Scherrer Equation Research Articles

Morphostructural studies of pure and mixed metal oxide nanoparticles of Cu with Ni and Zn

Nano-scale interactions between pure metal or metal-oxide components within an oxide matrix can improve functional performance over basic metal oxides. This study reports on the synthesis of monometallic (CuO), bimetallic (CuO–NiO) and trimetallic (CuO–NiO–ZnO) oxide nanoparticles (NPs) via the co-precipitation method and investigation of morphostructural properties. All of the synthesized metal oxide NPs were calcined at 550 °C temperature and annealed under vacuum. In this work, we applied Scherrer formula, modified Scherrer equation, Williamson-Hall plots, and Halder-Wagner plots to calculate the average crystallite size. The XRD data analysis showed that average crystallite sizes of the as-synthesized metal oxide phases were between 4 nm and 76 nm and average diameters calculated from SEM image were between 15 nm and 83 nm. The XRD studies also disclosed that average crystallite size and lattice microstrain of the CuO phases remain almost same (43 nm–46 nm and 2.074×10−3 to 2.665×10−3) for pure CuO and mixed CuO–NiO; but in case of mixed CuO–NiO–ZnO it is found to decrease in size to 11 nm where lattice microstrain increases to 9.653×10−3. Line broadening of diffraction peaks from microstrain contribution was between 0.02 and 0.01. Degree of crystallinity (%) of CuO phases found to decrease from 81 to 71. Dislocation density of CuO phases found to increase from 6.63×10−4nm−2 to 12.68×10−3nm−2. X-ray density of CuO phases increased from 6.48 to 6.53 g/cm3. Where this calculated small dislocation density well agreed with the high crystallinity. Crystal structure and specific surface area were determined from lattice constants and X-ray density. These synthesized nanopowders showed the existence of monoclinic, cubic, and hexagonal phases. The obtained NPs of multi-metal oxide explained more than one phases with different size, shape, and morphology at nano scale.

La3+ ion doped Cd0.5C0.5LaxFe2-xO4 nanomagnetic materials for high-frequency device applications

The sol-gel self-combustion technique was applied to form Cd–Co-based La-doped (Cd0.5Co0.5LaxFe2-xO4) spinel ferrite nanoparticles. A series of six samples was synthesized by varying lanthanum content from x = 0.00 to 0.20. The structural characteristics of the prepared nanoparticles were carried out using X-ray diffraction (XRD) analysis. The (311) plane verified that the prepared nanomaterials are in the spinel phase in all observed XRD patterns. The crystallite size for each sample was determined using the Scherrer formula found in the 8.7–17.8 nm range, which is well correlated with the SSP model. The crystallite size decreased while the lattice constant increased from 8.38 to 8.45 Å with increasing La-content. The increasing trend in the bulk density and X-ray density has been analyzed with the effects of La3+ contents. In Fourier-transform infrared spectroscopy (FTIR), the high-frequency absorption band (υ1) was found from 522.15 to 541.06 cm−1, whereas the low-frequency band (υ2) varied from 419.80 to 414.31 cm−1. The surface morphology was carried out by scanning electron microscope (SEM), which positively correlated with XRD analysis. Impedance analyzer (IA) assisted in observing the variations in complex dielectric properties of the compound in the frequency range from 1 MHz to 3 GHz. The dielectric constant and impedance plots depicted that the nano ferrites have good dielectric properties in low-frequency regions due contribution of polarization. While conduction can be made possible in the high-frequency areas as observed through AC conductivity. The electric modulus revealed the relaxation phenomenon at high frequency due to the hopping of electrons at the octa and tetrahedral sites. The magnetic properties were investigated to study the impact of La3+ ion under the applied magnetic field from −15 to 15 kOe. The saturation magnetization, and magnetic remanence were found from 40.6 to 27.7 emu/g and 19.6 to 2.7 emu/g, respectively. The synthesized nanoparticles can be utilized for microwave applications and magnetic storage devices.

