Photocatalytic degradation kinetics of cationic and anionic dyes using Au–ZnO nanorods: Role of pH for selective and simultaneous degradation of binary dye mixtures

Author(s):  
Shweta Verma ◽  
B. Tirumala Rao ◽  
R. Singh ◽  
R. Kaul
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ruifen Wang ◽  
Kaixuan Shi ◽  
Dong Huang ◽  
Jing Zhang ◽  
Shengli An

AbstractPoriferous TiO2/GO (denoted as TGO-x%) photocatalysts with ultrathin grapheme oxide (GO) layer were prepared by a hydrothermal method, the adsorption and photocatalytic degradation and its kinetics about Methylene blue(MB) were studied systematically. All the TGO-x% showed improved adsorption and photodegradation performance. TGO-25% had excellent adsorptivity while TGO-20% exhibit the highest visible light photocatalytic degradation activity. The adsorption capacity for TGO-25% was 20.25 mg/gcatalyst along with the k1 was about 0.03393 min·gcatalyst/mg, this enhancement was mainly owing to the strong adsorption capacity of GO and the stacking structure of sheets and nanoparticles. GO sheets prevented the agglomeration of TiO2 particles and TiO2 nanoparticles also prevented the agglomeration of GO sheets, which could provides greater surface area. Besides, the remarkably superior photodegradation activity of TiO2/GO composites is mainly attribute to the strong absorption of visible light and the effective charge separation revealed by the photoluminescence, the total removal rate of MB is 97.5% after 35 min adsorption and 140 min degradation, which is 3.5 times higher than that of TiO2.


2011 ◽  
Vol 30 (3) ◽  
pp. 318-325 ◽  
Author(s):  
J.A. Cortés ◽  
M.T. Alarcón-Herrera ◽  
M. Villicaña-Méndez ◽  
J. González-Hernández ◽  
J.F. Pérez-Robles

2014 ◽  
Vol 955-959 ◽  
pp. 2334-2339
Author(s):  
Pin Wen Wang

The photodegradation behavior of bisphenol AF (BPAF) in TiO2 suspension was investigated. The influence of dissolved oxygen, TiO2 dosage, fluoride, and initial BPAF concentration on the degradation of BPAF was studied and described in details. The main purposes were to clarify the degradation kinetics of BPAF and quantify the fluoride concentration during the degradation. At an initial concentration of 40 mol/L, more than 97% of TOC was removed efficiency was achieved within 540 min irradiation, and the concentration of fluoride was 0.98 mg/L. Degradation of BPAF followed the Langmuir–Hinshelwood kinetics rate model and the reaction rate constant kre was 1.21 μM/min. The results obtained indicated that TiO2 photocatalytic degradation is a highly effective way to remove BPAF without any generation of more toxic products or fluoride pollution.


2012 ◽  
Vol 3 (4) ◽  
pp. 443-449 ◽  
Author(s):  
A. Hu ◽  
X. Zhang ◽  
D. Luong ◽  
K. D. Oakes ◽  
M. R. Servos ◽  
...  

2012 ◽  
Vol 441 ◽  
pp. 598-602 ◽  
Author(s):  
Bo Yu ◽  
Zai Sheng Cai ◽  
Wei Ming Wang ◽  
Chun Chun Lu

The photocatalyst of Ag doped TiO2 in liquid state was applied to decolorize the Reactive Red 3BS under UV irradiation. The rate of photocatalytic degradation of the dye was improved with increasing the concentration of catalyst from 1 g/L to 8 g/L. But as a result of light attenuation for the rising catalyst concentration, the rate of reaction was constant at 8-12 g/L of the catalyst concentration. The rate of dye photocatalytic degradation decreased with increasing initial concentration of dye. The kinetics of photocatalytic reaction was also studied. The results showed that degradation reaction is congruent with an apparent first-order kinetic equation, and the relationship between apparent reaction rate and initial dye concentration fits approximately a negative second-order kinetic relationship.


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