Arc Discharge Method In Water Research Articles

Plasma Characteristics of Under-water Arc Discharge in Nanoparticle Fabrication

Synthetic nanoparticles are the process of making particles with a size of less than 100 nm and changing the properties of the material so that it can be improved to improve the usability of new products. One method that can be used is the arc discharge method in water, which is a synthetic method of nanoparticles, which is very simple because it does not require complicated equipment. This study uses graphene as an electrode, which is then immersed in water and mounted horizontally. Current and voltage monitoring is carried out during the arc discharge process using a Hall-based current sensor and the voltage is measured directly between the two electrodes. Variations in input current of 10A, 40A, 70A, and 100A affect the arc formed, current and voltage, and ionization energy. Monitoring with OES is also carried out to determine the shape of the plasma, and the wavelength when the arc occurs. The results obtained that the current has more effective and optimal results in synthesizing nanoparticles.

The effect of silver oxidation on the photocatalytic activity of Ag/ZnO hybrid plasmonic/metal-oxide nanostructures under visible light and in the dark

A new synergetic hybrid Ag/ZnO nanostructure was fabricated which is able to cause photocatalytic degradation (in high yields) of methylene blue under visible light as well as in the dark. In this nanostructure, ZnO was synthesized using the arc discharge method in water and was coupled with Ag via a chemical reduction method. X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy results confirmed the existence of defects in ZnO in the hybrid nanostructures; these defects act as electron traps and inhibit the recombination of electron-hole pairs. The absorption edge of the hybrid nanostructure shifts toward the visible region of the spectrum due to a combination of the Ag plasmonic effect and the defects in ZnO. Band-edge tuning causes effective visible light absorption and enhances the dye degradation efficiency of Ag/ZnO nanostructures. Silver oxidation in the hetero-structure changed the metal-semiconductor interface and suppressed the plasmonic enhancement. Nevertheless, the synthesized Ag/ZnO decomposed methylene blue in visible light, and the silver oxidation only affected the catalytic activity in the dark. This work provides insight into the design of a new and durable plasmonic-metal oxide nanocomposite with efficient dye degradation even without light illumination.

DC Arc discharge synthesized zirconia nanoparticles: shed light on arc current effects on size, crystal structure, optical properties and formation mechanism

In this study zirconia nanoparticles (NPs) were successfully synthesized via the direct current (DC) arc discharge method in water. Formation mechanism of NPs and the effect of arc current on morphological, structural and optical properties of NPs have been studied. The NPs were synthesized at four different currents in the 40–160 A range. SEM observations showed NPs are spherical in shape and their average size decrease from 40 to 22 nm by increasing the current from 40 to 160 A. XRD analysis revealed phase composition of NPs is a mixture of tetragonal and monoclinic for all the samples, and the phase fraction of NPs are arc current dependent in such a way that an increase in the current leads to an increase in the weight percent of the tetragonal phase. UV–vis spectroscopy indicated that the NPs exhibit optical characteristics of the wide energy band gap semiconductors with a significant amount of oxygen deficiency. Also the effect of the arc current on the energy band gap of NPs were investigated. An increase in the arc current decreases energy band gap of the NPs from 3.8 to 3.0 eV. Optical emission spectroscopy (OES) studies demonstrate formation of zirconia NPs at temperatures as high as 4953 K, thereby zirconium exited species react with some of oxygen containing species. Finally, Thermal radiation measurement is proposed as a nondestructive method to evaluate the active mechanisms in an arc discharge zone beside other methods such as OES.

Synthesis and Characterization of ZrO2 Nanoparticles by an Arc Discharge Method in Water

ZrO2 nanoparticles were produced by high current electrical arc discharge of zirconium electrodes in deionized (DI) water. A mixture of nanocrystalline ZrO2 monoclinic and tetragonal phase form based on X-ray diffraction (XRD) analysis. Dynamic light scattering (DLS) result indicates that the size of the particles increases by increasing the arc current. Absorption spectroscopy of the samples shows a red shift on absorption edge by increasing the arc current. Band gap of the produced ZrO2 nanoparticles at 10 A arc current corresponds to 5.4 eV, which decreases to 5 eV by increasing the arc current up to 20 A.

Photocatalytic activity of ZrO 2 nanoparticles prepared by electrical arc discharge method in water

ZrO 2 nanoparticles were synthesized through arc discharge of zirconium electrodes in deionized (DI) water. X-ray diffraction (XRD) analysis of the as prepared nanoparticles indicates formation a mixture of nanocrystalline ZrO 2 monoclinic and tetragonal phase structures. Transmission electron microscopy (TEM) images illustrate spherical ZrO 2 nanoparticles with 7–30 nm diameter range, which were formed during the discharge process with 10 A arc current. The average particle size was found to increase with the increasing arc current. X-ray photoelectron spectroscopy (XPS) analysis confirms formation of ZrO 2 at the surface of the nanoparticles. Surface area of the sample prepared at 10 A arc current, measured by BET analysis, was 44 m 2/g. Photodegradation of Rhodamine B (Rh. B) shows that the prepared samples at lower currents have a higher photocatalytic activity due to larger surface area and smaller particle size.

ZnO nanoparticles prepared by electrical arc discharge method in water

We produced ZnO nanoparticles by high current electrical arc discharge of zinc electrodes in deionized (DI) water. X-ray diffraction (XRD) analysis shows formation of crystalline ZnO phase with hexagonal structure and 14 nm single crystalline domain size. Dynamic light scattering (DLS) result indicates that at 5 A arc current, the size of the particles is about 100 nm and increases by increasing the arc current. Absorption spectroscopy of the samples obtained at different arc currents shows an absorption edge on 370 nm which has a red shift by increasing the arc current. Band gap of the produced ZnO nanoparticles at 5 A arc current corresponds to 3.8 eV which decreases to 3.3 eV by increasing the arc current up to 15 A. The photoluminescence (PL) spectrum of the sample showed a strong ultraviolet (UV) emission peak around 383 nm, corresponding to the ZnO nanoparticles.

Synthesis of Silicon Nanowires and Nanoparticles by Arc‐Discharge in Water.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Production of carbon nanoonions and nanotubes using an intermittent arc discharge in water

An intermittent arc discharge in water, which has several millisecond pulse width, was used to produce carbon nanoparticles. High-resolution TEM observation revealed that the aggregated nanoonions were obtained as the floating powders on the water surface and the rest products which contains multiwalled carbon nanotubes were found at the base of the water. Production efficiency of carbon soot which contains the carbon nanoonions and multiwalled nanotubes to consumption mass of carbon electrodes was also investigated. Production efficiency of carbon soot was increased about 3 times in comparison with a direct current (DC) arc discharge method in water.

Synthesis of silicon nanowires and nanoparticles by arc-discharge in water

Si nanowires of diameters 5-20 nm and nanoparticles of approximately 4 nm were synthesized by a simple arc-discharge method in water. The TEM analysis reveals that the growth direction of the observed Si nanowires is parallel to the {111} crystal planes.