التخليق الحيوي لجسيمات الفضة النانوية باستخدام مستخلصات الشاي الأخضر

اصبح تركيب جسيمات الفضة النانوية بالطرق الخضراء بواسطة النباتات شائعًا بشكل متزايد بسبب ملاءمته للبيئة ، وتوفره ، وفعاليته وكلفته القليلة ، ويمكن التعامل معه بأمان ويمتلك تنوعًا واسعًا من المركبات الفعالة ، مثل مضادات الأكسدة و ومركبات مضادة للميكروبات. في الدراسة الحالية ، تم تصنيع جسيمات الفضة النانوية AgNPs باستخدام المستخلصات المائية والميثانولية لأوراق الشاي الاخضر التي اختزلت نترات الفضة, والتي تم توصيفها باستخدام العديد من التقنيات التحليلية مثل القياس الطيفي المرئي فوق البنفسجي (UV-Vis) ، والتحويل الطيفي بالأشعة تحت الحمراء (FTIR) ، والفحص المجهري الذري (AFM) ، وتشتت الأشعة السينية (XRD) وفحص جهد زيتا. أشارت الملاحظة البصرية إلى أن لون نترات الفضة المائية قد تحول بعد المعاملة بمستخلصات الأوراق وتأكد ذلك بواسطة أطياف UV-Vis. فضلا عن ذلك ، أظهر تحليل AFM أن الجسيمات كانت كروية الشكل ، مفردة أو في مجاميع بمتوسط ​​أحجام 108.3 و 84.76 نانومتر للمستخلصات المائية والميثانولية على التوالي. كذلك, أكدت تقنية XRD الطبيعة البلورية للجسيمات النانوية, وتم تقدير متوسط ​​الحجم وفقًا لمعادلة شيرير اذ بلغت 61.24 و 99.66 نانومتر للمستخلصات المائية والميثانولية (CANPs) على التوالي. بالإضافة إلى قيم زيتا المحتملة كانت-30.31 و -32.33 مللي فولت للمستخلصات المائية والميثانولية CANPs على التوالي.

Characterization of TiO2 nanoparticles for nanomaterial applications: Crystallite size, microstrain and phase analysis using multiple techniques

This study aimed to verify the suitability of TiO2 nanoparticles as nanomaterials in terms of crystallite size, microstrain and phase. The TiO2 nanoparticles were tested experimentally in suspensions of mono ethylene glycol and distilled water (MEG-DW) at ratios of 10:90, 25:75, and 40:60. The nanoparticles were dispersed in the base liquid via a two-step process, resulting in the formation of TiO2-3%/MEG-10, TiO2-3%/MEG-25, and TiO2-3%/MEG-40 nanofluids. The results revealed average crystallite sizes of approximately 20.10, 22.10, and 39.6 nm for the three nanofluid samples, as determined by the Scherrer equation, Williamson–Hall (W–H) plot, and TEM-ImageJ software. These results confirm that the TiO2 nanoparticles meet the nanomaterial criteria with a sub-100 nm size. The microstrain analysis yielded values of 0.000020, 0.000299, and 0.001386 for the three samples and further investigation confirmed the presence of rutile. The high-temperature stability of the rutile phase makes the TiO2 nanofluids suitable for use in industrial heating systems.

Facile one step microwave assisted biofabrication of Fe2O3 NPs: potential application as solar light-driven photocatalyst in the photodegradation of acridine orange

