scholarly journals Enhanced Photocatalytic Degradation of Caffeine Using Titanium Dioxide Photocatalyst Immobilized on Circular Glass Sheets under Ultraviolet C Irradiation

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 964
Author(s):  
Rattana Muangmora ◽  
Patiya Kemacheevakul ◽  
Patiparn Punyapalakul ◽  
Surawut Chuangchote

This work presents the development of titanium dioxide (TiO2) film immobilized on circular glass sheets for photocatalytic degradation of caffeine under ultraviolet C (UVC) irradiation. TiO2 was synthesized through the ultrasonic-assisted sol–gel method and immobilized on circular glass sheets by the doctor blade technique. Polyvinylpyrrolidone (PVP) was used to mix with the TiO2 precursor solution to enhance film adhesion on the glass surface. TiO2 film was mainly composed of anatase phase with a small amount of rutile phase. Caffeine removal was found to increase with increasing irradiation time. Caffeine (20 mg/L) in the synthetic wastewater could not be detected after 3 h of UVC irradiation. The reaction rate of caffeine degradation followed the pseudo-first-order model. The concentrated caffeine solutions required a longer irradiation time for degradation. The used TiO2-coated glass sheets could be easily separated from the treated wastewater and reusable. The caffeine removal efficiency of TiO2-coated glass sheets in each cycle maintained a high level (~100%) during fifteen consecutive cycles.

2008 ◽  
Vol 5 (2) ◽  
pp. 219-223 ◽  
Author(s):  
Abbas J. Attia ◽  
Salih H. Kadhim ◽  
Falah H. Hussein

Photodegradation of a real textile dyeing wastewater taken from Hilla textile factory in Babylon Governorate, Iraq have been investigated. Photocatalytic degradation was carried out over suspensions of titanium dioxide or zinc oxide under ultraviolet irradiation. Photodegradation percentage was followed spectrophometrically by the measurements of absorbance at λmax equal to 380 nm. The rate of photodegradation increased linearly with time of irradiation when titanium dioxide or zinc oxide was used. A maximum color removal of 96% was achieved after irradiation time of 2.5 hours when titanium dioxide used at 303K and 82% color reduction was observed when zinc oxide used for the same period and at the same temperature. The effect of temperature on the efficiency of photodegradation of dyestuff was also studied. The activation energy of photodegradation was calculated and found to be equal to 21 ± 1 kJ mol-1 on titanium dioxide and 24 ± 1 kJ mol-1 on zinc oxide.


2013 ◽  
Vol 641-642 ◽  
pp. 11-17 ◽  
Author(s):  
Zhi Peng Meng ◽  
Fu Xin Zhong ◽  
Dan Yu Wang ◽  
Zhong Ming Zhang ◽  
Hua Ying Li ◽  
...  

This paper presents a novel approach for preparing titanium dioxide nanotube arrays (TNTs) loaded with highly dispersed Br through an ultrasound aided photochemical route. The content of Br doped on the arrays was controlled by changing the concentration of NaBr and the ultrasound time. The Br doped TiO2nanotube arrays were characterized by SEM, XRD and UV–Vis spectrum. Doping the bromine did not basically affect the morphology of the surface of the TNTs, but part of the anatase phase transformed into rutile phase, which led to the formation of the mixed crystal and increased the photocatalytic activity. The results showed that Br doping significantly enhanced the photocatalytic degradation rate of titanium dioxide nanotube arrays under UV-light irradiation. The main factors which affected photocatalytic degradation of sugar wastewater were the illumination time and pH. The results showed that the longer the exposure time was, the initial pH of wastewater was more favorable to photocatalytic degradation of the sugar wastewater for the Br-TiO2nanotube arrays, and compared to undoped TiO2nanotube arrays Br doped TiO2nanotube arrays had better photocatalytic properties.


