Porous TiO2 Film Electrode Used for Photoelectrocatalytic Degradation of Methyl Orange in NaHCO3 Solution

2011 ◽  
Vol 230-232 ◽  
pp. 126-130
Author(s):  
Wen Jie Zhang ◽  
Ke Xin Li

PEG1000 was used as template to prepare porous TiO2 film by sol-gel method. The functions of applied potential and concentration of NaHCO3 to the photoelectrocatalytic degradation of methyl orange on porous and smooth TiO2 films were investigated. Methyl orange degradation rate has two optimal values at the applied potential of 0.8 V and 1.8 V. The addition of PEG may have negative effect on photoelectrocatalytic activity of TiO2 film. The degradation rate increases with increasing NaHCO3 concentration from 0 up to 0.05 mol/l, and then it declines after further increase of electrolyte concentration. After 100 min of reaction, the degradation rates on the films prepared without and with PEG addition are 63.78% and 65.22%, respectively.

2012 ◽  
Vol 487 ◽  
pp. 635-639
Author(s):  
Wen Jie Zhang ◽  
Hong Liang Xin ◽  
Hong Bo He

Porous and smooth TiO2 film electrodes prepared by sol-gel method were used on methyl orange degradation by an electro-assisted photocatalytic degradation process. Methyl orange cannot be degraded under applied potential solely below 2.0 V. When the applied potential was below 1.3 V, methyl orange degradation rates on porous TiO2 film increased from 5% at 0 V to 65.3% at 1.3 V, and degradation rates on smooth TiO2 film changed from 2.2% at 0 V to 61.1% at 1.3 V. Electro-assisted photocatalytic degradation rate on porous film was better than that on smooth film in the whole electrolyte concentration range. Electro-assisted degradation exhibited the same rising trend along with reaction time on the porous and smooth films.


2011 ◽  
Vol 48-49 ◽  
pp. 345-348
Author(s):  
Li Li Yang ◽  
Yan Liang Qu ◽  
Wen Jie Zhang

A co-sol-gel method was used to prepare SiO2-doped TiO2. The amount of ethyl silicate added into the precursor, calcination temperature and time, adsorption equilibrium, and photocatalytic activity of the material were investigated as the factor of degradation efficiency. With the optimum composition of the precursor, the prepared gel calcinated at 500 oC for 3 h showed the highest photocatalytic activity. After 30 min stirring to reach adsorption equilibrium, adsorption contributed less than 2% to the total decoloration of methyl orange on the SiO2-doped TiO2 material. Photocatalytic methyl orange degradation continued with increasing irradiation time. Methyl orange degradation rates after 30 min and 100 min were 31.1% and 96.9%, respectively.


2012 ◽  
Vol 424-425 ◽  
pp. 981-984
Author(s):  
Feng Qi Li ◽  
Wen Jie Zhang

When potential was less than 1.2 V, electro-degradation rate was not more than 1.2% on both the films prepared using PEG or not. The film prepared with addition of PEG showed better degradation rates in the whole potential range than the film prepared without using of PEG. The highest degradation rates existed at 1.1 V of applied potential for both of the film electrodes, where degradation rate on film with PEG was 93.6% and the rate was 92.2% on the film without PEG. Methyl orange degradation rates increased with increasing KCl concentration from 0 to 0.7 mol/l, while degradation rates dropped down at even higher potential. Degradation rates increased with prolonged irradiation time for both of the two film electrodes.


2012 ◽  
Vol 433-440 ◽  
pp. 411-415
Author(s):  
Wen Jie Zhang ◽  
Ke Xin Li ◽  
Jia Wei Bai

Porous TiO2 film was prepared by a sol-gel method using PEG1000 as pore forming template. The porous film and normal film were used as electrodes in a photoelectrocatalytic reactor. The functions of applied potential and concentration of NaH2PO4 to the photoelectrocatalytic degradation process of methyl orange were investigated. The results show that methyl orange cannot be degraded solely by the applied potential. Under the applied potential of 2 V, 49.9% of the initial dye can be removed on the normal TiO2 film electrode, which is much better than the 31.1% removal rate on the porous TiO2 film electrode. The normal TiO2 film electrode has better performance than the porous TiO2 film in the whole NaH2PO4 concentration range. After 80 min of reaction, degradation rate is 93.7% on the normal TiO2 film electrode. After 100 min of reaction, degradation rate is 89.7% on the porous TiO2 film electrode.


2012 ◽  
Vol 465 ◽  
pp. 192-197 ◽  
Author(s):  
Lu Sheng Chen ◽  
Yan Yan Liu ◽  
Huai Xiang Li ◽  
Chao Liu ◽  
Kang Wu

In this work, F-Sb codoped SnO2film electrode material has been prepared and used as an anode on titanium (Ti) substrate for degradation of methyl orange. The emphasis is laid on the effect of univalent cations fluoride doped during preparation of F-Sn codoped SnO2composites by sol gel method. The facts show that univalent cations fluoride could affects the electro-catalytic degradation rate of methyl orange by F-Sb codoped composite film on the Ti electrode. A promotion to the degradation rates of methyl orange could be observed when KF or NH4F was used as codopant but other fluoride codopant such as LiF, NaF or HF could slow the methyl orange degradation. X-ray diffraction (XRD) and x-ray photo-electron spectroscopy (XPS) were used to study structures and composition of the anode surface.


