Template free synthesis of PbS nanoparticles by sol-gel facile method under IR radiation at room temperature

Lead sulfide (PbS) nanoparticles have been synthesized from the precursor of lead nitrite tetrahydrate [Pb(NO3)2.4H2O] and thiourea [CH4 N2S] at room temperature by sol-gel method under the infrared (IR) irradiation. The synthesized PbS nanoparticles have been characterized by XRD, FE-SEM, UV-vis spectrophotometer, and FTIR. The dominant peak (200) in XRD pattern, microstructure and the absorption of PbS have been confirmed the formation of nanoparticles. The crystallite size of PbS nanoparticle has been observed to be 13 nm. The lattice constant

Effect of growth temperature and RF power on structural and optical properties of sputtered deposited PbS thin films

Lead sulphide (PbS) nanocrystalline thin films have been grown from sputtering with the variation of growth temperature and RF-Power. The intensity of single dominant peak (200) in XRD-pattern increases by increasing the growth temperature from 175 oC to 200 oC and RF power from 80 W to 100 W, respectively. The crystallite size and the strain of as-deposited PbS thin films have been calculated from XRD-peak profile analysis. Microscopic surface and cross-section images show the improvement in thin films growth in terms of alignment of grains and thickness. The band gap of PbS thin films has been determined from UV-Vis absorption spectra, where the band gap decreases from 1.98 eV to 1.72 eV as the growth temperature and power increased from 175 °C and 80 W to 200 °C and 100 W

Hydrogen induced resistance and optical transmittance of pulsed laser deposited Pd/Mg thin films

The hydrogen detection is an important issue for the societal acceptance of H2 as energy carrier. In present research work, we have investigated hydrogen sensing and optical properties of Pd/Mg thin films on glass substrate deposited by pulsed laser (PL). As-deposited thin films have been exposed (hydrogenation) to H2 gas (2 bar) at room temperature in a hydrogenation unit. Hydrogenated and dehydrogenated (at different temperatures) samples have been characterized using X-ray diffractometer (XRD), field-emission scanning electron microscopy (FE-SEM), UV-Vis-NIR spectrophotometer, atomic force microscopy (AFM). XRD results confirm the formation of hydride (MgH2) tetragonal phase upon hydrogenation of Pd/Mg films. Hydrogen induced resistance response of Pd/Mg films has been measured in-situ during hydrogenation/dehydrogenation process by using two- probe electrical method. The response time (sensitivity) of Pd/Mg films for hydrogen gas is ~ 60 s at room temperature. The study of optical transmittance of hydrogenated Pd/Mg films indicates their switchable mirror behavior

Gradation of Nanoparticle Size by Stokes' Law: A New Approach for Synthesis of CdS Nanoparticles

The synthesis technique and its allied process parameters have a specific effect on the nucleation, growth-dominated microstructure and properties of nanostructure materials. The properties of semiconductor nanoparticles strongly depend on its size, shape, composition, crystallinity and structure. Recently, semiconductor nanoparticles have been extensively investigated and gained much interest due to their unique properties and applications in diverse areas of science and technology. A new controlled technique for synthesis of CdS nanopartlicles by means of kinetic approach using well-known Stokes' law for free body falling in quiescent and viscous fluid has been employed. Nanoparticles of cadmium sulfide (CdS) have been synthesized by simple controlled chemical method using IR radiation heating without using any capping agent and stirring. The desired concentration of aqueous solutions of cadmium chloride (CdCl2.2H2O) and thioacetamide (CH3CSNH2) were reacted in a controlled manner by IR radiation heating at the reaction area (top layer of reactants solution) of solution results the formation of CdS nanoparticles following Stokes' law. The as-synthesized nanoparticles were characterized by XRD, optical spectroscopy and SEM with EDX analysis

Vacuum thermal deposition of crystalline, uniform and stoichiometric CdS thin films in ambient H2S atmosphere

Crystalline, uniform and stoichiometric thin films of CdS have been fabricated on soda lime glass (SLG) substrates using vacuum thermal deposition method in the presence of hydrogen sulphide (H2S) atmosphere. The consequence of ambient H2S on the growth, quality and structure-property relationship of vacuum deposited CdS thin films has been investigated. The deposited films have been characterized by XRD, SEM with EDX analysis, AFM, XPS and optical spectroscopy. The physical characterization of as-deposited CdS films reveals that the films deposited in controlled H2S ambient are more crystalline, highly uniform and stoichiometric in comparison to films deposited without H2S atmosphere

