Nano-ZnO Photocatalytic Kinetics Based on Photo-Layer Model

2012 ◽  
Vol 550-553 ◽  
pp. 2819-2823
Author(s):  
Hang Xu ◽  
Min Yue Li

Nano-ZnO powders were prepared through gel-sol method with zinc acetate and lithium hydroxide as crude material. Nano-ZnO, as photo-catalyst, was used to decompose Methylene Blue at air lift circulating reactor and Photo-Layer model to describe photocatalytic kinetics. The results show that nano-ZnO has a integrate crystal and its size is 6.6nm with the best photocatalytic performance, when calcined at 350oC. The best ZnO dosage is 0.1g/L with 97% Methylene Blue removal after 30min. The photocatalytic process was the control step in chemical reaction. The •OH concentration inside the photo-layer in different reaction condition were calculated according to Photo-Layer model.

2012 ◽  
Vol 476-478 ◽  
pp. 1910-1914 ◽  
Author(s):  
Hang Xu ◽  
Mei Li ◽  
Ju Kun Wang

Nano-ZnO powder were prepared through gel-sol method with zinc acetate and lithium hydroxide as crude material. Nano-ZnO was analyzed by XRD, SEM, TEM, UV-Vis and determined photocatalytic activity at photocatalytic reactor. The results show that nano-ZnO has a integrate crystal and its size is 6.6nm with the best photocatalytic performance, when calcined at 350oC. The best ZnO dosage is 0.1g/L with 97% Methylene Blue removal after 30min. Compared with different photocatalytic reactor, the airlift reactor is obviously better than bubbling reactor and stirring reactor.


2014 ◽  
Vol 953-954 ◽  
pp. 999-1002
Author(s):  
Qing Ming Meng ◽  
Jian Wang ◽  
Bao Dong Zhu ◽  
Jian Wei Zhang ◽  
Yuan Yuan Wang

Nano-ZnO with high photocatalytic performance was prepared by paralled flaw precipitation method under ultrasonic radiation with Zn(NO3)2·6H2O and NH3·H2O as raw materials. The prepared samples were characterized by XRD, SEM and TG/DTA. The decolorization of methylene blue solution as model reaction, the effect of calcining temperature on the structure and photocatalytic performance of the samples were investigated. The results show that nano-ZnO with well crystal property and uniform size distribution, prepared by calcining the precursor at 300 °C for 2 h, had the average diameter of about 38 nm. When 100 mL methylene blue solution with 10 mg/L of mass concentration is treated with the nano-ZnO photocatalyst for 60 min, the decolorizing efficiency of the methylene blue solution reached 62.5 %.


2011 ◽  
Vol 194-196 ◽  
pp. 385-388
Author(s):  
Hong Juan Wang ◽  
Feng Qiang Sun ◽  
Ming Zhong Ren ◽  
Qing Wei Guo

Nanoporous SnO2with high photocatalytic activity has been successfully prepared by a photochemical method, using SnCl2aqueous solution as a precursor. The as-synthesized sample was characterized by XRD, N2 adsorption-desorption and UV-vis. The photocatalytic activity of the sample was evaluated by degrading methylene blue (MB) aqueous solution under the UV light source and was compared with that of the commercial titania (Degussa P25). The results showed that the produced SnO2can degrade MB solution quickly and has comparative photocatalytic performance with P25 for degrading MB. This facile method supplies an effective way to prepare SnO2photocatalyst.


2014 ◽  
Vol 608 ◽  
pp. 224-229 ◽  
Author(s):  
Potjanaporn Chaengchawi ◽  
Karn Serivalsatit ◽  
Pornapa Sujaridworakun

A visible-light responsive CdS/ZnO nanocomposite photocatalyst was successfully synthesized by precipitation of CdS nanoparticles, using Cd (NO3)2 and Na2S as starting materials, on ZnO nanoparticles and then calcined at 400°C for 2 hours. The effects of the mole ratio of CdS and ZnO in the composites on their phase, morphology, and surface area were investigated by X-ray Diffraction (XRD), scanning electron microscope (SEM), Brunauer Emmett Teller method (BET), respectively. The photocatalytic degradation of methylene blue solution in the presence of composite products under visible-light irradiation was investigated. The results showed that the mole ratio of CdS and ZnO played a significant role on photocatalytic performance. The highest photocatalytic activity was obtained from the CdS/ZnO nanocomposite with mole ratio of 1:4, which is higher than that of pure CdS and pure ZnO.


2014 ◽  
Vol 896 ◽  
pp. 541-544
Author(s):  
Is Fatimah ◽  
N. Nunani Yuyun

ZnO-SiO2/Laponite was prepared by sol-gel preparation procedure consit of SiO2 pillarization to laponite followed by ZnO dispersion by using zinc acetate as precursor. The obtained material was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), diffuse reflectance UV-Visible (DRUV-Vis) and N2 adsorption-desorption analysis. The photocatalytic performance of the amterial in methylene blue decolorization was also investigated. Compared with ZnO-SiO2 nanoparticles, it is concluded that ZnO-SiO2/Laponite possess higher photocatalytic activity which obey Temkin isotherm model.


2018 ◽  
Vol 42 (13) ◽  
pp. 11109-11116 ◽  
Author(s):  
R. Salimi ◽  
A. A. Sabbagh Alvani ◽  
N. Naseri ◽  
S. F. Du ◽  
D. Poelman

A new plasmonic Ag hybridized CuWO4/WO3 heterostructured nanocomposite was successfully synthesized via a ligand-assisted sol gel method and the photocatalytic activity was evaluated by photo-degradation of methylene blue (MB) under visible light irradiation.


RSC Advances ◽  
2017 ◽  
Vol 7 (41) ◽  
pp. 25314-25324 ◽  
Author(s):  
Lin Xiao ◽  
Li Youji ◽  
Chen Feitai ◽  
Xu Peng ◽  
Li Ming

A highly efficient and elaborately structured visible-light-driven catalyst composed of mesoporous TiO2 (MT) doped with Ag+-coated graphene (MT-Ag/GR) has been successfully fabricated by a sol–gel and solvothermal method.


Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 880 ◽  
Author(s):  
Feidias Bairamis ◽  
Ioannis Konstantinou ◽  
Dimitrios Petrakis ◽  
Tiverios Vaimakis

TiO2/g-C3N4 (GNT) fibers with 1%, 2.5% and 5% (wt%) ratios have been synthesized via one-step electrospinning using polyvinylpyrrolidone (PVP) polymer. Results showed mesoporous fibrous catalysts consisted of anatase (80.0–85.1%) and rutile phase (14.9–20.0%), with diameter between 200–300 nm and band gap lower than 3.0 eV confirming the absorption shift to visible-light region. The formation of •OH radicals and methylene blue dye degradation increases as the g-C3N4 doping percent also increases, following the trend ΤiO2 < GNT1% ≈ GNT2.5% < GNT5%. A z-scheme mechanism is attributed to the photocatalytic performance confirming the potential for green chemistry and environmental technology applications.


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