scholarly journals Rapid evaluation of oxygen vacancies-enhanced photogeneration of the superoxide radical in nano-TiO2 suspensions

RSC Advances ◽  
2020 ◽  
Vol 10 (49) ◽  
pp. 29082-29089
Author(s):  
Wanchao Yu ◽  
Fengjie Chen ◽  
Yarui Wang ◽  
Lixia Zhao

Reactive oxygen species (ROS) play an important role in the photocatalytic degradation of pollutants and are closely related to the surface defects of a semiconductor.

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.


2018 ◽  
Vol 78 (6) ◽  
pp. 1390-1399 ◽  
Author(s):  
Wenshu Li ◽  
Peng Zhou ◽  
Jing Zhang ◽  
Yongli Zhang ◽  
Gucheng Zhang ◽  
...  

Abstract This study investigated the generation of reactive oxygen species (ROS) (O2−•, H2O2, and HO•) by promoting the Cu(II)/Cu(I) redox cycle with certain reducing agents (RAs) in aerobic aqueous solution, and benzoic acid (BA) was employed as indicator for the hydroxyl radical (HO•). Hydroxylamine (HA) can reduce Cu(II) to Cu(I) to induce chain reactions of copper species resulting in the generation of the superoxide radical (O2−•) and hydrogen peroxide (H2O2), and the intermediate Cu(I) can further activate H2O2 via a Fenton-like reaction to produce HO•, creating the remarkable BA degradation. O2 is indispensable, and unprotonated HA is the motive power in the O2/Cu/HA system. Moreover, pH is a crucial factor of the O2/Cu/HA system due to the protonated HA not being able to reduce Cu(II) into Cu(I). The oxidation of HA can be effectively induced by trace amounts of Cu(II), and both a higher HA dosage and a higher Cu(II) dosage can enhance H2O2 generation and BA degradation. In addition, some other RAs that can reduce Cu(II) into Cu(I) could replace HA in the O2/Cu/HA system to induce the generation of these ROS in aerobic aqueous solution.


2012 ◽  
Vol 217-219 ◽  
pp. 853-856 ◽  
Author(s):  
Han Jie Huang ◽  
Wen Long She ◽  
Ling Wen Yang

In this paper, CeVO4/TiO2 composite photocatalyst has been characterized by photoelectrochemical and reactive oxygen species trap techniques to reveal the mechanism for photocatalytic degradation of VOCs in gas-phase. Based on the measurement of flatband of the samples and the detection of reactive oxygen species, a visible light-induced photocatalytic degradation mechanism of VOCs on CeVO4/TiO2 is proposed.


2015 ◽  
Vol 158 ◽  
pp. 1-13 ◽  
Author(s):  
Fengmin Li ◽  
Zhi Liang ◽  
Xiang Zheng ◽  
Wei Zhao ◽  
Miao Wu ◽  
...  

2015 ◽  
Vol 12 (2) ◽  
pp. 026003 ◽  
Author(s):  
Pavel Takmakov ◽  
Kiersten Ruda ◽  
K Scott Phillips ◽  
Irada S Isayeva ◽  
Victor Krauthamer ◽  
...  

Author(s):  
Junye Ma ◽  
Zongsu Wei ◽  
Richard Spinney ◽  
Dionysios D. Dionysiou ◽  
Ruiyang Xiao

The superoxide radical (O2˙−) is an important reactive oxygen species (ROS) in diverse natural aquatic systems and engineered water treatment processes.


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