and their lower reactivity compared to Cu particles derived from small CuO. Cu particles derived from <10 nm CuO initially displayed intense redox behavior, quickly fading during subsequent CVs. Our results evidence the significant restructuring during the electrochemical reduction of CuO precursors into Cu particles of similar size. The differences in CORR performance of these Cu particles of similar size can be correlated to different surface structures, qualitatively resolved by studying surface and bulk oxidation, which affect the competition between CO dimerization to yield C2+ products and undesired H2 evolution.

Control polarity of gallium nitride on Si (1 1 1) using atomic layer annealing and thermal atomic layer deposition

Ga-polar GaN thin films and N-polar GaN thin films were fabricated by using thermal ALD and plasma assisted ALA processes, respectively. The polarity of GaN wurtzite thin films was determined by cross-sectional STEM analysis of as-deposited films and top-view SEM images after KOH wet-etching. The crystallinity and grain size of thermal ALD GaN were drastically increased with the GaN ALA buffer layer. The ALA Ar plasma pulse in each ALD cycle decreased the oxygen and carbon impurity content and improved the crystallinity of GaN thin films by removing organic ligands. High purity GaN thin films were successfully deposited on oxide-free Si (111) substrate by using the ALA process with 100 ms of TDMAGa with push gas, 3 × 800 ms of N2H4, and 15 s of 25 W ALA plasma pulse with −25 V stage DC bias at 275 °C. The lowest FWHM value (0.59°), smooth surface morphology (RMS=1.0 nm), and 10–20 nm grain size of columnar GaN thin films were obtained by tuning process parameters.

Bio activity testing of SnO2-TiO2 nanocomposite synthesis by chemical methods

In this work, SnO2:TiO2 nano composite with silver dopant have been prepared by chemical route method at preparation temperature 100 ℃ , with 6% Ag ratio. Titanium chloride (TiCl3) has been used as the precursors of TiO2 and tin chloride (SnCl2) were taken as the precursors of SnO2 in the laboratory. The prepared samples were described by FESEM, X-Ray diffraction and uv-visible spectrophotometer. Results show that compared to pure SnO2 and pure TiO2 ,SnO2:TiO2 nano composite calcined 400℃ shows a large surface area. The average crystalline size was estimated from XRD analysis by using Debye-Scherrer’s formula and the result shows that the crystalline size increases from (27.78) nm to (29.2354)nm after adding Ag. Bio activity application of the prepared composite has been tested after immersion SnO2:TiO2 nano composite in the simulated body fluid SBF, the morphology and particle size of the prepared immersed samples have been estimated after 20 days by FESEM images.

Mechanisms of the structures and antioxidant activity of broad bean protein affected by AC electric field: changes in conformation and molecular interaction

SummaryThe hierarchical structure modification and antioxidant traits of broad bean protein (BBP) with low denaturation induced by alternating current electric field (ACEF) were examined. The ultraviolet, Fourier transform infrared, and Raman spectrometry showed that ACEF affected the tertiary and secondary structures of BBP, as evidenced by the significant increase in surface hydrophobicity, more β‐turns and random coils, fewer β‐sheets, and the variation of microenvironments of certain amino acid residues. X‐ray diffractometry revealed that ACEF reduced the relative crystallinity and granular size of BBP, increased lattice spacing, caused the weakening of intermolecular forces, and significantly decreased the compactness of spatial conformations in BBP. Furthermore, the antioxidant capacity of BBP increased following ACEF treatment and was influenced by voltage. This may be due to the BBP structure unfolding and the release of aromatic amino acids.

Preparation and characterization of Ea-AgNPs-Si nanocomposite: investigating it as a poultry reformer, pathogen suppressor, sprouting catalyst and adsorbent

This study synthesizes nano composite (Ea-AgNPs-Si) using Euphorbia antisyphilitica(Ea), employing it as a poultry reformer, sorptive material, pathogen suppressor and sprouting catalyst. Characterization involved XRD, SEM, TEM, Zetasizer, UV-Visible and FT-IR techniques. Ea-AgNPs-Si adopted a face centered cubic arrangement with average crystalline size of 20.34 nm. Zeta potential assessed stability. PDI value of Ea-AgNPs-Si nanocomposite is 1 indicating the polydisperse distribution. SEM revealed flower shape (Ea-AgNPs-Si), ranging 70-100 nm in diameter. The disc diffusion method reveals that EaAgNPs-Si exhibits potent antimicrobial activity at 60 µl against Staphylococcus aureus, Actinomycetes, Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa, attributed to its deep diffusion and release of silver ions and silica. It is unequivocally evident from the data that Langmuir isotherm and Pseudo II order model provides a superior fit approaching R2 value as 0.9972, 0.9461, 0.916, 0.9827, 0.9455 and 0.9534 for LA(I), LA(II), LA(III) describing monolayer chemisorption onto surfaces with uniform adsorption energies than Freundlich, Tempkin and BET models, which is synonymous with the results obtained from R2011a Matlab neuro solution. Through final germination (FG) we concluded that among 130 corriandrum seeds sown,109 sprouted in 20 days. Higher germination index (GI) T2&gt;T4&gt;T1&gt;T3&gt; expedited that Ea-AgNPs-Si shall be used as a nutrient to boost the growth of crops. Ordinarily, it necessitates a span of 45 days for a single batch to attain harvest readiness; however, through our efforts, we have accomplished this feat in a mere 20 days. Henceforth, Ea-AgNPs-Si shall be employed as a Poultry Reformer, Pathogen Suppressor, Sprouting Catalyst and Adsorbent.

Synthesis of ZnO/Poly(Styrene‐co‐Methacrylic Acid) Hybrid Polymer Particles for Enhanced UV‐Visible Photodegradation of Methylene Blue

AbstractIn this study, a series of submicron‐sized functional polymer particles poly(Sty‐co‐MAA) with variable methacrylic acid (MAA) content were prepared by soap‐free emulsion polymerization of styrene (Sty), methacrylic acid (MAA), and ethylene glycol dimethacrylate (EGDMA). The number‐average diameters of polymer particles (Dn) were in the range of 0.11 to 0.19 μm. A decrease in particle size was observed with increasing the molar ratio of MAA comonomer in the recipe. ZnO/poly(Sty‐co‐MAA) hybrid polymer particles were prepared by seeded emulsion copolymerization in presence of zinc oxide nanoparticles (ZnO NPs) as seed particles synthesized using Citrus lemon aqueous leaf extract. Scanning electron microscopy (SEM), transmission electron microsphere (TEM), X‐Ray Diffraction (XRD), and Fourier transformed infra‐red (FT‐IR) analysis were performed to characterize polymer particles. The crystalline size of ZnO NPs and ZnO/poly(Sty‐co‐MAA) hybrid polymer particles calculated from XRD analysis were 20.75 and 29.85 nm, respectively. These hybrid polymer particles were applied as photocatalyst in the photodegradation of methylene blue (MB) dye under UV irradiation, which showed high catalytic activity with degradation efficiency of 85.70 % at room temperature compared to bare ZnO NPs.