Wet Chemical Reaction Method Research Articles

Corrosion behavior of pulse laser deposited 2D nanostructured coating prepared by self-made h-BN target in salinity environment

Hexagonal boron nitride (h-BN) target was prepared by two step wet chemical reaction method using a nontoxic starting materials (urea and boric acid). Optimized annealing parameters (1600 °C for 2 h) and N2 environment are applied for pertinent growth of boron nitride nano powder. A mechanical procedure was acquired to convert this powder into pallet (target) for further analysis. The prepared target (white pallet) was used to fabricate the corrosion resisting h-BN nano-sheet coating using pulse laser deposition technique. A thick h-BN coating was deposited on SS 304 and Si substrates. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) were employed to characterize the coating for structural and morphological purpose. X-ray photoelectron spectroscopy (XPS), Atomic force microscopy (AFM), and energy-dispersive X-ray spectroscopy (EDXA) were employed to characterize the coating for surface properties and chemical composition purpose. However, Contact angle and electrochemical work station were employed for wetting and corrosion analysis tests. We find that pulsed laser deposition (PLD) grown h-BN coating shows the non-wetting (134.2°) and reduce corrosion rate by one order of magnitude compared to bare SS. On the basis of these results, the h-BN nano-sheet coating may be a promising candidate for corrosion resist application in (3.5% NaCl solution) salinity environment.

Investigation of Synthesis of Sodium Aminodiborane in One Step and Its Reaction Kinetics

In this study, sodium aminodiborane (NaNH2(BH3)2) synthesis was carried out in a constant volume batch reactor with a single feed at various temperatures and inlet molar ratios. It was synthesized, ammonia borane and sodium hydride as precursors, by a wet chemical reaction method using tetrahydrofuran which is a solvent under atmospheric pressure. These experiments were carried out at varied temperature ranges from 0 °C to 24 °C, and varied inlet molar ratios (AB/NaH) from 0.75 to 1.25. Sodium amidoborane is synthesized when the experiment is carried out in a stoichiometric ratio, but sodium aminodiborane is synthesized when the mole of ammonia borane is higher than the mole of sodium hydride. In order to characterize the products, FTIR, XRD, GC-MS/MS, and quantitative analysis techniques were utilized. In addition, sodium aminodiborane’s synthesis reaction kinetic was determined. r apparent = 0.8594 e ^ (- 4366 / RT) C AB ^ (0.8) C NaH ^ (0.2). The apparent activation energy, Ea, and frequency constant, k0, were calculated about 4366 J/mol and 0.8594 h-1, respectively

Controllable synthesis of tunable aspect ratios novel h-BN nanorods with an enhanced wetting performance for water repellent applications

One dimensional (1-D) nanostructured layer with tunable aspect ratio holds the prodigious potential for achieving smart surfaces with controlled wettability. Herein, a simple and cost-effective technique was employed to develop the high quality and novel hexagonal boron nitride (h-BN) nanorods. These h-BN nanorods (BNNRs) with tunable aspect ratio contained oriented aligned nanoparticles along the [0001] direction were prepared by wet chemical reaction method using non-toxic precursor (melamine, urea and boric acid). Controlled chemical reactions in applied atmosphere (Ar 90% + NH3 10%) play an important role to transform the morphological growth and tune the aspect ratio (AR) of h-BN nanorods by simply varying the annealing temperature (1100–1300 °C). The correlation between structural, morphological and wetting properties of prepared materials were also investigated in detail. The behavior of wettability was also analyzed in term of water contact angle and surface free energy using two complex models, Wu and Owens & Wendt. Overall, the effect of annealing temperature and atmosphere were accountable to trigger the growth (aspect ratio from ~2.5 to ~5.2) and wetting behavior from hydrophobic to ~ super hydrophobic (contact angle from 127° to 145°.). Produced at 1300 °C, the highly oriented h-BN nanorods with large aspect ratio (AR) ~5.2 and excellent wettability (hydrophobicity ~145°) may be a promising candidate for water repellent applications.