ABSTRACT The utilisation of a recently developed green approach for synthesising iron oxide nanoparticles (Fe2O3NPs) is highly promising, given its low toxicity and environmentally benevolent attributes. In this investigation, Fe2O3 NPs were produced through the utilisation of ferric chloride hexahydrate, incorporating Permelia perleta ;(lichen) extract under standard atmospheric conditions. The development of Fe2O3 NPs was verified through a systematic characterization process by employing UV FTIR, XRD, and FE SEM studies. The average crystallite size of the developed sample was found to be 20 nm determined by using Debye – Scherrer equation. The efficacy of the developed Fe2O3 NPs as a photocatalyst in eliminating acridine orange was evaluated, highlighting key factors such as catalyst dosage, initial dye concentration, and pH. Augmenting the quantity of Fe2O3 NPs amplified the decolourisation of the dyes, reaching a peak of 70% dye degradation at pH 2 after 2 h with a catalyst dose of 0.9 g/L. The most pronounced effect was observed against Bacillus subtilis (22 mm), whereas the least impact was noted for Pseudomonas aeruginosa (14 mm). Furthermore, the developed nanoparticles underwent antioxidant activity analysis, revealing that 1 gm of nanoparticles possesses antioxidant activity equivalent to 4.22 mg of ascorbic acid.

Preparation and structure investigation of polyethylene terephthalate polyester reinforced Ni0.5Zn0.5Fe2O4 nanoparticles for gamma ray shielding performance

Defects of high atomic materials gamma-ray shielding such as low chemical stability, low mechanical properties, and heaviness lead us to investigate other light and flexible materials such as polymers. Polymer-doped nanosized materials are the most frequently examined materials. In this study, polyethylene terephthalate [(C10H8O4)n] was doped with Ni0.5Zn0.5Fe2O4 nanoparticles up to 40 wt% (0.0, 10.0, 20.0, 40.0 wt%) prepared by Sol–Gel auto-combustion method with the help of Gelatin. The polyester/Nanofiller composite structures were identified using x-ray photoelectron spectroscopy, x-ray diffraction, Scanning, and Transmission electron microscope as well as density measurements. x-ray photoelectron spectroscopy confirmed the successful doping of nanofiller in the polyester structure as Zn signals appear in the atomic composition and Fe signals appear in the deconvolution of the peaks. x-ray diffraction, transmission, and scanning electron microscope display the same result. x-ray diffraction graph information with the Scherer equation offered the crystal size of the composite (26 nm). Polyester/nanofiller samples were scanned against gamma-ray and experimental shielding factors were computed using a narrow beam transmission technique with sodium iodide detector and two-point sources Cs-137 and Co-60. Experimental Linear and mass attenuation coefficient values swelled as percentages of nanofiller increased in the polyester structure. Experimental Mass attenuation values were compared with theoretical ones estimated from XCOM and Physics-X programs. The difference between them does not exceed 12% which is acceptable as the x-ray photoelectron spectroscopy atomic composition utilized in the theoretical data calculation does not reveal Ni signals. This may occur at the depth of the composite structure. Finally, the half-value layer, the Tenth value layer, and the Mean free path are determined experimentally, and their values are reduced as the nanofiller doping percentage rises in the structure. This result confirms the efficiency of nanofiller addition to the polyester structure to attenuate gamma-ray.

Facile synthesis of co-axially electrospun Co-C nanofibers and their ferromagnetic behavior

We describe a simple co-axial electrospinning approach followed by a carbonisation process to create cobalt-carbon (Co-C) nanofibers that are then thoroughly analysed using various techniques. X-ray diffraction measurements showed the creation of pure crystalline cobalt with face-centered cubic (fcc) structure, and average crystallite size was determined using the Debye–Scherrer formula. The average crystallite size has been calculated to be in the range of 10 − 15 nm. According to the Raman investigation, all Co-C nanofibers have an amorphous carbon structure with little graphitic behaviour. Field emission scanning electron microscopy was used to determine the shape and average diameter of electrospun nanofibers. The field-dependent magnetic characterisation demonstrated a satisfactory ferromagnetic behaviour with maximum saturation magnetisation values of 10, 10.2, and 11.2 emu/g for Co12.5-C sample at 300, 100, and 5 K, respectively. Compared to bulk cobalt, the produced Co-C nanofibers have a high coercivity value. With average crystallite size, the coercivity varies. Again, magnetisation versus temperature measurements have supported the existence of ferromagnetism because there is no evidence of blocking temperature or any transitional behaviour below 300 K. As a result, applications for microwave absorption, catalysis, and several magnetic recording devices can benefit from the coupling of ferromagnetic properties with carbon nanofiber materials.

