Ultraviolet-visible Spectroscopy Techniques Research Articles

Synthesis, characterization, in vitro and in silico studies of N, N-dimethyl phenyl chalcone-Schiff’s base hybrid

Three dissimilar N, N-dimethylphenyl chalcone Schiff's base hybrids (CSBHs) were synthesized and characterized by nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared (FT-IR) and ultraviolet-visible spectroscopic techniques by the theoretical as well as investigational methods. The molecular weights of the CSBHs were also confirmed by the Electrospray ionization Mass technique. The in vitro antidiabetic, anti-inflammatory and cytotoxicity were tested for the CSBHs using α-amylase inhibitory and protein anti-denaturation methods. The CSBHs showed good antidiabetic and anti-inflammatory activities and the percentage of inhibitions is nearer to standard drugs acarbose and diclofenac sodium. The molecular docking studies for CSBHs were investigated and their docking results are superior and also density functional theory method are performed for CSBHs to support biological and molecular docking results. The CSBHs showed very good hydrogen bonding interactions with amino acid residues of the enzymes and the CSBHs showed lower band gap and higher electrophilicity index values. In addition, (ADMET) Absorption, Distribution, Metabolism, Excretion and Toxicity study and Protox-II toxicity predictions were performed to check the pharmacological properties of CSBHs.

Efficient Electrochemical Sensing of Chlorpromazine with a Composite of Multiwalled Carbon Nanotubes and a Thiacalix[4]arene-Based Metal-Organic Framework.

Chlorpromazine (CPMZ) is a representative drug for the treatment of psychiatric disorders. Excessive use of CPMZ could result in some serious health problems, and therefore, construction of a sensitive electrochemical sensor for CPMZ detection is greatly significant for human health. Herein, a feasible electrochemical method for the detection of CPMZ was provided. To design a suitable electrode surface modifier, a new two-dimensional (2D) thiacalix[4]arene-based metal-organic framework was designed and synthesized under solvothermal conditions, namely, [Co(TMPA)Cl2]MeOH·2EtOH·2H2O (Co-TMPA). Afterward, a series of composite materials was prepared by combining Co-TMPA with highly conductive carbon materials. Markedly, Co-TMPA/MWCNT-2@GCE (GCE = glassy carbon electrode, MWCNT = multiwalled carbon nanotube) exhibited the best electrocatalytic performance for CPMZ detection due to the synergistic effect between MWCNT and Co-TMPA. Particularly, it featured a low limit of detection (8 nM) and a wide linear range (0.05 to 1350 μM) in quantitative determination of CPMZ. Meanwhile, the sensor possessed excellent stability, selectivity, and reproducibility. Importantly, Co-TMPA/MWCNT-2@GCE was employed to analyze CPMZ in urine and serum with satisfactory recoveries (98.87-102.17%) and relative standard deviations (1.44-3.80%). Furthermore, the electrochemical detection accuracy of the Co-TMPA/MWCNT-2@GCE sensor was verified with the ultraviolet-visible spectroscopy technique. This work offers a promising sensor for the efficient analysis of drug molecules.

Photocatalytic properties of ZnO semiconductor nanoparticles green synthesized employing Ipomoea stans leave extracts