One-shot wet chemical synthesis and physical properties of pyrochlore iridates A2Ir2O7, (A = Sm, Gd, Dy and Er)

Iridates of the pyrochlore A2Ir2O7 family are interesting materials whose low-temperature properties depend sensitively on the A/Ir ratio. Due to specific difficulties, namely: (i) the volatile nature of IrO2 above 1323 K, and (ii) slow reaction kinetics between IrO2 and A2O3 below 1323 K (where A is a members of the lanthanide series), it is challenging to prepare phase pure and stoichiometric A2Ir2O7 samples using the conventional solid state reaction (SSR) method in a reasonably short time. To overcome these limitations, we synthesized A2Ir2O7 with A = Sm, Gd, Dy, and Er using a wet chemical reaction (WCR) method in a single sintering step at T = 1273 K (a temperature well below the sublimation point of IrO2) for 12 h, and compared their electrical resistivity, magnetic susceptibility and specific heat with the SSR samples. We show that WCR samples exhibit metal-to-insulator & all-in all-out transitions in agreement with previous reports. The high density, low-sintering temperature, lack of IrO2 losses, and shorter preparation time are some of the attractive features of WCR method. This should be useful in exploring the true ground state properties of these materials in future.

Air-stable and highly luminescent bismuth complex nanoparticles

We report, for the first time, the preparation of air-stable, solution-processed, luminescent Bi complex nanoparticles (NPs) through a one-pot wet chemical reaction method.

Structural, morphological and optical properties of MgO nanoparticles for antibacterial applications

Magnesium oxide (MgO) nanoparticles have been synthesized by wet chemical reaction method. The structural, optical and morphologies of MgO nanoparticles have been characterized by X-ray diffraction (XRD), UV–vis Spectrophotometry, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The synthesized nanoparticles were well-dispersed spherical nanoparticles with the average size of 16nm. The SEM and TEM reveal the formation of almost spherical shaped MgO nanoparticles. XRD shows the face cubic centred structure of the MgO nanoparticles. The observed antibacterial properties, suggest the possible utilization of prepared nanoparticles in water purification.

A facile synthesis of malic acid capped ZnSe transparent nanopellets and its optical properties

ZnSe transparent nanopellets have been synthesized by a simple wet chemical reaction method using malic acid as a surface capping agent. The structure, morphology and chemical compositions of the as synthesized samples were investigated by X-ray diffractometer, transmission electron microscopy and energy dispersive X-ray analysis. Ultraviolet visible absorption spectrum confirms that the absorption edge is located at 352nm which is blueshifted when compared to the value of bulk ZnSe. The photoluminescence spectrum shows that the emission peak is located at 428nm which corresponds to near band edge emission. The nanopellets have an average diameter of about 150nm and the length about 400nm. The possible growth mechanism is also addressed.

Tailoring of Morphology and Optical Properties of Bishydrazone-Capped ZnSe Nanorods

Hydrazone derivatives containing heterocyclic moieties have interesting ligational features. Various heterocyclic base ligands have been gradually used to synthesize nanomaterials; however, adapting task-specific ligand systems to guide the synthesis path towards desirable nanostructures and morphologies is rare. In this article, bishydrazone was used as a ligand to purposely modify the morphological structure of the zinc selenide nanostructures via wet chemical reaction method at room temperature. The as-prepared ZnSe nanorods are relatively uniform with an average diameter of ~100 nm at the core and top diameter of 8–10 nm. UV-Vis spectrum of the products displayed absorption maxima at 390 nm. Therefore, the obtained ZnSe nanorods may have promising applications in blue emitters, catalysts, and gas sensors. The presence of bishydrazone in the ZnSe nanorods is confirmed by the Fourier transform infrared spectrum. It would be expected that bishydrazone could be used to prepare other nanoscale metal selenides with special morphologies and improved properties on a large scale.