Quantitative analysis of Fe/Co co-doped ZnO by Rietveld method

Fe/Co co-doped Zinc oxide was prepared by using hydrothermal method. Refinement of recorded X-ray diffractograms was done by Rietveld method by using MAUD. It shows that all the samples have a hexagonal structure with space group P63mc and the average crystallite size of the samples lie between 49-79 nanometers. Presence of some secondary phases were also detected. Rietveld analysis data reveals that the density of the doped and co-doped ZnO is more than the pristine ZnO. The goodness of fit value ranges from 1.3875-1.7519. The unit cell volume decreases for the doped and co-doped ZnO as the value of lattice parameter decreases with doping and co-doping. Decrease in the interplaner spacing values may be because of the strain developed in the lattice due to doping and co-doping

Quantitative analysis of Fe/Co co-doped ZnO by Rietveld method

673-677Fe/Co co-doped Zinc oxide was prepared by using hydrothermal method. Refinement of recorded X-ray diffractograms was done by Rietveld method by using MAUD. It shows that all the samples have a hexagonal structure with space group P63mc and the average crystallite size of the samples lie between 49-79 nanometers. Presence of some secondary phases were also detected. Rietveld analysis data reveals that the density of the doped and co-doped ZnO is more than the pristine ZnO. The goodness of fit value ranges from 1.3875-1.7519. The unit cell volume decreases for the doped and co-doped ZnO as the value of lattice parameter decreases with doping and co-doping. Decrease in the interplaner spacing values may be because of the strain developed in the lattice due to doping and co-doping

Synthesis, characterization, and electrocatalytic ability of γ-Fe2O3 nanoparticles for sensing acetaminophen

Maghemite (γ-Fe2O3) nanoparticles have been synthesized using co-precipitation method followed by chemically induced transition process. As prepared nanoparticles have been analyzed by X-ray diffraction, Raman and FTIR spectroscopies which reveal the γ-Fe2O3 phase. These γ-Fe2O3 nanoparticles have been used to modify the glassy carbon electrode (GCE) to form nano γ-Fe2O3 modified GC electrode for electrochemical sensing of acetaminophen (C6H9NO2) using potential controlled cyclic voltammetric (CV) technique. The obtained modified electrode shows an excellent electrocatalytic ability to sense acetaminophen in 0.1 M KCl supporting electrolyte. In addition, a significant enhancement in anodic peak current has been observed using nano γ-Fe2O3 modified GC electrode than the bare electrode. The CV plots reveal that redox peaks have been linearly co-related to the acetaminophen concentration in the range of 0.031 mM to 1 mM with sensitivity ~30.78 µA/mM

Optimization of structural and optical properties of sputter deposited TiO2 thin films by controlling deposition parameters

735-739Titanium oxide (TiO2) thin films have been deposited onto highly cleaned soda lime glass substrates by DC magnetron reactive sputtering system. The Ti target with purity 99.99% is sputtered by argon gas in the sputtering chamber. Oxygen gas with purity 99.99% is introduced during the deposition process into the sputtering chamber as reactive gas for the synthesis of titanium oxide. Structural and optical properties of TiO2 thin films have been characterized by X-ray diffraction (XRD), Raman spectroscopy and UV-Vis. spectroscopy. The effect of substrate temperature and sputtering power on the optical properties of TiO2 thin films has been studied. The XRD and Raman spectroscopy of as-deposited films are used to study the structural properties of TiO2 as a function of substrate temperature and sputtered power. The structural studies show the crystalline nature of TiO2 thin films. The narrowing of energy band gap of sputtered deposited TiO2thin films was studied using UV-Vis. spectroscopy

Effect of CNT on the growth and agglomeration of TiO2 nanoparticles

825-831Titanium dioxide nanoparticles (TiO2-NPs) are agglomerated by inclusion of CNTs during the nucleation and growth process using the hydrothermal method at 160 ⁰C. The content of C-atoms was determined from EDAX-spectra and line scan. The XRD peak of TiO2 indicated the rutile phase R(210), while CNT- TiO2 showed the anatase phase A(004). Williamson-Hall (W-H) models showed the linear fitted negative slope, indicated the presence of compressive strain in TiO2 and CNT- TiO2 crystal lattice. Agglomeration of TiO2 nanoparticles was confirmed from the surface morphology and elemental analysis. The FTIR spectra showed the interfacial interaction between CNTs and TiO2 with vibrational frequency of Ti-O-C bonds at 1065 cm-1