One of the biggest problems in the ecosystem is wastewater contaminated with industrial dyes. These pollutants have a very stable chemical structure, which causes complicated removal. However, a possible alternative for wastewater treatment is zinc oxide semiconductor nanoparticles (ZnO NPs). The approach of this study was the implementation of a green synthesis methodology for the obtention of ZnO nanoparticles employing Ipomoea stans (TV) leaves as extracts. The properties of the ZnO nanoparticles synthesized at 1 %, 2 %, and 4 % w/v (weight/volume) concentration of the extract were obtained from the characterization using different techniques. The FTIR analysis determined the presence of the active functional groups attached to the surface, which capped and stabilized the ZnO NPs; a band located in the range of 500-390 cm−1 confirms the presence of the Zn–O bond. The UV absorption spectra of all ZnO NPs samples were determined by executing the ultraviolet–visible spectroscopy technique, with a characteristic signal located at ∼370 nm and energy gap values between 3.036 eV and 3.101 eV. In addition, XRD patterns determined the average crystallite sizes to be 30.78 nm for ZnO-TV 1 %, 18.68 nm ZnO-TV 2 %, and 11.96 nm ZnO-TV 4 %, respectively. Furthermore, the results from transmission electron microscopy (TEM) displayed the following values of mean particle size of 21 nm, 24.4 nm, and 10.16 nm for ZnO-TV 1 %, ZnO-TV 2 % and ZnO-TV 4 % with S.D. 9.10, 12.5 and 3.6. Finally, the photocatalytic activity was evaluated utilizing the industrial dyes Methyl Orange, Methylene Blue, Rhodamine B, Malachite Green, and Congo Red. Obtaining outstanding results in the degradation of all industrial dyes. All syntheses achieved degradation greater than 91 % for methyl orange, methylene blue, and rhodamine B.

Study of optical, structural and radiation shielding properties of (55 − x)TeO2–20ZnO–25B2O3–xEr2O3 glass matrix

Abstract Erbium doped zinc boro-tellurite (EZBT) glass samples with molar composition of (55 − x)TeO2–20ZnO–25B2O3–xEr2O3 (x = 0.0, 0.5, 1.0, 1.5 and 2.0 mol.%) were prepared by a conventional melt quenching technique. The prepared samples were characterised using X-ray diffraction, Fourier transform infrared spectroscopy and ultraviolet–visible spectroscopy techniques to investigate the structural, optical and dielectric properties. To study the radiation shielding capabilities, the parameters such as mass attenuation coefficient (μ m), half-value layer (HVL), effective atomic number (Z eff) etc., were evaluated using WinXCom software. Judd–Ofelt analysis was carried out to determine the intensity of electronic transitions and other radiative transition parameters within the 4f shell of erbium ions. The μ m values in a range of (108.5–0.03) cm2 g−1 for energy range (0.01–10) MeV were obtained for 2.0 mol.% erbium-doped tellurite glass matrix. The μ m and HVL values were also compared with conventionally used ordinary concrete and specific lead borate glass at certain energies. The detailed investigation of this current EZBT glass matrix is very useful in the specific optical and radiation shielding applications of this EZBT glass.

Facile synthesis, Spectral investigation, in vitro and in silico studies of Thiophenecarboxamide-α,β-unsaturated ketone hybrids

Thiophenecarboxamide-α,β-unsaturated ketone (TCKs) hybrids were synthesized and scrupulously characterized by nuclear magnetic resonance spectroscopy (NMR) by the theoretical and experimental methods, Electrospray ionization mass (ESI-MS), Fourier transform infrared (FT-IR) and ultraviolet-visible spectroscopic techniques by experimental and theoretical methods. The anti-inflammatory and antidiabetic activities were tested for TCKs using protein anti-denaturation and the α-amylase inhibitory methods respectively. The molecular docking studies for TCKs were inspected and data were supported by their molecular parameters that were determined using density functional theory calculations (DFT). The obtained results of TCKs showed a lower band gap and higher electrophilicity index values. Molecular docking studies were investigated against the α-amylase and cyclooxygenase enzymes to compare the tentative results. The TCKs showed very good hydrogen bonding interactions with amino acid residues of the enzymes. In addition, ADMET study, Protox-II toxicity predictions were performed to check the pharmacological properties of TCKs.

