Titanium Dioxide Nanoparticle Photocatalysed Degradation of Ibuprofen and Naproxen in Water: Competing Hydroxyl Radical Attack and Oxidative Decarboxylation by Semiconductor Holes

2018 ◽  
Vol 3 (39) ◽  
pp. 10915-10924 ◽  
Author(s):  
Andreia Romeiro ◽  
M. Emília Azenha ◽  
Moisés Canle ◽  
Victor H. N. Rodrigues ◽  
José P. Da Silva ◽  
...  
2019 ◽  
Author(s):  
Jason A. Coral ◽  
Christopher L. Kitchens

ABSTRACTIncreased use of titanium dioxide (TiO2) nanoparticles in different applications has increased risk for adverse environmental implications based on an elevated likelihood of organism exposure. Anatase TiO2 is photoactive with exposure to ultraviolet light. TiO2 nanoparticle exposure to UV-A radiation in aquatic environments generates hydroxyl radical species, which may ultimately be responsible increased organism toxicity. The present research demonstrates that the rate of radical generation heavily depends on exposure conditions, particularly the presence of natural organic matter (NOM). Environmentally relevant concentrations of TiO2 nanoparticles were co-exposed to increasing NOM amounts (measured as concentration of dissolved organic carbon (DOC)) and UV-A intensities. Hydroxyl radical generation rate was determined using fluorescence spectroscopy. Radical generation rate was positively correlated to increases in TiO2 concentration and UV-A intensity, and negatively correlated to increased DOC concentration. Nanoparticle aggregation over time and decrease in light transmission from NOM had negligible contributions to the generation rate. This suggests the decreased radical generation rate is a result of radical quenching by NOM functionalities. D. magna toxicity to hydroxyl radicals is also demonstrated to decreased following the addition of DOC. These results correlate with the rate generation data, indicating that DOC provides rate attenuation that is protection to organisms. These conclusions demonstrate the importance considering exposure conditions during TiO2 toxicity testing, and during TiO2 waste management and regulatory decisions.


Author(s):  
Liyan Yang ◽  
Jun Ma ◽  
Weibing Zhong ◽  
Qiongzhen Liu ◽  
Mu fang Li ◽  
...  

The fabric-based piezoresistive sensors have demonstrated great potentials in the application of human motion and health detection. However, the conductive polymers of the sensing units are easily influenced by high...


Author(s):  
Hessameddin Mortazavi ◽  
Hossein Omidi-Ardali ◽  
Seyed Asadollah Amini ◽  
Javad Saffari-Chaleshtori ◽  
Keihan Ghatreh Samani

2015 ◽  
Vol 103 ◽  
pp. 51-58 ◽  
Author(s):  
Giovanni De Filpo ◽  
Anna Maria Palermo ◽  
Rosamaria Munno ◽  
Lucia Molinaro ◽  
Patrizia Formoso ◽  
...  

Author(s):  
Erfan Rezvani Ghomi ◽  
Saied Nouri Khorasani ◽  
Mohammad Dinari ◽  
Shahla Ataei ◽  
Rasoul Esmaeely Neisiany

2021 ◽  
Author(s):  
Yahya Absalan ◽  
Nazanin Noroozi Shad ◽  
Mostafa Gholizadeh

Abstract Different types of the amino acids (Glutamine, Glycine, Alanine) were used to coordinate TiCl3 in order to investigating the best precursor for synthesis of TiO2. Also, a full investigation was carried out to synthesis four different structures of TiO2 nanoparticles [TiO2 (A0.8R0.2), TiO2 (A0.6R0.4), TiO2 (Anatase), and TiO2 (Rutile)]. Oxidation of derivatives alcohol to their corresponding aldehyde through the obtained nanoparticles, as a photocatalyst, under UV light was considered to investigate the best structure of TiO2. Different physical-chemical analyses were applied to investigate the result. The result showed that the titanium dioxide nanoparticle, synthesized from glycine was obtained at the least temperature and was chosen as a precursor to synthesis of four different types of TiO2. All the synthesized TiO2 were applied for oxidation of benzyl alcohols into benzaldehyde, as a test, and TiO2 (A0.6R0.4) could give the best result (87% efficiency). Then it was used to oxidize benzyl alcohol, 4-cholorobenzyl alcohol, 4-nitrobenzyl alcohol and 4-methoxybenzyl alcohol to their corresponding aldehyde and efficiency were 74, 92, 87, and 65% respectively.


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