Mechanism of CeVO4/TiO2 Photocatalytic Degradation of VOCs under Visible Light Irradiation: Electrochemical, Photoluminescence and Active Oxygen Species Study

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.

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.


2012 ◽  
Vol 550-553 ◽  
pp. 149-152 ◽  
Author(s):  
Han Jie Huang ◽  
Wen Long She ◽  
Ling Wen Yang

In this work, a visible light-activated LaVO4/TiO2 composite photocatalyst has been successfully synthesized via a facile coupled method. The composite was characterized by powder X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS) and spin-trapping electron paramagnetic resonance (EPR). Based on the detection of active oxygen species, a visible light-induced photocatalytic degradation mechanism of benzene on LaVO4/TiO2 was proposed.


1999 ◽  
Vol 64 (1) ◽  
pp. 149-156 ◽  
Author(s):  
Gabriel Čík ◽  
František Šeršeň ◽  
Alena Bumbálová

The formation of reactive oxygen species due to irradiation by a visible light of the polythiophene deposited in ZSM-5 zeolite channels in aqueous medium has been studied. Polymerization of thiophene was carried out in zeolite channels after the ion-exchange reaction of Na+ for Fe3+. By means of EPR spectroscopy, the temporarily generated 1O2 in irradiated aqueous medium was proved. The formation of O2-• was confirmed by the reduction of Fe3+-cytochrome c. Irradiation led to the water reduction to hydrogen.


2020 ◽  
Vol 22 (1) ◽  
pp. 154
Author(s):  
Fasih Bintang Ilhami ◽  
Kai-Chen Peng ◽  
Yi-Shiuan Chang ◽  
Yihalem Abebe Alemayehu ◽  
Hsieh-Chih Tsai ◽  
...  

Development of stimuli-responsive supramolecular micelles that enable high levels of well-controlled drug release in cancer cells remains a grand challenge. Here, we encapsulated the antitumor drug doxorubicin (DOX) and pro-photosensitizer 5-aminolevulinic acid (5-ALA) within adenine-functionalized supramolecular micelles (A-PPG), in order to achieve effective drug delivery combined with photo-chemotherapy. The resulting DOX/5-ALA-loaded micelles exhibited excellent light and pH-responsive behavior in aqueous solution and high drug-entrapment stability in serum-rich media. A short duration (1–2 min) of laser irradiation with visible light induced the dissociation of the DOX/5-ALA complexes within the micelles, which disrupted micellular stability and resulted in rapid, immediate release of the physically entrapped drug from the micelles. In addition, in vitro assays of cellular reactive oxygen species generation and cellular internalization confirmed the drug-loaded micelles exhibited significantly enhanced cellular uptake after visible light irradiation, and that the light-triggered disassembly of micellar structures rapidly increased the production of reactive oxygen species within the cells. Importantly, flow cytometric analysis demonstrated that laser irradiation of cancer cells incubated with DOX/5-ALA-loaded A-PPG micelles effectively induced apoptotic cell death via endocytosis. Thus, this newly developed supramolecular system may offer a potential route towards improving the efficacy of synergistic chemotherapeutic approaches for cancer.


2019 ◽  
Vol 9 (10) ◽  
pp. 2563-2570 ◽  
Author(s):  
Yuanguo Xu ◽  
Feiyue Ge ◽  
Meng Xie ◽  
Shuquan Huang ◽  
Junchao Qian ◽  
...  

An in situ photo-Fenton-like and magnetic recycle system, BaFe12O19/Ag3PO4 has been constructed. BaFe12O19 can catalyze the conversion of H2O2 to generate ROSs (˙O2− and ˙OH radicals) on the surface of Ag3PO4.


2017 ◽  
Vol 46 (3) ◽  
pp. 685-696 ◽  
Author(s):  
Jagriti Gupta ◽  
Jeotikanta Mohapatra ◽  
D. Bahadur

The systemic diagram shows the mechanism of photocatalysis, bacterial inhibition and photodynamic therapy through the generation of reactive oxygen species.


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