Oxidation of aspartic acid with molybdenum-oxime-ligand framework in acidified-aqua and interfacial active media: Menger-Portnoy kinetic model

Understanding the chemistry of amino acids as the pillar of the proteins framework is vital when elucidating their mechanisms. The oxidation of aspartic acid (ASP) with molybdenum-oxime-ligand framework (MOL) is executed with the ultraviolet–visible spectroscopy technique, and the Menger- Portnoy model is generated in order to give more explanation to the empirical kinetic data. The aspartic acid’s oxidation is inert salt (NaCl) and counter-ion effects dependent. Deprotonation of the ASP countered the accelerating effect of the proton supplied by the acid (HCl). The mole ratio shared between the ASP and molybdenum-oxime-ligand framework is singlet with the generation of aldehyde malonic radical and carbon dioxide evolution. The kinetic order in [ASP] and [MOL] is singlet, and the thermodynamic activation parameter (ΔS‡ = −134.34 Jmol−1K−1) accounts for the solvation orderliness within the activated ASP-MOL specie at the transition state and the maintenance of MOL structural integrity. The interfacial active specie (sodium dodecyl sulphate, SDS) proves useful in catalysing ASP oxidation, and it is reinforced by Menger-Portnoy kinetic parameters.

Complex dielectric, electric modulus, impedance, and optical conductivity of Sr3−x Pb x Fe2TeO9 (x = 1.50, 1.88 and 2.17)

Abstract Sr3−x Pb x Fe2TeO9 (x = 1.50, 1.88 and 2.17) were synthesized in polycrystalline form via the solid-state reaction route in air, and were studied at room temperature using powder X-ray diffraction and ultraviolet visible spectroscopy techniques. The crystal structures were resolved by the Rietveld refinement method; x = 1.50 and 1.88 adopt a tetragonal phase (space group I4/mmm) while x = 2.17 adopts a hexagonal phase (space group R 3 ̄ $\bar{3}$ m). The direct bandgap energy (E g) of ∼1.89 eV for (x = 1.50), ∼1.87 eV for (x = 1.88) and ∼1.74 eV for (x = 2.17) was estimated from the Tauc plots of (αhʋ)2 versus photon energy. The Urbach energy (E U) was determined from the plots of logarithmic absorption coefficient versus hυ. Plots of the incident photon energy dependence of optical parameters such as refractive index, extinction coefficient, real and imaginary parts of the dielectric function, dielectric loss, real and imaginary parts of the complex optical conductivity, linear and nonlinear optical susceptibilities, real and imaginary parts of the electric modulus, real and imaginary parts of the impedance were obtained by means of ultraviolet visible spectrophotometer experiments. Additionally, the estimated values of the single oscillator energy, dispersion energy, static refractive index and high-frequency dielectric constant were obtained from the linear portion of the (n 2 − 1)−1 versus (hυ)2 plots using the Wemple–DiDomenico model.

Facile synthesis and optimization of CuONPs using Illicium verum & Polianthes tuberosa and their anticancer activity

• The Copper oxide nanoparticles were successfully synthesized using extract of Star anise and Polianthes Tuberosa. • The plant material used was successfully acted as reducing agent, stabilizing and capping agents. • Synthesized Copper oxide nanoparticles were characterized by FT-IR, Ultraviolet–visible SEM & XRD techniques. • The size of the Copper oxide nanocrystals was 25.40 nm and 32.7 nm structure was monoclinic end-centered. • SEM analysis results sphere like shape and morphology for Copper oxide nanoparticles. • Showed significant anticancer activity against MM2 cancer cell line. Cancer has considered the second most deadly disease and causes more deaths in human beings without any age factors. Nowadays research is going on finding a potential drug to cure cancer. Especially nanoparticles are used for this process. In our research, we prepared CuONPs using an extract of Illicium verum and Polianthes tuberosa. Synthesized CuONPs have been characterized by using FT-IR, Ultraviolet–visible spectroscopic techniques, SEM, TEM& XRD techniques. The structure and size of the Copper oxide nanocrystals have been obtained from XRD analysis. The sizesof the Copper oxide nanocrystals have been found25.40 nm and 32.7 nm. XRD analysis results end-centered monoclinic structure of copper oxide nanocrystals. The sizes of CuONPs results from SEM have been 37.78 nm and 17.8 nm. The anticancer activity of CuONPs was tested against MM2 cell lines and showed significant activity. The results revealed that about 50 % of the cell viability (IC 50 ) was found to be at a 25 μg/mL concentration of CuONPs. Similarly, for CuONPs using Polianthes tuberosa , 50 % of the cell viability (IC 50 ) was found to be at a 20 μg/mL concentration of CuONPs. In the future, it could be used for further anticancer studies and drug discovery processes.

