Preparation and characterization of ZnO nanocrystallines in the presence of an ionic liquid using microwave irradiation and photocatalytic activity

Abstract

Fast, simple and template-free method is proposed for preparation of ZnO nanocrystallines in the presence of 1-ethyl-3-methylimidazolium ethyl sulfate, [EMIM][EtSO 4 ], a room-temperature ionic liquid (RTIL) under microwave irradiation. The powder X-ray diffraction (XRD) studies display that products are excellently crystallized in the form of wurtzite hexagonal structure. Energy dispersive X-ray spectroscopy (EDX) investigations reveal that the products are extremely pure. The results obtained by scanning electron microscopy (SEM) demonstrate that mean size of ZnO nanocrystallines decreases with microwave irradiation time and the RTIL content of media. Diffuse reflectance spectra (DRS) of the ZnO nanocrystallines shows blue shift relative to the bulk ZnO, which can be attributed to quantum confinement effect of ZnO nanocrystallines. A possible formation mechanism of the ZnO nanocrystallines in aqueous solution of the RTIL is presented. Photocatalytic activity of the ZnO nanocrystallines towards photodegradation of methylene blue (MB) was carried out. The results demonstrate that photocatalytic activity of the ZnO nanocrystallines increases with microwave irradiation time and the RTIL content of media.

Photocatalytic Degradation of Municipal Wastewater and Brilliant Blue Dye Using Hydrothermally Synthesized Surface-Modified Silver-Doped ZnO Designer Particles

“…ZnO is known as an important semiconductor, which has been studied extensively in the past few years due to its fundamental and technological characteristics. Its various attractive properties, such as wide-band gap (3.37 eV), large excitation-binding energy (60 meV), and excellent chemical stability suggest a host of possible practical applications as gas sensors [3], ceramics [4], field emission devices [5], luminescent materials [6], biomedical [7], and photocatalysis [8]. Therefore, ZnO has been considered as one of the important materials, and its applications are expanding continuously [9].…”

Preparation of TiO2/SiO2 nanocomposite with non-ionic surfactants via sol-gel process and their photocatalytic study

“…TiO 2 powders possess interesting optical, dielectrical, and catalytical properties, which results in industrial applications 16,18 . In recent years great efforts have been devoted to the study of TiO 2 materials for photocatalytic degradation of organic and inorganic contaminants of water and air [19][20] . The synthesis of TiO 2 by the sol-gel method has proven to be a very useful tool for photo-induced molecular reactions to take place on a titanium dioxide surface 21 .…”

The Microwave‐Assisted Ionic‐Liquid Method: A Promising Methodology in Nanomaterials

“…Many reports on the preparation of metal oxide nanostructures by using this rapid method have been published. [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] It is widely known that zinc oxide (ZnO) is an important wide-bandgap II-VI semiconducting material and is widely used in the optoelectronics field. The application of the microwave-assisted ionic-liquid method in the synthesis of ZnO nanostructures was first carried out in our previous study.…”

“…[16,17] Recently, nanocrystalline ZnO with high photocatalytic activity was prepared under microwave irradiation in the presence of a room-temperature ionic liquid, 1-ethyl-3-methylimidazolium ethyl sulfate, 4 ]. [18] Unfortunately, the intrinsic reaction mechanism between the ionic liquid and ZnO is not clear yet and still needs to be further explored in detail.…”

“…In addition, Zn(OH)F nanofibers were obtained from Zn 5 (OH) 8 4 ]. [18] The as-prepared Zn(OH)F fibers were 80-200 nm in diameter and several micrometers in length. It was proposed that a hydrogen-bonding p-p stacking mechanism was responsible for the one-dimensional structure of Zn(OH)F. [21] They indicated that the F-F distance in the BF 4 À anion (about 2.28 ) is close to the distance (ca.…”