A study on the oxidative property using thermogravimetric analysis of NiO nanoparticles prepared by a simple wet chemical method

Nanosized NiO particles were synthesised by chemical co-precipitation technique and the particle has been characterized morphologically, elementally, structurally and thermally using High Resolution Scanning Electron Microscopy (HR-SEM), Energy Dispersive X-ray Spectroscopy (EDAX), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD) and Thermogravimetric Analysis (TGA). A green precipitated Nickel Oxide Nanoparticles (NiO NPs) was prepared and the size of the particle was found to be 45 nm and the presence of Ni and O elements were confirmed using the elemental analytic tools like EDX and FTIR in which the existence of water molecules was confirmed from the absorption spectrum. The generated sample's crystal structure was face-centered cubic, and Scherer's equation was used to compute its size, which was found to be 43 nm. Crystal characteristics including crystal parameters (a), interatomic distance (dh,k,l), atomic radius (r) and cell volume (Vc) were also calculated. The weight loss observed from TGA curve signifies the oxidative property of NiO NPs and there is a steady increase in the weight difference versus time difference. The calcination temperature of NiO was determined to be 700⁰C via analysis at the TGA curve's peaks. The activation energy (Ea) was determined using Coats-Redfern method by solving the slope of the graph between log[−log(1−α)T2] and 1000T. With respect to its highly effective capacity, which can be seen when treating with an increase in temperature, NiO may be used as an oxidising and reducing agent in oxidation and reduction processes.

Fabrication of single-step novel synthesis of ZnCd(S0.5Se0.5)2 thin films for photoelectrochemical (PEC) cell application

In our study, we use a new method called the arrested precipitation technique (APT) to create CdZn(SSe)2 (CZSS) thin films. We obtain samples at different deposition times, ranging from 2.5 to 4 h, and analyze the effects of deposition time on the opto-structural, morphological, compositional, and photoelectrochemical (PEC) solar cell properties. As a result, we find that the band gap energy increases from 2.366 to 2.60 eV with prolonged growth time, as shown by UV–Vis spectra. X-ray diffraction (XRD) analysis confirms that the crystal structure is hexagonal, with the crystallite size increasing from 76 to 93 nm. The dislocation density and microstrain, determined by the Scherrer formula, decrease from 1.72 to 1.14 lines m−2 and from 4.75 × 10−3 to 3.87 × 10−3 (lines m−2), respectively. These results are validated using the Williamson-Hall (WH) plot and size-strain plot. The average grain size, evaluated using the standard scale bar method in scanning electron microscopy (SEM), ranges from 80 to 150 nm across CZ1 to CZ4 samples. Transmission electron microscopy (TEM) images of CZ4 and CZ2 reveal particle sizes of 101 nm and 87 nm, respectively, while selected area electron diffraction (SAED) patterns confirm the polycrystalline nature of the material. Energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) analyses confirm the presence of Cd, Zn, S, and Se elements in their intended stoichiometry. Notably, CZSS photoelectrodes deposited over 4 h show better performance in Photoelectrochemical cells (PEC), achieving the highest photoconversion efficiency (ɳ) at 2.33 %, as evidenced by J-V measurements.

Sustainable and Environmentally Friendly Microwave Synthesis of Nano-Hydroxyapatite from Decarbonized Eggshells.