Screening of four accelerated synthesized techniques in green fabrication of ZnO nanoparticles using Willow leaf extract

Abstract Using hydro-alcoholic extract of Willow leaf, zinc oxide nanoparticles (ZnO NPs) were synthesized via four accelerated different heating methods namely, Bain-Marie heating (40 °C for 2 h), Conventional heating with stirrer (80 °C for 2 h), hydrothermal autoclave (1.5 atm and 121 °C for 15 min) and microwave irradiation (800 W and 160 °C for 3 min). Calcination process was finally completed on the obtained colloidal solutions in a furnace (350 °C for 2 h). The characteristics of the resulted ZnO NPs including particle size, grain size, crystallinity, specific surface area, morphology, photocatalytic, antioxidant bactericidal activities were estimated using X-ray diffractometry, scanning electron microscopy and Ultraviolet-visible spectroscopy techniques. Attained results indicated that among four different utilized synthetic methods, the fabricated ZnO NPs via Bain-Marie heating, had desired physico-chemical characteristics and bactericidal effect including small particle size (70 nm), high specific area (284 m2/gr), antioxidant activity (28.5%), photocatalytic activity (degradation of 50% of Methylene Blue), and bactericidal effects against Escherichia coli (clear zone diameter of 1.4 ± 0.1 cm) and Staphylococcus aureus (1.3 ± 0.1 cm).

Nickel Doped Zinc Oxide Thin Films for Visible Blind Ultraviolet Photodetection Applications

The current research aims to investigate the effect of nickel doping on the structural and opto-electrical characteristics of zinc oxide thin films. Sol-gel spin coating technique has been utilized to deposit Zn1-xNixO (x = 0, 0.005, 0.010, and 0.015) films on glass substrates. X-ray diffraction (XRD) analysis confirms the formation of crystalline zinc oxide thin films with hexagonal wurtzite structure. Williamson-Hall analysis has been performed to study the individual contribution of lattice strain and crystallite size to the peak broadening in the XRD pattern. Scanning electron microscopy (SEM), Photoluminescence spectroscopy, and UV–visible spectroscopic techniques have been used to examine the surface morphology and optical properties of the deposited films. Transient photocurrent measurements have been performed on all the films under the exposure of ultraviolet (UV) light of wavelengths 365 and 254 nm with on/off cycle of 100 s, and various device key parameters such as sensitivity, responsivity, and quantum efficiency, etc have been determined. Sensitivities of the fabricated photodetectors (PDs) are found to be 5463%, 3809%, 3100%, and 831% for pristine ZnO, Zn0.995Ni0.005O, Zn0.99Ni0.01O, and Zn0.985Ni0.015O, respectively. The UV photodetection mechanism, which is based on the interaction between chemisorbed oxygen on the surface of ZnO and photo-generated holes, has been thoroughly discussed.

Controlled morphological synthesis of temperature-dependent CuO nanostructures and their effect on photocatalytic performance

With the development of the times, more and more pollutants such as dyes produced by industry have inevitably caused harm to human health. Dyes are complex and stable in structure, and traditional methods of physically and chemically processing dyes have been proven to be inefficient. The heterogeneous photocatalytic technology has been widely regarded as one of the most promising processes for the treatment of harmful organic wastewater. In this paper, copper oxide (CuO) nanomaterials were synthesized via a hydrothermal method and it was found that the stirring temperature can regulate its morphology and structure, which in turn affects the optical, electrical and catalytic properties of the final product. By controlling the stirring temperature, CuO nanomaterials in the range of ∼30–500 nm were obtained. The as-prepared composites were characterized using x-ray diffraction, transmission electron microscope, scanning electron microscopy, and ultraviolet-visible spectroscopy techniques, among others. After a possible mechanism was proposed according to the above data, the photocatalytic performance of the CuO nanomaterials was evaluated by measuring the decomposition rate of rhodamine B (RhB) solutions. The results indicated that the CuO obtained at 100 °C exhibited excellent photocatalytic activity in comparison to other samples, with around 93% degradation of the RhB solution after 80 min. Finally, the recycling performance of the CuO nanomaterials was also tested and found to be extremely stable, with a high degradation level of 78% maintained after five cycles. In conclusion, the CuO nanomaterials are efficient catalysts for the complete degradation of RhB.

