Synthesis of ZnO nanoflowers by solution plasma

Abstract

We synthesized ZnO nanoflowers using a solution plasma. We examined the effects of the applied voltage and the concentration of the electrolyte on the morphology of the products. In the experiments, the zinc wire (cathode) was immersed in an electrolysis solution of K 2 CO 3 (concentration: 0.01 to 5.00 M) and was electrically melted by a glow discharge at different voltages ranging from 42 to 200 V. The results revealed that the products were nanoflowers having many nanorods (size: <100 nm). The ZnO nanoflowers had a wurtzite structure with the [0001] orientation in the growth direction. The product morphology changed with a change in the concentration of the electrolyte, C, and the applied voltage, V; that is, nanoflowers were generated under the limited conditions of (C, V) = (1.0 M, 66 V), (0.5 M, 80 V), and (0.1 M, 105 V).

Synthesis of stainless steel nanoballs via submerged glow-discharge plasma and its photocatalytic performance in methylene blue decomposition

“…This is shown in the case of TiO 2 and SUS nanoballs, where higher glow-discharge voltage produced small-sized nanoballs. For TiO 2 , the maximum voltage that can be applied was 150 V, and for SUS 160 V. In the case of ZnO, voltages between 100 and 135 V produced flower-like nanoparticles, whereas the optimal voltage for spherical nanoball production was 95 V. [2] However, there is a limit to the maximum voltage than can be applied; once this limit is exceeded, arc-discharge plasma appears and melts the electrode immediately. Other than voltage control, the nanoballs can be separated according to size by using different-sized filters.…”

“…Then they solidified into spherical nanoballs because of the surface tension and quenching effect of the electrolyte. [1,2,8] Nanoballs have good potential as photocatalytic materials because of their very small size and therefore high reactivity. Titanium oxide (TiO 2 ) and zinc oxide (ZnO) are wellknown photocatalytic/photoelectric materials.…”

“…Titanium oxide (TiO 2 ) and zinc oxide (ZnO) are wellknown photocatalytic/photoelectric materials. Under ultraviolet (UV) light irradiation, TiO 2 and ZnO photocatalysts were able to decompose organic pollutants such as textile dye effectively.…”

“…Furthermore, the concentration of the decomposition by-products can be measured using mass spectroscopy. [27À29] Stainless steel have been used as a photocatalytic material in its bulk form or as a nanosized substrate for photocatalysts such as TiO 2 . In its bulk form, the surface of stainless steel undergoes passivation and this layer was found to have photocatalytic ability when irradiated with UV light.…”

“…The nanoballs are characterised in terms of their physical characteristics (size, surface area, porosity, and surface morphology) and photocatalytic performance. While there has been many reports on the photocatalytic ability of TiO 2 [9À18] and ZnO, [20À25] there has been no report on the photocatalytic ability of SUS nanoballs. Furthermore, there are also no detailed reports concerning the synthesis of SUS nanoparticles as well.…”