The Influence of Morphology on Photo-catalytic Activity and Optical Properties of Nanocrystalline ZnO Powder

Abstract

ZnO nano-particles were synthesized via an ammonical ammonium carbonate solution by precipitation method in presence of some additives such as urea, oleic and stearic acid. The morphology and crystallinity of the obtained zinc oxide particles depend critically on the type of additive which was used. Additives also affected the crystal orientation of precipitate nano-particles. SEM, XRD, BET and UV-visible were used to characterize morphology, microstructure, specific surface area and optical properties of the products. Photo-catalysis properties of the as-prepared ZnO powders were evaluated by degradation of methyl red (acid red) in aqueous solution exposed to UV-light. Results suggested a close relationship among the morphology, size and surface area on photo-catalysis and optical properties of the particles. The widest Eg value (3.56 eV), highest degradation and decolorization efficiency (99%) were obtained from a sample with the smallest grain size (largest surface area) which were used urea as an additive.

Tuneable luminescence properties of EDTA‐assisted ZnS:Mn nanocrystals from a yellow‐orange to a red emission band

“…Furthermore, the broadening of diffraction peaks confirmed that the obtained crystallites were of nano size. The crystallite size was calculated using Debye‐Scherer's equation (equation ) below . The average particle sizes, calculated by the full‐width at half‐maximum (FWHM)) of the border of the diffraction lines, were 3.5 nm for pure ZnS and 4.2 nm (0.05 M), 4.6 nm (0.1 M) and 5.1 nm (0.15 M) for Mn 2+ ‐doped ZnS nanocrystals, respectively.…”

“…The crystallite size was calculated using Debye-Scherer's equation (equation 1) below. [16] The average particle sizes, calculated by the This result indicates that, as the concentration of Mn 2+ ions increases, the size of the particles also increases:…”

Preparation of Palladium Supported on Ferric Oxide Nano-catalysts for Carbon Monoxide Oxidation in Low Temperature

“…To date, this reaction was mostly studied on supported noble metal catalysts like Au, Pt and Pd due to their high activities at low temperatures [4][5][6]. However, high prices and deactivation drawbacks of these metal catalysts limit applications in many fields [5,[7][8][9]. The deactivation was mainly originated from aggregation of active metal, coverage of carbonates and competitive adsorption between CO and moisture [10,11].…”

Facile synthesis of N doped ZnO Coral bundles for enhanced photocatalytic and antimicrobial activity

“…The process of doping nitrogen on metal oxide semiconductors like TiO 2 and ZnO has employed precursors like amino acid, NH 4 NO 3 , NH 3 , and urea 21–24 . Many of the procedures available for N (nitrogen) doping are on substrate materials, 25–26 and those which form powder morphology follow tiresome strategies, employing a number of precursors and templates 27 . Generally, ZnO is preferred over TiO 2 due to its low cost and higher quantum efficiency, 28–29 and there are number reports on the preparation of ZnO by simple precipitation, sol‐gel, hydrothermal, and combustion techniques 30–33 .…”

“…SUGANYA JOSEPHINE ANd ARUMUGAM powder morphology follow tiresome strategies, employing a number of precursors and templates. 27 Generally, ZnO is preferred over TiO 2 due to its low cost and higher quantum efficiency, [28][29] and there are number reports on the preparation of ZnO by simple precipitation, sol-gel, hydrothermal, and combustion techniques. [30][31][32][33] Herein, we found that only a very few reports employ (NH 4 ) 2 CO 3 (AC) as a precipitant for zinc oxide preparation, and to the best of our knowledge, the utilization of AC as a source for N doping of ZnO with controlled morphology remains unexplored in literature.…”