International Nano Letters

Undoped nanocrystalline n-type ZnO thin film was deposited by chemical deposition technique on a thermally oxidized p-Si (~5 Ω cm resistivity and <100> orientation) substrate. Formation of stable zinc oxide thin film was confirmed by two-dimensional X-Ray Diffraction (XRD) and EDX analysis. The average crystallite size of the ZnO sample was evaluated as ~50 nm. The surface was characterized by Field Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM) that confirm the formation of nanocrystalline (grain size ~50 nm) ZnO thin film with surface roughness of ~100 nm. Good conversion of precursor into ZnO thin film in the chemical deposition method was evident by Fourier Transform Infrared Spectroscopy (FTIR). A small peak at 479 cm−1was observed in the FTIR spectrum confirming the formation of quartzite structure of the ZnO. The band gap (~3.44 eV) of the material was calculated from the optical absorption spectroscopy. To prepare Pd–Ag/n-ZnO Schottky junction, Pd–Ag contacts were taken by electron beam evaporation method. I–V characteristics of the junction were studied at different temperatures in inert and reducing ambient (N2 and N2 + CH4) with turn on voltage of around 0.2 V. The parameters like ideality factor (η), saturation current (I 0), series resistance (Rs), and barrier height (Φ BO) of the junction were calculated in the temperature range 50–200 °C in N2 as well as in 1 % CH4 + N2 ambient. It was observed that the ideality factor decreases in the temperature range 50–200 °C (η = 12.34 at 50 °C and η = 1.52 at 200 °C) in N2 ambient and η = 1.18 in N2 +CH4 ambient at 200 °C. Schottky Barrier Height (Φ BO) of the Pd–Ag/n-ZnO junction was found to increase with temperature. A close observation of Pd–Ag/n-ZnO junction in the presence of methane was performed to appreciate its application as methane sensor. The sensing mechanism was illustrated by a simplified energy band diagram.

Amorphous TiO2 obtained by adding TiCl4 to an alkaline medium crystallizes slowly and upon 3 years ageing transforms to nanosized anatase containing an admixture of brookite. The hydrothermal treatment of this sample in solutions of lithium hydroxide leads to anatase nanoleaves, and the more concentrated LiOH solution, the greater the nanoleaves and the smaller their specific surface area. The thermal treatment of nanoleaves leads to the bulk rutile, and the greater the specific surface area of anatase nanoleaves, the lower the anatase–rutile transition temperature. This is in line with conclusions based on the thermodynamic stability of nanosized anatase over the bulk rutile.

Microemulsions (MEs) could be considered as promising nutraceutical carriers for anthropoid consumption where their stability during storage is a real advantage. Considering powerful health benefits of lycopene and constant growing interest in green and safe extraction techniques, current study was aimed at ME extraction of lycopene from tomato industrial waste and monitoring of rheological behaviour, turbidity, refractive index, and colour characteristics of the developed ME during storage. Within 3 months, no significant changes were noted in the rheological behaviour and refractive indices of lycopene MEs in three different storage temperatures (5, 25, and 45 °C). However, at higher temperatures (25 and 45 °C), there was a progressive but slow increase in the turbidity, total colour difference, chroma, hue angle, and browning index values, whereas those stored at 5 °C presented no or fairly small changes over the study period. All in all, the best storage condition for the lycopene ME was concluded to be cold temperature under which it can stay almost unchanged for relatively long periods of time. Potential applications of lycopene MEs can be a wide range of beverages and foods which would result in their better colour and a well-documented health-promoting quality.

Highly crystalline Gd3+-doped cadmium oxide micro-structure was synthesized by calcining the obtained precursor of a sol–gel reaction. The reaction was carried out with cadmium nitrate (Cd(NO3)2·4H2O), gadolinium oxide, and ethylene glycol (C2H6O2) reactants without any additives at 80°C for 2 h. The resulting gel was calcined at 900°C with increasing temperature rate of 15°C/min for 12 h in a furnace. As a result of heating, the organic section of the gel was removed, and the Gd3+-doped cadmium oxide micro-structure was produced. The obtained compound from the sol–gel technique possesses a cubic crystalline structure at a micro scale. XRD study indicates that the obtained Gd3+-doped CdO has a cubic phase. Also, the SEM images showed that the resulting material is composed of particles with cluster structure. Also, FT-IR spectroscopy was employed to characterize the Gd3+-doped CdO micro-structures.

Development of improved methods for the synthesis of copper nanoparticles is of high priority for the advancement of material science and technology. Herein, starch-protected zero-valent copper (Cu) nanoparticles have been successfully synthesized by a novel facile route. The method is based on the chemical reduction in aqueous copper salt using ascorbic acid as reducing agent at low temperature (80 °C). X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy measurements were taken to investigate the size, structure and composition of synthesized Cu nanocrystals, respectively. Average crystallite size of Cu nanocrystals calculated from the major diffraction peaks using the Scherrer formula is about 28.73 nm. It is expected that the outcomes of the study take us a step closer toward designing rational strategies for the synthesis of nascent Cu nanoparticles without inert gas protection.