Synthesis, characterization, spectroscopic properties and computational studies of some new azo dyes derived from 5-chloro-8-hydroxy quinoline

Purpose The purpose of this study, 3-aminopyridine, 8-aminoquinoline and some new synthesized 2-aminobenzothiazoles were diazotized with nitrosyl sulfuric acid and subsequently coupled with 5-chloro-8-hydroxy quinoline to synthesize the corresponding heteroarylazo dyes 6–13. Design/methodology/approach The structures of dyes were characterized by mass, Fourier transform infra red, 1H proton nuclear magnetic resonance and ultra violet-visible spectroscopic techniques. Absorption spectra of the dyes were measured in acetic acid, ethanol, chloroform, acetonitrile, dimethyl formamide and dimethyl sulfoxide and correlated with the nature of the solvents and substituents. The effects of varying pH on the absorption wavelengths of the azo dyes were also studied. In addition, the acidity constants (pKa) of the dyes were determined using the spectrophotometric method in an ethanol-water mixture (80:20, v/v) at 20–23°C. Besides, density functional theory (DFT) calculations were carried out to compare the energies of proposed azo and hydrazone tautomers of the dyes. Findings The results showed that the withdrawing chloro groups on the diazo moiety have significant influence (red shift) on the electron absorption spectra of these dyes. In addition, introducing electron withdrawing chloro groups into the benzothiazoles moiety increased the acidic character of dyes. Originality/value The synthesized 7-hetroarylazo-5-chloro-8-hydroxy quinoline dyes are new members in the 8-hydroxyquinoline azo dyes family, where very few details regarding the synthesis of such dyes are reported before in the literature. They are unique in terms of synthesis, spectral properties and DFT calculations.

Analysis of growth mechanisms and microstructure evolution of Pb+2 minor concentrations by electrodeposition technique

In this study, the electrodeposition technique has been used to deposit low concentrations of highly toxic lead (Pb) cations into a solution of nitrate at a constant potential of − 1 V on fluorine-doped tin oxide electrodes (FTO). Monitoring of the reaction was conducted with the assistance of a computerized potentiostat/galvanostat setup, in cyclic voltammetry and in situ chronoamperometry modemodes. X-ray diffraction, scanning electron microscopy, energy-dispersive X-Ray, and ultraviolet–visible spectroscopy techniques were used to examine the crystal structure, morphology, and optical properties of the lead deposits, respectively. Pb regular micro-hexagons have been identified; their size and density were significantly influenced by the cationic precursor’s concentration. The correlation between the morphological and crystallographical structures of the electrodeposits was discussed. Based on chronoamperometric measurements, a mechanism for the growth of Pb deposits on FTO substrate has been proposed. Based on the reported results, electrodeposition processes of low heavy metals concentrations in contaminated water could be optimized using the eco-friendly electrodeposition technique.

