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This research studies the effects of volume ratios on the properties of GO/(ZnxNi1−x)O ternary composite prepared by a sol–gel technique. The ratios were produced by keeping the volume of graphene oxide (GO) constant whilst varying the volumes of zinc oxide, ZnO and nickel oxide, NiO to produce GO/ZnO0.2NiO0.8, GO/ZnO0.5NiO0.5, and GO/ZnO0.8NiO0.2 nanocomposites. The structural, morphological, elemental, optical, gas sensing, and photocatalytic properties of the synthesized nanocomposites have been investigated. EDX results confirmed the presence of graphene oxide, nickel oxide, and zinc oxide in the composites. The bandgap energy values exhibited a reduction as compared to the constituent compounds which range from 3.1 to 3.4 eV. Functional groups belonging to carbon, oxygen, nickel, zinc were obtained. The conductivity and activation energy of the ternary composites was also determined. The gas sensing properties were tested for NH3, H2S, and Cl2 at 100 ppm and 10 V; with the highest sensitivity recorded for H2S. The synthesized ternary composites were highly effective in degradation of dye with the efficiencies of 87.3%, 86.7%, and 88.0% respectively, obtained at 0.022 per minute, 0.020 per minute, 0.024 per minute for pseudo-first order rate constant. Results from the characterization show potential application of the composites in gas sensing and photocatalytic devices. [ABSTRACT FROM AUTHOR]

MoO3 thin films have been prepared by a simple spray pyrolysis technique at substrate temperature 250°C. The structure and morphology of thin films are characterized by X-ray powder diffraction (XRD), scanning electron microscopy and UV-vis spectroscopy. The gas sensing properties of MoO3 thin film is studied at gas concentration 400 ppm and working temperature of 100-400 °C. It was found that the sensitivity depended on the working temperatures and also H2S gas concentration. The results show that the MoO3 thin film can be used to fabricate high performance H2S gas sensors. [ABSTRACT FROM AUTHOR]

Strontium titanate (SrTiO3) nanopowder has been synthesized through a sol-gel-hydrothermal method. The X-ray diffraction studies of SrTiO3 nanopowder have shown that the as-prepared powder was single phase, crystalline, and has a cubic perovskite structure (ABO3) with a lattice constant a = 3.903 Å. The particle size calculated from FWHM was ∼22 nm. SrTiO3 nanopowder was examined using thermo gravimetric analysis; differential thermal analysis and UV-visible absorption spectroscopy. The transmission electron microscopic investigations have shown that the particle size of the as-prepared powder has a mean size of 34 nm. Then highly sensitive and selective sensors to H2S based on glass substrate were fabricated successfully by screen-printing technique. Sensitivity, selectivity, response time, and recovery time of the sensors were systematically investigated as a function of operating temperature, using H2S, CO, CO2, H2, Cl2, LPG, C2H2OH, O2, NH3 and NO2 as test gases. The sensitivity was found to lie below and around the ppm level for H2S gas at 150 °C. [ABSTRACT FROM AUTHOR]

Tin oxide thin films were deposited on alumina substrates at 350°C by spray pyrolysis technique. The films were studied after annealing them in air at different temperatures 550°C, 750°C and 950°C for 30 min. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical absorption spectroscopy technique. The grain size was observed to be increased, ranging from 40 to 56.1 nm, with the increase in annealing temperature. Absorbance spectra were taken to examine the optical properties. The band gap energy was observed to be decreased with the increase in annealing temperature. These films were tested to various gases at different operating temperature ranging from 50°C to 450°C. The Tin Oxide film showed maximum sensitivity to H2S gas. The H2S sensing property of the SnO2 films was investigated with different annealing temperatures of the films and at different concentrations of H2S gas. It was found that the annealing temperature of the film significantly affects the sensitivity of the SnO2 to the H2S gas. The maximum sensitivity was found in case of the film annealed at temperature 950°C at the operating temperature 100°C. The sensitivity was found to be increased by 24% in case of the film annealed at 950°C as compared to the sensitivity of the film annealed at 550°C. The observed response of the film was for gas concentration of 10 ppm for H2S with reasonable sensitivity. The quick response and fast recovery are the main features of this film. The effect of annealing temperature on the structural, microstructural, optical and gas sensing properties of the nanocrystalline tin oxide thin films were studied and discussed. [ABSTRACT FROM AUTHOR]

Inorganic photocatalytic materials exhibiting a highly efficient response to ultraviolet-visible light spectrum have become a subject of widespread global interest. Nanocomposite metal oxides, particularly Nickel Oxide (NiO) and Zinc Oxide (ZnO), have gained attention for their diverse applications in gas sensing and photocatalytic processes. In this work, ZnO-NiO (ZnO0.6NiO0.4 and ZnO0.4NiO0.6) binary nanocomposites were synthesized by hydrothermal technique. The binary nanocomposites were analyzed by UV-Visible spectrophotometer, X-ray diffraction (XRD), photoluminescence (PL), Fourier transform infrared spectrophotometer (FTIR), energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The XRD pattern revealed that the nanocomposites, the peaks of both ZnO and NiO are present indicating the presence of both crystal structures hexagonal wurtzite and cubic. The miller indices, crystallite size, microstrain and dislocation density were determined from the XRD plot. FESEM and TEM analyses showed the spherical morphology of the synthesized composites with an approximate size of 10nm. The detailed analysis of ZnO–NiO binary nanocomposite sensor characteristics in terms of sensitivity, selectivity, response and recovery time were carried out and the nanocomposites were found to be highly sensitive to CO2 100 ppm at 350∘C and Cl2 at 200∘C. The photocatalytic degradation outcome showed 52% degradation of methylene blue at 10 ppm and 90w/m2. These results suggest the potential utility of these binary nanocomposites in photocatalytic applications for the degradation of organic pollutants. [ABSTRACT FROM AUTHOR]