The sustainable microwave (MW) synthesis of hydroxyapatite (HAp) from decarbonized eggshells was investigated. Decarbonization of eggshells, as a natural source of calcium carbonate (CaCO3), was carried out in the current study at ambient conditions to reduce the footprint of CO2 emissions on our environment where either calcination or acidic direct treatments of eggshells produce CO2 emissions, which is a major cause for global warming. Eggshell decarbonization was carried out via the chemical reaction with sodium hydroxide (NaOH) alkaline solution in order to convert eggshell waste into calcium hydroxide (Ca(OH)2) and simultaneously store CO2 as a sodium carbonate (Na2CO3) by-product which is an essential material in many industrial sectors. The produced Ca(OH)2 was mixed with ammonium dihydrogen phosphate (NH4H2PO4) reagent at pH~11 before being subjected to MW irradiation at 2.45 GHz frequency for 5 min using 800 Watts to prepare HAp. The prepared Nano-HAp was characterized using X-ray diffraction (XRD) where the crystal size was ~28 nm using the Scherrer equation. The elongated rod-like nano-HAp crystals were characterized using scanning electron microscopy (SEM) equipped with dispersive energy X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). MW synthesis of decarbonized eggshells is considered as a sustainable and environmentally friendly route to produce promising bioceramics such as nano-HAp. Concurrently, decarbonization of eggshells offers the ability to store CO2 as a high value-added Na2CO3 material.

Magnetic, Electric, and Antimicrobial Properties of Chromium‐ Doped Cobalt Zinc Ferrite Nanoplates

AbstractIn the present work, Co0.5Zn0.5CrxFe2‐xO4 (CZFCO) (x=0.0, 0.1, 0.2, 0.3, 0.4, and 0.5) has been successfully driven from self‐ignited sol‐gel method, using citric acid as a chelating agent. The powder XRD patterns are confirming the formation of single‐phase cubic crystallographic structure with satisfying the Fd‐3m space group. The Rietveld refinement process is carried out to obtain the structural information, including lattice parameters, cell volume, and bond length. Crystallite size and micro‐strain values are found by the Debye Scherrer formula as well as by HR‐TEM the particle size is shown at about 7.86 nm and the presence of two distinct lattice fringes. The SEM digital images display soft wart grains nature, where the majority of grains are forming a dense agglomerate nature with nano plate texture. EDS spectra reflect the presence of all the elements without impurities. The formations of spinel ferrite and metal‐oxygen bond were approbated by FT‐IR Spectra. Further, RT UV‐Vis spectra (DRS) show a decrease in the optical band gap from 1.56 eV to 1.46 eV. The magnetic properties indicate soft ferromagnetic behaviour and as increasing Cr dopant saturation magnetization and coercivity significantly decrease while in the case of X=0.5 suddenly enhanced the Ms, this well corroborates with cation distribution. X‐ray photoelectron spectroscopy (XPS) technique has confirmed the presence of all elements and shows the valance of the Cr is +3 and +2 states at respected octahedral and tetrahedral sites. RT dielectric studies firmly agreed with the Maxwell‐Wagner type of polarization following Koop's theory. RT Impedance spectra suggest consent of the Debye type of relaxation and the Cole‐Cole map shows semi arc‐shaped curve fitted with Gaussian distribution. The imaginary and real parts of the relative permeability of frequency‐dependent curves decayed and firmly showed the favourable character of electric properties. Finally, all the antimicrobial activity results suggested the potential utility of derived compounds as antibacterial agents.

Intrinsic pseudocapacitive enhancement of NiCo2O4/activated carbon composites for high-performance supercapacitors