2010 ◽  
Vol 26-28 ◽  
pp. 489-492
Author(s):  
Xuan Xiao ◽  
Jia Wei Bai ◽  
Wen Jie Zhang ◽  
Yuan Di Li

Photoelectrocatalytic (PEC) degradation efficiencies of a suspended TiO2 and Ti electrodes composite system in different ammonium salt solutions were investigated. Electrolyte type and concentration as well as the applied potential on the Ti electrodes had significant effects on photoelectrocatalytic degradation and electro-degradation efficiencies. PEC degradation and electro-degradation of methyl orange increased with increasing applied potential and electrolyte concentration. PEC degradation is much more powerful than electro-degradation. PEC degradation efficiency in (NH4)3PO4•3H2O solution is the highest 93.4%, whereas the efficiency in NH4Cl solution shows the worst 73.1%, which is even less than that of photocatalytic process alone. PEC degradation efficiencies in (NH4)2SO4 and NH4HCO3 solutions are 88.8% and 85.9% respectively, indicating no noticeable improvement compared with photocatalytic process.


2012 ◽  
Vol 457-458 ◽  
pp. 521-524 ◽  
Author(s):  
Wen Jie Zhang ◽  
Qian Li ◽  
Hong Bo He

The functions of applied potential to the photoelectrocatalytic degradation process of methyl orange were investigated. When using 0.05 M NaCl and under different applied potentials, the degradation rate increased obviously with increasing applied potential. When the applied potential was between 0.6 V-1.0 V, the degradation rate was enhanced drastically. The detected current values got larger as the applied potential increased from 0 up to 1.2 V. There was no direct electro-degradation to the dye in the solution. The applied potential and the irradiated light had synergetic effect when they were applied to the solution at the same time. While after irradiation for 0 to 60 min, with the increasing reaction time, methyl orange absorption peak intensity shrank obviously. The azo and benzene groups in methyl orange degraded totally under photocatalytic process.


2012 ◽  
Vol 457-458 ◽  
pp. 1169-1172
Author(s):  
Wen Jie Zhang ◽  
Mei Ling Hu ◽  
Hong Bo He

Porous and smooth TiO2 film electrodes prepared by sol-gel method were used on methyl orange degradation by an electro-assisted photocatalytic degradation process. When using the applied potential along, there was no obvious degradation of methyl orange whether using TiO2 film electrode prepared using PEG template or not. The largest difference between the two electrodes appears at potential of 0.7 V in 0.05 mol/l NaCl solution, and the porous electrode shows better degradation activity in electro-assisted photocatalytic degradation. When NaCl concentration was 0.07 mol/l, degradation rates on porous and smooth film electrodes were 51.16% and 32.35 %, respectively. After 100 min of irradiation, 90% of the methyl orange degraded on the porous TiO2 film electrode, and 79.87% of the methyl orange degraded on the smooth TiO2 film electrode.


2011 ◽  
Vol 213 ◽  
pp. 63-67
Author(s):  
Wen Jie Zhang ◽  
Xin Sun ◽  
Nan Ge

In order to improve the photocatalytic activity of TiO2, the optimal catalytic conditions of TiO2 and niobate as well as the composite TiO2 and niobate photocatalyst were studied. 10 mg/l of methyl orange solution was taken as imitated waste water. The results indicated that the optimum dosage of TiO2 was 0.8 g/l. The optimal calcination temperature to prepare lanthanum niobate was 900 oC. n(La):n(Nb) was in the range of 0.6:1−3:1, and the photocatalyst prepared in the ratio of 1.4:1 showed the highest activity. The results also showed that, TiO2-lanthanum niobate composite prepared by solid-state reaction method showed better photocatalytic activity on methyl orange degradation compared with pure TiO2. After 120 minutes of irradiation, methyl orange degradation rate reached 94.2 % when using the composite photocatalyst.


2014 ◽  
Vol 955-959 ◽  
pp. 112-115
Author(s):  
Li Wang ◽  
Dong Mei Jia ◽  
Zeng Qiang Zhao

Titanium dioxide (TiO2) coating was prepared through dipping stainless steel net into titanium dioxide sol and then extracting it. The photocatalytic activities for all titanium dioxide coatings were tested by methyl orange degradation under ultraviolet and visible light irradiation. The photo-absorption property was determined by UV-Vis spectrophotometer. The titanium dioxide coating is photo-catalytically reactive for the degradation of methyl orange. The photo-catalytic activity is influenced by extraction times, degradation time, doping element and light source. La-doped titanium dioxide exhibits the best photocatalytic activity in comparison with undoped, V-doped and La-V-codoped ones. The degradation rate of methyl orange by La-doped titanium dioxide coating reaches 92% after 70 minutes irradiation under ultraviolet light.


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