Nanocrystalline ZnO Thin Film for Photocatalytic Purification of Water

Author(s):  
Sawsan A. Mahmoud ◽  
A. Abdel Aal ◽  
Ahmed K. Aboul-Gheit

A thin film ZnO nanostructured catalyst exhibited a significantly greater superiority for the photodegradation of 2, 4, 6-TCP in water over photolysis via irradiation with UV of 254 nm wavelength. This ZnO photocatalyst was prepared via Zn metal evaporation and deposition on a glass sheet followed by calcination ature from 350 to 500 °C and the calcination time from 1 to 2h shows via SEM photography a decrease of ZnO nanoparticales sizes sheet followed by calcination (oxidation). Increasing the calcination temperature from 350 to 500 °C and the calcination time from 1 to 2h shows via SEM photography a decrease of ZnO nanoparticales sizes as well as the shape of their crystals finer needles, for which the crystallinity enhances as revealed by XRD. 2, 4, 6-Trichlorophenol was used as a model pollutant in water. Its photolysis using UV only or photocatalysis using UV irradiation in presence of the ZnO thin film catalyst indicated aromatic intermediates, which suffered of Cl by OH, addition of OH in a bare carbon in the aromatic ring, whereas in Photocatalysis deeper oxidation products, e.g., quinones and hydroquinones were also formed.

2009 ◽  
Vol 29 (3) ◽  
pp. 831-835 ◽  
Author(s):  
A. Abdel Aal ◽  
Sawsan A. Mahmoud ◽  
Ahmed K. Aboul-Gheit

2020 ◽  
Vol 31 (9) ◽  
pp. 6948-6955
Author(s):  
Mustafa Özgür ◽  
Suat Pat ◽  
Reza Mohammadigharehbagh ◽  
Uğur Demirkol ◽  
Nihan Akkurt ◽  
...  

2021 ◽  
Vol 32 (3) ◽  
pp. 2696-2703
Author(s):  
Zexuan Guo ◽  
Man Zhao ◽  
Dayong Jiang ◽  
Jing Zhang ◽  
Chunyan Xu

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 397
Author(s):  
Yu-Chen Chang ◽  
Ying-Chung Chen ◽  
Bing-Rui Li ◽  
Wei-Che Shih ◽  
Jyun-Min Lin ◽  
...  

In this study, piezoelectric zinc oxide (ZnO) thin film was deposited on the Pt/Ti/SiNx/Si substrate to construct the FBAR device. The Pt/Ti multilayers were deposited on SiNx/Si as the bottom electrode and the Al thin film was deposited on the ZnO piezoelectric layer as the top electrode by a DC sputtering system. The ZnO thin film was deposited onto the Pt thin film by a radio frequency (RF) magnetron sputtering system. The cavity on back side for acoustic reflection of the FBAR device was achieved by KOH solution and reactive ion etching (RIE) processes. The crystalline structures and surface morphologies of the films were analyzed by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The optimized as-deposited ZnO thin films with preferred (002)-orientation were obtained under the sputtering power of 80 W and sputtering pressure of 20 mTorr. The crystalline characteristics of ZnO thin films and the frequency responses of the FBAR devices can be improved by using the rapid thermal annealing (RTA) process. The optimized annealing temperature and annealing time are 400 °C and 10 min, respectively. Finally, the FBAR devices with structure of Al/ZnO/Pt/Ti/SiNx/Si were fabricated. The frequency responses showed that the return loss of the FBAR device with RTA annealing was improved from −24.07 to −34.66 dB, and the electromechanical coupling coefficient (kt2) was improved from 1.73% to 3.02% with the resonance frequency of around 3.4 GHz.


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