The high electrical conductivity and capacitance of NiCo2O4 have made it a promising electrode material for supercapacitors with advantages in rapid energy storage, long cycle life, and potential for flexible applications. Nickel Cobaltite Oxide (NiCo2O4) nanoflakes were successfully synthesized by the sol–gel method. The composite Activated carbon was made from waste coconut shells. The X-Ray Diffraction (XRD) pattern matches with the standard values, the crystallite sizes were found to be 7 nm using the Debye Scherrer formula. FTIR reveals the molecular bond of (NiCo2O4) NFs and their composites peak at 541 cm−1 and 552 cm−1 confirms the formation of NiCo2O4 Metal oxides. From optical absorption studies, it is found that both NiCo2O4 NFS and NiCo2O4/AC composites have maximum absorption throughout the UV region. The bandgap increases from 1.26 eV to 1.34 eV on adding AC composites to NiCo2O4 NFs. Scanning Electron microscopy (SEM) shows the formation of NiCo2O4 nanoflakes. The activated carbon has high surface area with micropores, confirmed by BET analysis. Cyclic Voltammetry (CV) analysis shows that NiCo2O4/AC composite has a more specific capacitance at low scan rate of 10 mV/s, which is more than NiCo2O4 NFs. Both the samples recorded high specific capacitance values of 142 F g−1 and 192 F g−1 at the current density of 1 A/g using GCD. From this NiCo2O4/AC composites may be a high-performing capacitor with intrinsic pseudocapacitive behaviour compared to NiCo2O4 NFs which has extrinsic pseudocapacitive behaviour.

Silver‐coated copper nanocomposites synthesis using the essence of Foeniculum vulgare mill and estimation of its antibacterial and cytotoxicity effects

AbstractThe Cu3.96Ag0.04 nanoparticles were synthesized using the essence of Foeniculum vulgare Mill for the first time. The particles were fully analysed by conventional characterization methods such as powder X‐ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), dynamic light scattering (DLS). The results have shown the crystal structure of silver copper particles and the crystallite size obtained by the Scherer equation was 23.2 nm. The TEM images interestingly displayed the formation of nanorods in the solid phase with nearly 5 nm widths and different lengths up to 100 nm. The hydrodynamic size is also compatible with the solid phase and crystallite sizes. Biologically, the particles were tested against infective gram negative and gram positive bacteria. The synthetic NPs show strong antibacterial properties against gram negative bacteria. Also, the synthesized nanoparticles had an inhibitory effect on the growth of cancer cells, which was dose‐ and time‐dependent.

Structural and Electrical Properties of Li Substituted Mg Nano Ferrites: Prepared by Citrate-gel Auto Combustion Method

LixMg1−xFe2O4 where x=0.0to0.5with0.1 nano ferrites were synthesized by citrate gel auto combustion. Using a field-emission scanning electron microscope (FE-SEM) and the X-ray diffraction technique, their structural and topographical studies were examined. The prepared nano ferrites’ single-phase cubic spinel along the Fd3m space group is confirmed by the structural investigation. The synthesized samples were found to have a crystalline size of 20–26 nm, as determined by the Debye–Scherrer formula. Lattice parameter variation observed for the samples indicates dopant atoms into a crystal lattice can also lead to changes in the lattice constant. FE-SEM images revealed the clear grain and grain boundaries with agglomerated structure and it varied between 33.6 nm-24.4 nm. Two bands observed in Fourier transform infrared spectroscopy illustrates the M-O band in tetrahedral and octahedral sites. Dielectric parameters of the sample observed by LCR meter. Single semicircle behavior observed in impedance spectra. Dielectric constant and dielectric loss decreased as increasing frequency explained by Koop’s theory of mechanism. AC conductivity increasing trend observed with frequency, mobility of charge carrier active at high frequency domain.

Synthesis and Characterization of Barium Hexagonal Ferrite (BaFe12O19)

Barium Ferrites is a good class of electrical material due to its high resistivity. It is mainly used in electronics and telecommunication industry due to their novel electrical properties. We have synthesized barium hexagonal ferrite (BaFe12O19) by solid state reaction method. The prepared precursor was calcined at temperature 750°C and characterized by FTIR, XRD and SEM. X-ray diffraction analysis confirmed the single-phase formation of BaFe12O19. Using the Debye Scherrer formula, the crystallite size of BaFe12O19 was calculated, and the average particle sizes were 26.52 nm, 27.17 nm, 19.17 nm and 23.67 nm. The result confirms that barium ferrite powder has a constant size of less than 30 nm. Four peaks at 2θ values of 35.52, 43.22, 57.21 and 62.84 degrees, corresponding to (110) (111) (210) and (211) planes of Barium ferrite have been observed. The FTIR spectra showed important signature absorption spectra of hexaferrite at 314 cm−1, 499 cm−1 & 628 cm−1. These peaks confirm the formation of barium hexaferrites. The SEM images of barium hexaferrite at 750°C showed large number of vertically grown barium hexaferrite nanorods with a grain size between 110 nm to 130 nm. Thus, barium ferrite is a good candidate in the use of electronics and communication sector.

