Effect of pretreatment temperature on the photocatalytic activity of microwave irradiated porous nanocrystalline ZnO

2015 ◽  
Vol 39 (1) ◽  
pp. 321-332 ◽  
Author(s):  
Tarek T. Ali ◽  
Katabathini Narasimharao ◽  
Ivan P. Parkin ◽  
Claire J. Carmalt ◽  
Sanjayan Sathasivam ◽  
...  

ZnO treated at 200 °C offered high photocatalytic degradation of methyl orange (99%) in a short time (90 min). The activity can be attributed to several factors including low crystallite size, high band gap energy and porosity.

2012 ◽  
Vol 622-623 ◽  
pp. 883-888
Author(s):  
Natkritta Boonprakob ◽  
Natda Wetchakun ◽  
Sukon Phanichphant ◽  
Jun Chen ◽  
Burapat Inceesungvorn

Nitrogen-loaded TiO2(N-loaded TiO2), a visible-light driven catalyst, was successfully synthesized by the modified sol-gel method. Physical characterizations of the as-prepared catalysts have been performed by using X-ray diffraction (XRD), Diffuse reflectance UVvisspectroscopy(DRUVvis), Raman spectroscopyand BETspecific surface areain order to obtain structure-activity relationship. Results from Raman spectroscopy clearly suggested that N atoms were incorporated into the TiO2crystal lattice as evidenced by the vibrational peak of TiN in TiO2-xNx.DR UVvis results also suggested that the nitrogen dopant might be responsible for narrowing the TiO2band gap energy, thus resulting in a shift towards the visiblelight region. Photocatalytic activity of N-loaded TiO2evaluated through the degradation of methyl orange (MO)under visible light irradiation (l> 400 nm) indicated that all N-loaded photocatalysts exhibited significantly higher activities than the unloaded TiO2and Degussa P25 TiO2. According to the results from DR UV-vis, XRD and BET studies, the enhanced photoactivity observed from N-loaded samples might be due to a decrease in TiO2band gap energy and/or changes in chemical and physical properties of the materials upon loading with nitrogen.


RSC Advances ◽  
2016 ◽  
Vol 6 (69) ◽  
pp. 64446-64449 ◽  
Author(s):  
Xiaosong Zhou ◽  
Bei Jin ◽  
Jin Luo ◽  
Xuyao Xu ◽  
Lingling Zhang ◽  
...  

Dramatic visible light photocatalytic activity was obtained for the degradation of methyl orange using TiO2 photocatalysts modified with polydopamine (PDA) nanospheres.


Author(s):  
Amirah Ahmad ◽  
Mohd Hasmizam Razali ◽  
Mazidah Mamat ◽  
Karimah Kassim ◽  
Khairul Anuar Mat Amin

In this study, functionalized-MWCNTs with 3-aminopropyltriethoxysilane (APTES) loaded titania nanoparticles (MWCNTs-APTES-TiO2) were prepared to investigate their physicochemical properties and photocatalytic activity for methyl orange (MO) degradation. The TiO2 nanoparticles, functionalized-MNCNT and composite powders were characterized by XRD, raman, and TEM. The results obtained proved that titania (TiO2) nanoparticles was successfully loaded on APTES-MWCNTs. The best photocatalytic degradation of methyl orange solution under UV light irradiation was recorded over MWCNTs-APTES-TiO2 (1:2), with 87% after 180 min. Kinetic analysis indicated that photocatalytic degradation of MO solution by MWCNTs-APTES-TiO2 obeyed second-order kinetic model (R2 > 0.95), supported by half-life equations and graph. The presence of carbon nanotubes accelerated the degradation of methyl orange due to inhibition of electron-hole recombination, the formation of additional hydroxyl radicals and functional groups of the latter had an inhibitory effect on the degradation of methyl orange. This study shows that the MWCNTs-APTES-TiO2 nanocomposites exhibit promising photocatalytic degradation against methyl orange.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Ghaida H. Munshi ◽  
Amal M. Ibrahim ◽  
Laila M. Al-Harbi

As the need to use green chemistry routes increases, environmentally friendly catalytic processes are a demand. One of the most important and abundant naturally occurring catalysts is chlorophyll. Chlorophyll is the first recognized catalyst; it is a reducing agent due to its electron-rich structure. The effects of spinach on the preparation of zinc oxide nanoparticles and the photocatalytic degradation of methyl orange and paraquat in sunlight and under a UV lamp and photocatalytic degradation in sunlight were studied. Different parameters of the catalytic preparation process and photocatalytic degradation process were studied. Characterization of differently prepared samples was carried out using different analytical techniques such as XRD, SEM, and EDX and finally the photocatalytic activity towards decomposition of methyl orange and paraquat.