Structural and optical parameters of sol-gel derived Barium Strontium Titanate (BST) thin film

Barium Strontium Titanate thin film was fabricated successfully on a corning glass substrate via sol-gel process technique. The as-prepared film was found to be amorphous, which crystallizes after annealing at different temperatures (500 °C, 550 °C). The influence of annealing temperature on the structural and optical properties of the fabricated thin films was analyzed. The XRD data reveals that the samples have a cubic structure with preferred orientation along (110) plane. Ultraviolet–Visible spectroscopy technique was used to determine various optical parameters such as transmittance, extinction coefficient (k), optical band gap, refractive index (n), and Urbach energy of the fabricated thin films. The optical bandgap of the crystalline sample decreased from 3.52 eV to 3.41 eV with the increase in annealing temperature. Optical transmittance spectra in the wavelength range 300 ∼ 1100 nm show good optical transparency of the BST thin film. The variation of the extinction coefficient and refractive index as a function of frequency has been discussed and reported. Optical parameters of the prepared thin film suggest its potential application in optoelectronic devices.

Molecular structure and quantum chemical evaluation of antiviral drug Atropine using vibrational spectroscopy and in-silico studies

Atropine was characterized by FT-IR, FT-Raman and Ultraviolet–Visible spectroscopic techniques. Optimization of molecular structure is accomplished with the support of density functional theory calculations. Vibrational spectral investigation exposes candid evidence for the influence of charge transfer on molecule activity. Experimental UV–Visible spectrum has been compared with the predicted electronic absorption spectrum obtained from TD-DFT estimations. For electronic absorption, along with IR and Raman spectra, high compactness is observed with the predicted and experimental results. Molecular docking of Atropine with target proteins admits its anticancer activity.

Effect of Vanadium Oxide on the Structure and Li-Ion Conductivity of Lithium Silicate Glasses

The commercially ubiquitous liquid electrolytes for lithium-ion batteries have several shortcomings in terms of safety. Therefore, development of solid electrolytes, especially those that are glass-based, has been gaining increasing interest in recent times. However, the fundamental understanding of the changes in the glass structure and the corresponding changes in the properties due to the addition of dopants is necessary for the development of glasses. Therefore, here, we report a study on the role of vanadium on the glass structure, ionic conduction, crystallization behavior, and other properties of lithium silicate-based glasses (23Li2O–2.64K2O–2.64Al2O3–71.72SiO2) as a solid electrolyte for high-temperature Li-ion battery applications. Furthermore, we proposed a mathematical model to describe/quantify the ion-conducting channels’ connectivity in glasses. The experimental glass structures were assessed using 29Si, 51V, 27Al nuclear magnetic resonance, Fourier transform infrared, and ultraviolet–visible spectroscopy techniques. The ionic conductivity was measured by impedance spectroscopy, and the crystallization behavior was studied by optical microscopy and X-ray diffraction. Furthermore, molecular dynamics simulations were also used to gain structural insights of the glasses. In the designed compositions, the addition of vanadium decreased the overall concentration of Li+ ions. However, the results revealed that the ionic conductivity improved with the addition of vanadium in spite of a decrease in the number of charge carriers. This suggests that vanadium makes the pathways easier for the conducting ions. Thus, we conclude that vanadium modifies the conduction channels to promote better hoping of the ions from one site to another.

Effect of preparation temperature on the structural, optical and electronic properties of co-doped ZnS nanostructures

In the present work, the effect of preparation temperature on the structural, optical and electronic properties of cobalt doped zinc sulfide (Zn0.95Co0.05S) nanostructures have been explored. Zn0.95Co0.05S nanostructures were synthesized at different preparation temperatures (300, 400 and 500 °C) using the thermolysis method. All samples resembled a single phase cubic zinc blende structure. Upon raising the preparation temperature, the lattice parameter decreases and the anisotropic nature of the crystallite size of the samples is changed into isotropic nature. Rietveld analysis discloses that cobalt (Co) could be incorporated substitutionally for zinc (Zn) ions with occupancies in good agreement with the value intended for preparation. The major characteristic vibration bands of zinc sulfide (ZnS) were determined using Fourier transforms infrared and slightly increased in the wavenumber upon raising the temperature. Ultraviolet–visible spectroscopy technique reveals an increase in the optical band gap upon increasing temperature from 300 to 400 °C, and then it reduces at 500 °C. Different defects in the different samples are concluded using the emission colors obtained from the photoluminescence technique. Density function theory calculation was applied to investigate the different electronic and optical parameters of ZnS and Co-doped ZnS with and without oxygen.