Influence of NaOH Concentration on Structural, Morphological, Optical, and Electrical Characterization of Perovskite Sodium Bismuth Titanate Prepared by Hydrothermal Method

The hydrothermal method successfully prepares a lead-free sodium bismuth titanate (NBT) perovskite film. The prepared films were studied structurally, and morphologically using X-ray diffraction, and field-emission scanning electron microscopy (FESEM), respectively. Varying the concentration of NaOH showed a noticeable effect on the properties studied. Good crystallization of NBT perovskite films without impurities was obtained at 18 and 20 M concentrations, where the crystalline size was 14 nm according to the Scherer equation. Also, when varying the concentration of NaOH, a similar film thickness was obtained through a cross-section of the FESEM images. It was observed that there was a difference in the intensity of the peaks of the photoluminescence spectra of the prepared films with a change in the concentration of NaOH, which confirms a change in the concentration of oxygen vacancies. The activation energy of the prepared films was deduced from the Arrhenius plot, as it showed small values in the films prepared with a low concentration of NaOH. The results showed that the maximum value of mobility of NBT films was at 20 M of NaOH concentration through the Hall Effect.

Characterization and antimicrobial Properties of Cotton Fabric Loaded with green Synthesized Silica Nanoparticles

During the past decade, improvement in the functionality of textile materials has become an important research field due to their significant health and safety benefits. Here we report, simple and cost-effective green synthesis of silica nanoparticles from fibrous residue of sugarcane bagasse followed by investigating the applicability on cotton fabric. The characteristics of synthesized nanoparticles were determined by techniques including FTIR (exhibited characteristic peak at 791.01 attributed to vibration of Si-O and the absorption band at 1072.48 cm-1 owing to asymmetric vibration of Si-O-Si confirming the formation of SNPs), SEM (40±2nm), and XRD (Examined spectra with JCPDS 36-1451 indicate well-defined peaks of Silicon Oxide). Debye Scherrer equation was used to calculate the mean crystallite size (19.79 nm) of powder Silica NP sample at the full width half maximum (FWHM) of the diffraction peaks of 2Ɵ positions. Applicability of synthesized nanoparticles was determined by assessing thermal stability and antimicrobial property of treated and untreated cotton fabric. It was observed that silica nanoparticles coated fabric showed substantial thermal stability at 1 % Silica NPs comparatively treated with 2% and 3% silica NPs due to clustering phenomena. Antimicrobial property, confirmatory test as positive control of treated fabric shown substantial increased in antibacterial activity in solutions containing silica NPs as compared to the ethanol solution. Moreover, 76 green profiling score of synthesized method was evaluated by Analytical Eco-Scale tool.

Tunning of catalytic performance in coupling, reduction and oxidation of hydrothermal assisted mixed metal oxides of Pd and Cu loaded over mesoporous nanostructure titania coated N‐doped silica using rice husk