2015 ◽  
Vol 3 (7) ◽  
pp. 3568-3575 ◽  
Author(s):  
Zameer Hussain Shah ◽  
Jiasheng Wang ◽  
Yuzhen Ge ◽  
Cui Wang ◽  
Wenxin Mao ◽  
...  

The role of CuO as a co-catalyst was studied on plasmonic photocatalysis of Ag/AgCl/TiO2, and it was found that the photocatalytic degradation of methyl orange and phenol under visible light was highly enhanced when CuO was incorporated into Ag/AgCl/TiO2.


2015 ◽  
Vol 1085 ◽  
pp. 187-191
Author(s):  
Аlina A. Pichugina ◽  
Svetlana A. Kuznetsova

The article demonstrates how time and speed of pressure growth in the course of microwave-hydrothermal processing affect surface morphology and photocatalytic activity of tin (II) oxide. The experiment proved that the materials’ pore size and pore volume influenced their sorption activity and the speed of photocatalytic degradation of methyl orange.


2012 ◽  
Vol 488-489 ◽  
pp. 22-26
Author(s):  
Lek Sikong ◽  
H. Panritdam ◽  
Juntima Chungsiriporn ◽  
S. Te-Chato

SnO2/N – doped TiO2photocatalysts were prepared by the modified sol-gel method. Tin tetrachloride pentahydrate, urea and polyethylene glycol were used as precursors and calcined at a temperature of 500 °C for 2 h for making powders. Different interstitial amount of nitrogen additives were in range of 0 to 40 mol%N. The XRD patterns show the TiO2nanocomposites are anatase phase. It was also apparent that doped nitrogen has an effect on crystallite size and band gap energy on absorbed light wavelength leading of enhancement of photocatalytic activity of TiO2composite nanoparticles. The result showed 20 mol%N of TiO2nanocomposites exhibited high photocatalytic activity, redshift in adsorption edge and a small crystallite size.


2011 ◽  
Vol 48-49 ◽  
pp. 149-152
Author(s):  
Li Li Yang ◽  
Jin Lei Chen ◽  
Wen Jie Zhang

TiO2 and CuZSM-5 were mixed together as photocatalyst in dealing with photocatalytic degradation of methyl orange. Adsorption and photocatalytic degradation properties of the CuZSM-5 zeolite and mixture of TiO2 and CuZSM-5 were investigated. The CuZSM-5 zeolite has no photocatalytic activity under the experimental conditions. Methyl orange decoloration rate was 65.4%, which was 9.60% higher than that without using CuZSM-5, when TiO2 and CuZSM-5 were at the optimum ratio of 3.13:1. An optimum TiO2 concentration of 250 mg/l occurred when using pure TiO2. However, when using TiO2-CuZSM-5 mixture, the decoloration rate continuously increased with increasing photocatalyst concentration. After 70 min of irradiation, 98.4% of the initial methyl orange decoloration was found using TiO2-CuZSM-5 mixture at TiO2 concentration of 250 mg/l.


2009 ◽  
Vol 79-82 ◽  
pp. 541-544 ◽  
Author(s):  
Li Ying Zhu ◽  
Xiao Ping Yang ◽  
Dong Hua Teng ◽  
Yun Hua Yu

Composites of Sm doped TiO2 nanoparticles dispersed on carbon nanofibers (Sm-TiO2/CNFs) with different Sm contents were prepared by preoxidation, hydrolyzation and calcination of Sm-TiO2 precursor/PAN nanofibers. The characterizations of SEM, EDX, XPS and XRD showed that the CNFs surface was loaded by Sm-TiO2 nanoparticles with a uniform size of about 10nm, existing as anatase. It was concluded from XPS results that Ti element exist as Ti4+ and Sm doping increased the content of absorbed oxygen in composites. The effect of Sm doping on the photocatalytic activity of the Sm-TiO2/CNFs composite was investigated by the photocatalytic degradation of methyl orange aqueous solution under UV irradiation. It was found that Sm doping could improve the photocatalytic property of Sm-TiO2/CNFs effectively compared with the undoped specimen, and the photocatalytic activity of the Sm-TiO2/CNFs samples enhanced firstly and then reduced with Sm content increasing.


2012 ◽  
Vol 485 ◽  
pp. 72-75
Author(s):  
Wen Jie Zhang ◽  
Jin Lei Chen

HZSM-5 was prepared from NaZSM-5 through treatment with NH4Cl. Adsorption and photocatalytic degradation of methyl orange was investigated as the factors of HZSM-5 amount and reaction time. Adsorption of methyl orange on the mixtures varied slightly in the range from 1% to 10% when using zeolite in the concentration up to 800 mg/l. Adsorption contributed a small percent in the total decoloration of methyl orange. With increasing HZSM-5 concentration in the solution, total decoloration rate changed in a wide range. The maximum decoloration value was obtained in HZSM-5 concentration of 104 mg/l. After 70 min of irradiation, methyl orange decoloration on the mixture reached 99.5%.


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