SYNTHESIS AND CHARACTERIZATION OF COBALT SUBSTITUTED W TYPE HEXAGONAL FERRITES

In this work W type hexagonal ferrites with chemical composition Sr1-xCrxCo2Fe16O27(x= 0.0, 0.02, 0.04, 0.06, 0.08, 0.1) were synthesized by sol gel auto combustion method. Annealing of the samples was done at 1200 C for 8 hours. Structural and optical properties and grain morphology of the synthesized samples were studies through X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Ultraviolet visible spectroscopy techniques and scanning electron microscope (SEM). XRD analysis confirmed that all samples exhibited hexagonal W-type single phase crystalline structure at temperature range of 1200oC with no impurity phase. The estimated grain size from SEM images is in the range of 76-139 nm that confirms nanocrystalline structure of samples with hexagonal structure. The FT-IR spectral analysis exhibited that absorption band occurred in ranging from 450 cm-1 to 650 cm-1 . Evidence of successful formation of hexaferrites was revealed by FTIR spectra of prepared samples. The existence of metal oxygen bond at octahedral site and tetrahedral site confirms that all fabricated samples exhibit W-type hexagonal ferrites. Optical characteristic of Sr1-xCrxCo2Fe16O27 analyzed by UV-Visible spectroscopy. The absorption spectra of synthesized nanoparticles of W-type recorded in range of wavelength 300 to 800 nm. This spectroscopy is significant in exploration of materials electronic properties. W-type hexagonal ferrites are suitable for high frequency application such as microwave devices.

Synthesis and Characterization of Aluminium and Cobalt substituted W type Hexagonal Ferrites

Our work utilized sol-gel auto combustion method for M-type ferrites synthesis with hexagonal orientation having chemical composition Ca (1-X) AlXCo2Fe16O22. Annealing of the samples was performed for 8 hours at 1200oC. Structural properties and grain morphology of the synthesized samples included X-ray diffraction (XRD), Fourier transforming infrared spectroscopy (FTIR), Ultraviolet visible spectroscopy techniques and scanning electron microscope (SEM). The XRD analysis verified that all samples exhibited single-phase crystalline hexagonal w-type structure at a temperature range of 1200oC without impurity level. The approximate grain size from SEM images is within the range of 76-139 nm, which confirms nanocrystal line structure of hexagonal samples. The spectral analysis of the FT-IR showed that the band of absorption ranged from 450 cm-1 to 650 cm-1. FTIR spectra of prepared samples disclosed proof of positive formation of hex ferrites. The presence of metal oxygen bonding at octahedral site and tetrahedral site indicates that all manufactured samples show hexagonal ferrites w-type hexagonal ferrites are ideal for application with high frequency applications, such as microwave systems.

Room temperature highly sensitive chlorine sensor based on reduced graphene oxide anchored with substituted copper phthalocyanine

The development of low cost, efficient and reversible chemiresistive sensors is one of the future challenges for the detection of harmful and toxic gases. In this direction, the effect of anchoring of hexadecafluorinated copper phthalocyanine (F16CuPc) molecules on to the reduced graphene oxide (rGO) sheets has been investigated for the first time, to develop a room-temperature chemiresistive sensor that can efficiently detect chlorine (Cl2) even down to few parts per billion (ppb) level. The rGO/F16CuPc hybrid materials characterized by X-ray photoelectron, Raman, Fourier transform infrared and ultraviolet-visible spectroscopy techniques indicated the presence of a strong synergetic interaction between the F16CuPc molecule and rGO sheet. Besides, scanning electron microscopic studies revealed that F16CuPc molecules assembled to form nano-flower type structures on rGO sheets. Under optimal conditions, the as-fabricated sensor exhibited improved response/recovery characteristics in comparison to its unsubstituted rGO/CuPc counterpart. The significant improvement in gas sensing characteristics has been independently verified by electrochemical impedance spectroscopy technique.