Silica–titania‐based mesoporous nanomaterials due to their widespread availability and inexpensive cost have been employed in an extensive range of applications, including heterogeneous catalysis. This research article discusses the hydrothermal synthesis of highly efficient heterogeneous nanocatalyst, that is, mixed metal oxides of Pd and Cu immobilized over silica–titania mesoporous nanostructure and its application in coupling, reduction and oxidation reactions. It was characterized by Fourier transform infrared spectroscopy (FTIR), powder X‐ray diffraction (P‐XRD), field emission gun–scanning electron microscopy (FEG‐SEM), energy‐dispersive X‐ray analysis (EDX), high‐resolution transmission electron microscopy (HR‐TEM), X‐ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), UV–visible spectroscopy (UV–VIS), Brunauer–Emmett–Teller (BET), X‐ray resonance fluorescence (XRF), photoluminescence (PL) and inductively coupled plasma–atomic emission spectroscopy (ICP‐AES) studies to assemble information regarding various structural features. XPS analysis successfully confirmed the presence of mixed oxidation state of Pd and Cu, that is, Pd(0), Pd(II), Cu(0), Cu(I) and Cu(II) over the nanocatalytic support. TEM images showed that the PdCu alloy had spherical shape with average size between 3 and 4 nm. BET analysis indicated that the catalyst has specific surface area of 57.296 m2 g−1 with average pore diameter of 1.84 nm. The results of TGA and DTA analysis demonstrated that the maximum temperature up to which PC‐TNS can catalysed organic reactions was 170°C. The average crystallite size of PC‐TNS was came around 16.08 nm calculated using Scherrer's equation. Moreover, synthesized heterogeneous nanocatalyst was highly recyclable and FEG‐SEM, P‐XRD and XPS findings confirmed the structural disruption after sixth or seventh catalytic run resulted in decrease in yield of products. In general, nanocatalysts can be convincingly more superior to other heterogeneous nanocatalyst due to their unique features such as high specific surface area, high reusability, high reactivity, high product yield and environmentally friendly.

Synthesis, Structural Characterization and Temperature Effects on Chloroform Vapor Sensing Properties of ZnO Nanocrystals

In this study, nanocrystalline ZnO were synthesized onto glass substrates by using sol-gel method. Structural characterizations were performed by XRD, SEM and AFM techniques. Potential application of nanocrystal ZnO as chloroform sensor was investigated. Response of the fabricated thin films of the ZnO nanocrystals towards chloroform vapor was investigated depending on gas concentration (750-15000 ppm) between the temperatures of 22‒150 ºC in nitrogen ambient. Gas flow rates were controlled by using flow controller and flow meters. All the measurement system was computerized. XRD results revealed that thin film of the ZnO nanocrystals on the glass substrate was in crystal form and can be characterized by 036-1451 JCPDS number. Crystallite sizes of the ZnO nanocrystals were determined both by SEM images and the Scherrer equation. The crystallite sizes were calculated between 27.9 – 50.4 nm using the Scherrer equation. The sensors showed reversible response towards the chloroform vapor in the measured temperature and gas concentration range. Response time and sensitivity values of the sensors towards the chloroform vapor were also calculated. The increase in temperature caused to increase in sensitivity values. The best sensitivity values were obtained at 150 ºC.

THE EFFECT OF THE CHOICE OF THE STARTING MATERIAL ON THE PHASE COMPOSITION AND PHASE STABILITY OF ZRO<sub>2</sub> PARTICLES SYNTHESIZED BY THE HYDROTHERMAL METHOD

In this work, the phase composition, microstructure and phase stability of zirconium dioxide samples obtained by hydrothermal synthesis from various starting materials were investigated. It was found that when using ZrOCl2·8H2O as a starting material, zirconium dioxide particles containing monoclinic and tetragonal (cubic) phases are formed, at the same time, when using ZrO(NO3)2·2H2O as a starting material, only the monoclinic phase was identified in the samples. The CSR dimensions calculated using the Scherrer equation are in the range from 9 to 40 nm. Analysis of SEM images of experimental samples showed that nanoparticles form conglomerates with sizes of several microns. A study of the phase stability of the t, c – ZrO2 phase from temperature exposure showed that t, c – ZrO2 is a metastable phase with CSR sizes up to annealing of 10 nm. With an increase in the annealing temperature, the metastable tetragonal (cubic) phase of ZrO2 gradually transforms into a monoclinic one, due to the processes of minimizing surface energy and particle proliferation, as well as sintering conglomerates into larger monolithic particles.