Electron tunneling induced photon emission in gallium doped (1%) zinc oxide was detected by scanning tunneling microscope in ambient condition. Simultaneously acquired topography and photon maps reveal interesting correlation. Photon maps depict few intense emission spots. Existence of a threshold tunneling current (6 nA) and applied bias (1.8 V), for detectable photon emission was observed. Further analysis of the results suggests Fowler-type photon emission which is ascribed to radiative electron-hole recombination. Localized photon emission spectroscopy exhibits prominent peaks at hν=2.96, 3.43, and 3.80 eV, which match well with the results obtained from photoluminescence studies. [ABSTRACT FROM AUTHOR]

Background: Ayurdvedic derived medicines are most promising and effective in the treatment of several cardiovascular diseases. Cocculus hirsutus (CH) has been reported for broad spectrum of activities like anticancer, antidiabetic, antioxidant, cardiotonic and hypotensive etc. OBJECTIVES: The present study aimed to find the cardio-protective effect of CH in experimental hypertension in rats., Materials and Methods: For acute renal hypertension, CH animals were pre-treated with CH-1 (250 mg/kg) and CH-2 (500 mg/kg) p. o. for 14 days. On the 15th day, hypertension was induced by renal occlusion and the mean arterial blood pressure (MABP) was recorded. For CAL pretreatment of CH-1 and CH-2 was given for 7 days on the 8th day animals were operated on for ligation. The MABP and the time of onset of ventricular tachycardia (VT), premature ventricular systole (PVS) were recorded. For induction of hypercholesterolemia, animals were fed with a high cholesterol diet (CD) with CH-1 and CH-2 for 21 days. The antioxidant potential of CH was done using the assay of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione peroxidase (GPx)., Results: CH treatment significantly decreases the MABP, the onset of VT and PVS. The histology show intact cardiac muscle with minimum necrosis and inflammation. CH treatment shows significant decrease in cholesterol, triglycerides, and glucose while HDL levels are significantly increased. The aortic section of CH-treated animals shows the intact layers of the artery, normal thickness and restoration of antioxidant enzymatic activity., Conclusion: The study shows significant cardio protective effect of CH in experimental animals., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

The current investigation was carried out to screen antiarthritic potential of Methyl Jasmonate (MJ) against lipopolysaccharide (LPS) induced arthritis. Cartilage damage was induced in experimental animals by intraplantar administration of LPS (1 mg/kg) and antiarthritic effect of MJ was screened in two doses of MJ-1 (20 mg/kg), MJ-2 (40 mg/kg) by intraperitoneally administration. Indomethacin (30 mg/kg p.o.) was used as standard drug. The severity of arthritis was evaluated by assessing arthritis score, secondary lesions, motility test, stair climbing ability, and dorsal flexion pain score method. The estimation of blood cytokine tumor necrosis factor- aplha (TNF-α),interleukine (IL-2 and IL-6) and thymus/spleen index was carried out to access the severity of inflammation. Estimation of hepaticenzymatic antioxidant activity superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx)and radiological examination was carried out on 28 th day. Results indicated that MJ showed significant reduction in severity of arthritis by decreasing arthritis score, secondary lesions where as significant increase in motility, climbing ability and flexion pain score was observed. Significant decreased in blood cytokine viz. TNF-α, IL-2, IL-6 andthymus/spleen index was observed in MJ treated animals in dose dependent manner. MJ treated animals showed significant increased and restoration of hepatic antioxidant enzymatic activityof SOD, CAT, GSH, GPx where asradiological examination indicates protective effect on joint structure as compared to LPS treated rats. These current studies conclude that MJ has protective role in arthritis., Competing Interests: The authors declare no conflict of interest., (© 2020 Published by Elsevier Ltd.)

Herein we describe synthesis of ZnO nanoparticles by using alkaline solution of ZnX2 (X = NO3, Cl) under ultrasound energy of 20 KHz. The reaction can be completed in about 1-2 hours. As prepared powders were analyzed by XRD measurement to find that the product is hexagonal phase pure ZnO. UV-Visible measurement of aq. solution showed absorption band at -365 nm and photoluminescence (PL) indicated multiple bands in visible region due to deep traps owing to high temperature sintering. The hydrophilicity can be imparted by use of a suitable polyelectrolyte. Freshly prepared samples showed good dispersion in aqueous and alcoholic medium. The thick films derived from the ZnO nano-particles showed excellent sensing for hydrogen sulphide gas.