Enhanced photocatalytic degradation of atrazine by platinized titanium dioxide under 352 nm irradiation

2016 ◽  
Vol 75 (5) ◽  
pp. 1128-1137 ◽  
Author(s):  
Shen-Ming Chen ◽  
Norman Lu ◽  
Jun-Yu Chen ◽  
Cheng-Yu Yang ◽  
Yun-Peng Yeh ◽  
...  

Simply coating 1 wt.% of platinum on titanium dioxide (TiO2) surface resulted in simple preparation of platinized TiO2 (Pt-TiO2). This study demonstrated the photodegradation of atrazine (ATZ) using either Pt-TiO2 or TiO2 as a photocatalyst under 352 nm light irradiation. The Pt-TiO2-catalyzed ATZ degradation reached 76% in 3 hours without adding H2O2 solution or aeration, which was more than 10% higher than the TiO2-catalyzed reaction. The decomposition product of Pt-TiO2-catalyzed ATZ degradation was mainly cyanuric acid. Thus, Pt-TiO2 as an effective photocatalyst has three main advantages in the photodegradation of ATZ under 352 nm irradiation. First, the coated Pt can facilitate the generation of appropriate amounts of OH radicals, so it can prevent the formation of over-oxidized TiO2. Second, aeration was not needed. Third, the excited electrons were mainly uni-directionally transferred to the catalyst surface to avoid recombination of electron-hole pairs.

2019 ◽  
Vol 1 (2) ◽  
pp. 161-164
Author(s):  
Moatsasem wdaah Alsalih

This study includes preparation of nanoparticles of titanium dioxide using the sol-gel method and then, the band gap was modified by solid-state reaction with (Antimony) Stibium Sb reductive compounds. Modification reduced the band gap separating energy levels between valance band (VB) and conduction band (CB), therefore; facilitating the transfer of excited electrons from (VB) to (CB). Absorption of the energy from incident photons having the same or larger energy than the energy of the band gap promote the formation of the couple (electron-hole). The resulting (e--h+) couple acts to produce (OH.) radicals. OH. radicals having a high capability to inhibition of glutathione S-transferase activity in Aedes aegypti, mosquitoes that adsorbed on the surface of the photocatalytic TiO2 as a new model of eco-friendly insecticide. 


2020 ◽  
Vol 10 (10) ◽  
pp. 3345
Author(s):  
Nguyen Thi Thu Thuy ◽  
Do Hoang Tung ◽  
Le Hong Manh ◽  
Joon Heon Kim ◽  
Sergey Ivanovich Kudryashov ◽  
...  

To enhance the effectiveness of TiO2 as a photocatalyst, it was believed that the drawbacks of the large bandgap and the rapid electron-hole recombination can be overcome by coupling TiO2 with plasmonic metal nanoparticles. The incorporation of the nanoparticles onto the TiO2 surface requires a suitable procedure to achieve the proper particle adhesion. In this work, we propose a simple, clean, and effective surface activation of TiO2 using plasma enhanced wet chemical surface treatment. Under only 5 min of plasma treatment in a 3% NH3/3% H2O2 solution, gold nanoparticles were found better adhered onto the TiO2 surface. Hence, the methylene blue degradation rate of the Au/TiO2 under sunlight treated was improved by a factor of 3.25 times in comparison to non-treated Au/TiO2 and by 13 times in comparison to the bare rutile TiO2.


2021 ◽  
Vol 11 (2) ◽  
Author(s):  
S. Ismat Shah ◽  
Sawsan A. Mahmoud ◽  
Samar H. Bendary ◽  
Ahmed K. Aboulgheit ◽  
A. A. Salem ◽  
...  

AbstractPulsed laser deposition facilitates the epitaxial deposition and growth of TiO2 at low temperature on hot substrate. In this study, nanosized nitrogen-doped TiO2 thin films were deposited on fabricated alumina disc-shaped and glass substrates. Textural properties of the fabricated disc and alumina disc-supported TiO2 were investigated using N2 adsorption–desorption isotherms, field emission scanning electron microscopy (FESEM), X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy. FESEM showed the presence of single crystals of TiO2 on the alumina disc. FTIR showed the presence of octahedral TiO2 and different hydroxyl groups on the surface which is responsible for the photoactivity and also showed the functional groups adsorbed on the catalyst surface after the photocatalytic degradation. The concentration of 2-chlorophenol and the photo-redox intermediate products as a function of irradiation time was determined. The concentration of the produced chloride ion during the photocatalytic degradation was determined by an ion chromatography. The results showed that the photocatalytic activity of the catalyst decreased upon cycling. The obtained results were compared with nanostructured TiO2 supported on glass substrate. Higher efficiency of 100% degradation was achieved for TiO2/Al2O3 catalyst, whereas about 70% degradation of 2-CP was achieved using TiO2/glass. Different photointermediates of 2-CP degradation have been identified for each cycle. The difference of intermediates is supported by the adsorbed fragments on the catalyst surface.


2021 ◽  
Vol 767 ◽  
pp. 138367
Author(s):  
Hengjun Gai ◽  
Haozhong Wang ◽  
Lei Liu ◽  
Bingxiao Feng ◽  
Meng Xiao ◽  
...  

2003 ◽  
Vol 68 (11) ◽  
pp. 2219-2230 ◽  
Author(s):  
Gabriel Čík ◽  
Milada Hubinová ◽  
František Šeršeň ◽  
Jozef Krištín ◽  
Monika Antošová

Degradation of 4-chlorophenol by reactive oxygen species was studied, the latter being generated by photo-assisted reactions of thiophene oligomers, synthesized in channels of the Na-ZSM-5 zeolite. The photoreaction was carried out in an aqueous suspension of photocatalyst, irradiated with visible light (λ > 400 nm). The spin-trapping method was used to detect the generated •OH radicals. The main products of the photodecomposition of 4-chlorophenol were found to be phenol, hydroquinone and maleic acid.


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