A Simple Method for Large-Scale Synthesis of Nano-Sized Zinc Sulfide

nanosized zinc sulfide (ZnS) is a special property semiconductor material widely used in many applications such as catalyst, light emitting diode, transistor, gas sensors, biosensors, UV-light sensors, and photovoltaic cell. The wet chemical method is a simple and low-cost method to prepare nanosized zinc sulfide. However, the wet chemical reaction using sodium sulfide without surfactant or template has rarely been reported. In the present work nanosized zinc sulfide particles were synthesized by simple wet chemical reaction method at room temperature and without any surfactant. The influence of sulfur source, sodium sulfide and potassium sulfide used as the reactant were investigated. The samples were characterized by scanning electron microscopy coupling with energy-dispersive X-ray spectroscopy (FESEM-EDX), and transmission electron microscopy (TEM). The results show that the nanoparticles of zinc sulfide were obtained from sodium sulfide and potassium sulfide with particles sizes are in the range of 10 to 50 nm and 25 to 50 nm respectively. In addition, from FESEM microphotograph the primary ZnS particles size of around 5 nm and 25 nm were obtained by 10% salt (sodium chloride, potassium chloride, sodium acetate) addition with sodium sulfide and potassium sulfide reactant respectively.

Optical properties of CaAl(SO4)2Br:RE (RE = Dy, Eu, Ce) novel phosphors.

A new phosphor CaAl(SO4)2Br doped with Dy, Ce and Eu is reported. Rare earth (Dy, Eu and Ce)-doped polycrystalline CaAl(SO4)2Br phosphors were prepared using a wet chemical reaction method and studied for X-ray diffraction and photoluminescence (PL) characteristics. Dy3+ emission in the CaAl(SO4)2Br lattice was observed at 484 and 574 nm in the blue and yellow regions of the spectrum, which are assigned to 4 F9/2→6H15/2 and 4 F9/2→6H13/2 transitions of the Dy3+ ion, respectively. While the PL emission spectra of CaAl(SO4)2Br:Ce phosphor showed Ce3+ emission at 347 nm due to 5d → 4f transition of the Ce3+ ion. In a CaAl(SO4)2Br:Eu lattice, Eu3+ emissions were observed at 593 and 617 nm, coming from the 5D0 → 7 F1 and 5D0 → 7 F2 electron transitions, respectively. The PL study showed that the intensity of electric dipole transition at 617 nm dominates over that of magnetic dipole transition at 590 nm. The maximum PL intensity was obtained for a 1mol% concentration of Eu3+ in CaAl(SO4)2Br host lattice. The results showed that the materialmay be a promising candidate as a blue-, yellow- and red-emitting phosphor.

Synthesis of gallic acid capped ZnSe transparent nanorods

Zinc selenide (ZnSe) transparent nanorods have been synthesized using gallic acid, a natural organic matter (NOM), as a capping agent using a simple wet chemical reaction method. The structure and morphology of ZnSe transparent nanorods have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The SEM and TEM images reveal the formation and the transparent nature of rod like nanostructures. The hexagonal wurtzite structure has been predicted from XRD results. Strong “blue shift” absorption and the enhanced luminescence property with respect to bulk have been observed from UV–vis spectrophotometry and photoluminescence spectrophotometry.

수용액에서 합성한 ZnO 나노구조체의 형상

ZnO nanostructures with various shapes were synthesized under ambient pressure condition by a wet chemical reaction method. Nanorods of ZnO with hexagonal cross-section and their aggregates with radiate shape were synthesized. Precursor concentration affected considerably the shape evolution of ZnO nanorods. Low precursor concentration was proved to be more preferable to the growth of ZnO nanorods, which is attributed to the intrinsic characteristics of chemical reaction in the synthesis of ZnO from zinc compounds.

Mössbauer spectroscopic and x-ray diffraction studies of Fe/SiO2 nanocomposite soft magnetic materials

Nanocomposite high resistive soft magnetic materials Fe/SiO2 (Fe volume fraction 50%) have been synthesized using a wet chemical reaction method. A series of metal-ceramic Fe/SiO2 nanocomposite powder samples were obtained by annealing the precursor at temperatures from 400 to 900 °C in the presence of a reducing agent. The compositions of the precursor and the successive heat-treated samples have been investigated by Fe57 Mössbauer spectroscopy and x-ray diffraction, which revealed that the annealing process reduces nanosize granular ferrihydrite to α-Fe, and indicated that 800 °C is the optimum annealing temperature.