A kinetic model for photocatalytic degradation of organic contaminants in a thin-film TiO2 catalyst

2000 ◽  
Vol 34 (2) ◽  
pp. 407-416 ◽  
Author(s):  
H Chang
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Derya Tekin ◽  
Taner Tekin ◽  
Hakan Kiziltas

AbstractThe degradation of water pollutants with photocatalysts is one of the most studied subjects in the past 20 years. Although considerable studies have been completed in this field, kinetic model studies are still a major inadequacy. In this study, ZnO and Ag/ZnO thin film photocatalysts were synthesized and SEM-EDS, XRD and chronoamperometric measurements were used the characterization of photocatalysts. The network kinetic model was applied the photocatalytic degradation of Orange G using ZnO and Ag/ZnO thin film photocatalysts. The photocatalytic degradation of Orange G was investigated under the different reaction medium (initial dye concentrations, temperature, light intensity). It was found that the network kinetic model is the most appropriate model for the degradation of Orange G dye on the ZnO and Ag/ZnO thin film photocatalysts. The calculated adsorption equilibrium (KB) constant and activation energy of ZnO thin film photocatalyst are 0.0191 and 21.76 kj/mol, respectively. Additionally, the calculated values for Ag/ZnO thin film photocatalyst are 0.035 and 18.32 kj/mol. The general rate equations were determined for each photocatalysts.


2018 ◽  
Vol 15 (2) ◽  
pp. 188-196 ◽  
Author(s):  
Chengpeng Xu ◽  
Shengying Ye ◽  
Xiaolei Cui ◽  
Quan Zhang ◽  
Yan Liang

Background: Improper storage and raw materials make peanut oil susceptible to Aflatoxin B1 (AFB1). The semiconductor TiO2 photocatalysis technology is an effective technology which is widely used in sewage treatment, environmental protection and so on. Moreover, the photocatalytic efficiency can be improved by doping I. Method: The experiment is divided into two parts. In the first part, supported TiO2 thin film (STF) was prepared on the quartz glass tube (QGT) by the sol-gel and calcination method and the supported iodine doped supported TiO2 thin film (I-STF) was synthesized using potassium iodate solution. In the second part, the photocatalytic degradation of AFB1 was performed in a self-made photocatalytic reactor. The AFB1 was detected by ELISA kit. Results: The photocatalytic degradation of AFB1 has been proven to follow pseudo first-order reaction kinetics well (R2 > 0.95). The maximum degradation rate of 81.96%, which was reached at the optimum iodine concentration of 0.1mol/L, was 11.38% higher than that with undoped STF. The doping of iodine reduces the band-gap of TiO2, thereby increasing the photocatalytic response range. The proportion of Ti4+ in I-STF has decreased, which means that Ti4+ are replaced by I. The I-STF prepared at iodine concentration of 0.1mol/L has good photocatalytic properties.


2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Mohammad Hossein Habibi ◽  
Mohammad Khaledi Sardashti

Glass plate-supported nanostructure ZnO thin films were deposited by sol-gel spin coating. Films were preheated at275∘Cfor 10 minutes and annealed at 350, 450, and550∘Cfor 80 minutes. The ZnO thin films were transparent ca 80–90% in visible range and revealed that absorption edges at about 370 nm. Thec-axis orientation improves and the grain size increases which was indicated by an increase in intensity of the (002) peak at34.4∘in XRD corresponding to the hexagonal ZnO crystal. The photocatalytic degradation of X6G an anionic monoazo dye, in aqueous solutions, was investigated and the effects of some operational parameters such as the number of layer and reusability of ZnO nanostructure thin film were examined. The results showed that the five-layer coated glass surfaces have a very high photocatalytic performance.


2022 ◽  
Author(s):  
Feng Min ◽  
Zhengqing Wei ◽  
Zhen Yu ◽  
Yu-Ting Xiao ◽  
Shien Guo ◽  
...  

Both efficient charge separation and sufficiently exposed active sites are critical limiting for solar-driven organic contaminants degradation. Herein, we describe a hierarchical heterojunction photocatalyst fabricated by in situ growth of...


2021 ◽  
Author(s):  
Tongtong Zhang ◽  
Qi Yin ◽  
Menghan Zhang ◽  
Siyu Zhang ◽  
Yanning Shao ◽  
...  

Abstract A series of rGO/AgBr heterojunction photocatalysts were fabricated through a facile solvothermal method. The rGO/AgBr heterostructures were characterized by XPS, XRD, UV-Vis DRS, SEM, TEM, PL and the transient photocurrent responses. The XRD, SEM, XPS and TEM analyzes indicated that the graphene and silver bromide were successfully compounded without other impurities. The UV-Vis DRS exhibited that the composites have better optical properties than pure silver bromide. The PL and the transient photocurrent responses demonstrated that the addition of graphene significantly promotes the separation of photogenerated electrons and holes. Subsequently, the photocatalytic activities of rGO/AgBr composites were studied by degrading Rhodamine B (RhB). It turned out that the degradation rate of RhB by the rGO/AgBr heterojunction photocatalysts were significantly higher than that by pure AgBr. What’s more, to study the photocatalytic degradation mechanism of RhB by rGO/AgBr heterostructures, the trapping experiments were used to identify the main active components. This work confirmed that the photocatalytic degradation performance of the catalyst was greatly improved after doping graphene, which provided certain data support for degradation of organic contaminants in water.


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