Three different flavonoids -hesperidin, naringin and diosmin (constituents of citrus plants) were used for the synthesis of silver nanoparticles (AgNPs). Aqueous solutions of pure flavonoids (0.2 mg mL−1) mixed with 1 mM AgNO3 solution were exposed to bright sunlight to prepare the nanoparticles. Characterization of the synthesized nanoparticles by UV–Visible spectrophotometer, X-ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy revealed that the synthesized silver nanoparticles were 10–80 nm in size and polydispersed in nature. Bactericidal effect against common pathogens and cytotoxicity of the synthesized silver nanoparticles was investigated on human promyelocytic leukemic (HL-60) cells. It is concluded that AgNPs synthesized using Naringin as reducing agent showed higher stability and better antibacterial and cytotoxic activities.

La2Ce2O7 nano-powders were synthesized via a hydrothermal reaction in a deionized water (S 1) and in a 2 M NaOH aqueous solution (S 2) at 180 °C for 48 h. La(NO3)3·H2O and (NH4)2Ce(NO3)6 were used in the stoichiometric 1:1 La:Ce molar ratio as raw materials. The obtained materials were crystallized in a cubic crystal structure with space group. The synthesized materials were characterized by powder X-ray diffraction technique and Fourier-transform infrared spectroscopy. To investigate the effect of the basic solution on the morphology of the obtained materials, the morphologies of the synthesized materials were studied by field emission scanning electron microscopy technique. The technique showed that the morphology of La2Ce2O7 samples changed from grain to rod-like structure in presence of the basic solution. Cell parameter refinements showed that these parameters were larger for S2 than those for S 1. Photoluminescence and ultraviolet visible spectra of the synthesized nanomaterials were also investigated.

This article was mistakenly published twice. For this reason this duplicate article has now been retracted. For citation purposes please cite the original: http://www.inljournal.com/?_action=articleInfo&article=22 Antimony-doped tin oxide (ATO) thin films were prepared by dip coating method. The effect of antimony doping on the structural, electrical, and optical properties of tin oxide thin films were investigated. Tin(II) chloride dehydrate (SnCl2·4H2O) and antimony(III) chloride (SbCl3) were used as a host and a dopant precursor, respectively. X-ray diffraction analysis showed that the non-doped SnO2 thin film had a preferred (211) orientation, but as the Sb doping concentration increased, a preferred (200) orientation was observed. The lowest resistivity (about 5.4 × 10−3 ΩΩ cm) was obtained for Sb-doped films at 2 at.%. Antimony doping led to an increase in the carrier concentration and a decrease in Hall mobility. The transmittance of ATO films was observed to increase to 96% at 2 at.% Sb doping, and then, it was decreased for a higher level of antimony doping.

A novel polymethyl methacrylate/boehmite nanocomposite with remarkably enhanced adsorption performance of Cu(II) was synthesized from $${\text{Al}}({\text{NO}}_{3} )_{3} \cdot 9{\text{H}}_{2} {\text{O}}$$ using a facile sol–gel method. The effects of boehmite content, contact time and morphology of hybrid (pH of synthesis) as the main parameters on removal efficiency and removal capability of hybrid on copper ions have been explored. Composites contained between 0.7 and 5wt% boehmite content and those with dissimilar morphology prepared with different pH values showed different adsorption behavior. Batch adsorption experiments show that the adsorption performance of the hybrids was enhanced with increased boehmite and contact time. The highest removal efficiency and adsorption capability were achieved when the hybrid was prepared at pH 8 with associated increased catalytic activity.

The need to monitor the presence of cyanide (CN−) in water is necessary to minimize the risks to aquatic ecosystems and human health. In this paper, a paper-based analytical device (PAD) was fabricated by immobilizing silver nanoparticles (AgNPs) on filter paper (FP) for the semi-quantitative colorimetric detection of CN− in water. The average diameter of the synthesized AgNPs was estimated to be around 26.23 ± 8.37 nm, with a characteristic optical absorption peak around 420 nm. Scanning electron microscopy and energy-dispersive X-ray spectroscopy results confirmed the successful immobilization of AgNPs on the filter paper via direct immersion technique. The potential of the fabricated FP-AgNPs PAD as a colorimetric sensor for CN− was evaluated using water samples contaminated with various ions and CN− concentration. Here, a color change from yellow to colorless was instantly observed as the FP-AgNPs PAD was exposed to water samples containing CN−. Interestingly, no color change was observed for samples exposed to other analytes suggesting the good selectivity of the FP-AgNPs PAD. Ultraviolet–Visible spectroscopy results and digital image analysis revealed that the fabricated sensor can detect CN− with concentration down to 1.0 ppm. The colorimetric response was also obtained for real water samples spiked with CN−. The results stipulated in this work offer baseline information that can be used in developing highly selective and sensitive digital sensing devices for affordable, accessible, and fast water contaminant monitoring and other related applications.