Zinc oxide (ZnO) nanoparticles (NPs) have been synthesized using Hibiscus subdariffa leaf extract. Temperature dependent synthesis and particle growth have been studied. Formation of NPs was confirmed by UV-visible (UV-VIS) spectroscopy, Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). Electron microscopy has been used to study the morphology and size distribution of the synthesized particles. The synthesized ZnO nanoparticles as potential anti-bacterial agents have been studied on Escherichia coli and Staphylococcus aureus. Another study has indicated that small sized ZnO NPs, stabilized by plant metabolites had better anti-diabetic effect on streptozotocin (STZ) induced diabetic mice than that of large sized ZnO particles. It has also been observed by enzyme linked immunosorbent assay (ELISA) and real time polymerase chain reaction (RT-PCR) that ZnO can induce the function of Th1, Th2 cells and expressions of insulin receptors and other genes of the pancreas associated with diabetes.

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Green synthesis of zinc oxide nanoparticles using Hibiscus subdariffa leaf extract: effect of temperature on synthesis, anti-bacterial activity and anti-diabetic activity

Recent research and progress of biodegradable zinc alloys and composites for biomedical applications: Biomechanical and biocorrosion perspectives.

Photoconductive Schottky diode based on Al/p-Si/SnS2/Ag for optical sensor applications

Zinc oxide (ZnO) nanoparticles (NPs) anchored to carbon nanofiber (CNF) hybrids were synthesized using a facile coprecipitation method. This report demonstrates an effective strategy to intrinsically improve the conductivity and supercapacitive performance of the hybrids by inducing oxygen vacancies. Oxygen deficiency-related defect analyses were performed qualitatively as well as quantitatively using Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. All of the analyses clearly indicate an increase in oxygen deficiencies in the hybrids with an increase in the vacuum-annealing temperature. The nonstoichiometric oxygen vacancy is mainly induced via the migration of the lattice oxygen into interstitial sites at elevated temperature (300 °C), followed by diffusion into the gaseous phase with further increase in the annealing temperature (600 °C) in an oxygen-deficient atmosphere. This induction of oxygen vacancy is corroborated by diffuse refl...

Oxygen Vacancy-Induced Structural, Optical, and Enhanced Supercapacitive Performance of Zinc Oxide Anchored Graphitic Carbon Nanofiber Hybrid Electrodes

A review of carbon quantum dots and their applications in wastewater treatment.

Highly oriented and transparent ZnO thin films have been fabricated on ultrasonically cleaned quartz substrates by the sol-gel technique. X-ray diffraction, UV-VIS, FTIR, photoluminescence and SEM are used to characterize ZnO thin films. X-ray diffraction study show that all the films prepared in this work have hexagonal wurtzite structure, with lattice constants a = b = 3.260 A, c = 5.214 A. The optical band gap energy of the thin films is found to be direct allowed transition ~3.24 eV. The FTIR spectrum of the film has the characteristics ZnO absorption band at 482 cm −1 . The photoluminescence spectrum of the samples has an UV emission peak centred at 383 nm with broad band visible emission centred in the range of 500 - 600 nm.

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Optical and Structural Properties of ZnO Thin Films Fabricated by Sol-Gel Method

The electrical properties of poly[2-methoxy-5-(2′-ethyl hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) films were studied at different concentrations of acridine orange (AO) dye in the temperature range (293–416 K). MEH-PPV was dissolved in n-butyl acetate and was doped with different concentrations of AO dye solution. The MEH-PPV films were prepared by spin-coating technique with the speed of 1000 rpm. For conductivity measurements, Cu electrode contacts in planar configuration were made on the top surface of the film by RF sputtering. The DC conductivity and steady-state photoconductivity measurements were performed on these spin-coated thin films. It was observed that the doping of AO dye reduces the electrical resistivity as well as activation energies and enhances DC conductivity and photoconductivity. An increase in DC conductivity can be explained in terms of hopping conduction in the wide range of localised states. Photoconductivity measurements are useful in determining the nature of optical charge generation and transport in conjugated polymers. The value of T0 (measurement of disorderness) is in good agreement with the XRD spectra, which depicts the amorphous nature of the pure MEH-PPV film. Photocurrent dependence on incident radiation has also been observed which follows the power law (Iph∝Fγ). This dependence shows that the recombination with in the localised state is predominant.

Electrical transport properties of poly[2-methoxy-5-(2′-ethyl hexyloxy)-1,4-phenylene vinylene] thin films doped with acridine orange dye

Hydrothermal treatment of red lentils for the synthesis of fluorescent carbon quantum dots and its application for sensing Fe3

On the crystallization kinetics of amorphous Se80In20−xPbx

In this work, a facile one step approach has been applied for the synthesis of nitrogen and sulphur co-doped water soluble carbon quantum dots (NS-CQDs) through hydrothermal treatment of L-Lysine and thiourea. The obtained NS-CQDs have a high quantum yield (QY) of 53.19 % and emit strong blue fluorescence under UV light excitation of wavelength 365 nm. The morphology of NS-CQDs is spherical in shape and their sizes are distributed in the range 5–8 nm with average diameter 6.86 nm. Moreover the NS-CQDs show excitation dependent emission behavior due to quantum confinement effect. Additionally, NS-CQDs serve as a fluorescent probe for the selective and sensitive detection of picric acid (PA) in aqueous solution. A good linear response to PA in the concentration range 1–10 μM with a detection limit 0.24 μM has been obtained. The high selectivity of PA by NS-CQDs is suggested to arise from fluorescence resonance energy transfer (FRET) mechanism. Finally these NS-CQDs fluorescent probes have been examined in real water sample by measuring the concentration of PA in tap water.

A facile one step hydrothermal synthesis of carbon quantum dots for label -free fluorescence sensing approach to detect picric acid in aqueous solution

Mohammad Zulfequar

Papers

Optical and Structural Properties of ZnO Thin Films Fabricated by Sol-Gel Method

Electrical transport properties of poly[2-methoxy-5-(2′-ethyl hexyloxy)-1,4-phenylene vinylene] thin films doped with acridine orange dye

Hydrothermal treatment of red lentils for the synthesis of fluorescent carbon quantum dots and its application for sensing Fe3

On the crystallization kinetics of amorphous Se80In20−xPbx

A facile one step hydrothermal synthesis of carbon quantum dots for label -free fluorescence sensing approach to detect picric acid in aqueous solution