2015 ◽  
Vol 802 ◽  
pp. 507-512 ◽  
Author(s):  
Chee Mei Lee ◽  
Puganeshwary Palaniandy ◽  
Nastaein Qamaruz Zaman ◽  
Mohd Nordin Adlan

Compound Parabolic Collecting Reactor (CPCR) was designed and used for the heterogeneous-photocatalytic treatment process. Sunray was act as an economically and ecologically sensible light source. The photocatalytic degradation of paracetamol in the synthetic wastewater by using titanium dioxide (TiO2) was investigated. The experimental results show that the paracetamol removal rates were very high and nearly equal (97.2% to 99.7%) at pH 4-7 and TiO2 concentration of 0.5-1 g/L. This implies that the photocatalytic degradation rate of paracetamol is not affected by pH range in this study as the electrostatic interaction between the TiO2 and paracetamol is not able to be developed unless a wider range of pH is set. Furthermore, the concentration of TiO2 of 0.5 g/L is too high to treat the concentration of 10 mg/L of paracetamol. Further research is needed in order to identify the optimum pH condition and a suitable correlation of concentration between TiO2 and paracetamol. Finally, the results proved that the heterogeneous-photocatalyst treatment method which associated with the application of CPCR and solar energy is able to eliminate the paracetamol from the synthetic wastewater.


2014 ◽  
Vol 894 ◽  
pp. 245-249 ◽  
Author(s):  
Arman Sikirman ◽  
Jagannathan Krishnan ◽  
Junaidah Jai ◽  
Senusi Faraziehan

Surface modification of the titanium dioxide by doping and co-doping with nitrogen and iron in order to make the photocatalyst active under visible light was investigated. Solgel method was adapted for the preparation of surface modified titanium dioxide, where tetra titanium isopropoxide, ammonium nitrate and ferric nitrate were used as precursors while maintaining the dopant concentration and calcination temperature at 0.75% and 600°C, respectively. The prepared photocatalyst samples were characterized by XRD, FE-SEM and FTIR in order to study their physical properties. The results from XRD confirmed that all prepared photocatalyst were of anatase phase. FE-SEM image analysis revealed the formation of fine particles and the FTIR analysis verified the presence of dopants. The effectivity of photocatalysts was tested by performing a standard batch photocatalytic degradation experiment with methylene blue as a model pollutant under visible light. The result showed that co-doped photocatalyst (0.75% N, 075% Fe-TiO2-600) yielded a maximum of 76% methylene blue degraded within three hours of irradiation time.


Author(s):  
Niyaz A. Mir ◽  
M.M. Haque ◽  
A. Khan ◽  
K. Umar ◽  
M. Muneer ◽  
...  

AbstractSemiconductor mediated hydrogen peroxide-assisted photocatalytic degradation of two selected pesticide compounds, chloramben (1) and cyanazine (2) has been investigated in aqueous suspensions under a variety of conditions. The degradation was studied by monitoring the depletion in total organic carbon (TOC) content and decrease in substrate concentration as a function of irradiation time. The degradation kinetics of pesticide compounds 1 and 2 were investigated under different conditions such as type of TiO


JETP Letters ◽  
2020 ◽  
Vol 112 (8) ◽  
pp. 471-477
Author(s):  
V. S. Krivobok ◽  
A. V. Kolobov ◽  
S. E. Dimitrieva ◽  
D. F. Aminev ◽  
S. I. Chentsov ◽  
...  

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 112
Author(s):  
Tamás Gyulavári ◽  
Kata Kovács ◽  
Klára Magyari ◽  
Kornélia Baán ◽  
Anna Szabó ◽  
...  

Carbon spheres were applied as templates to synthesize titanium dioxide hollow spheres. The templates were purified with either ethanol or acetone, and the effects of this treatment on the properties of the resulting titania were investigated. The photocatalytic activity of the catalysts was measured via the decomposition of phenol model pollutant under visible light irradiation. It was found that the solvent used for the purification of the carbon spheres had a surprisingly large impact on the crystal phase composition, morphology, and photocatalytic activity. Using ethanol resulted in a predominantly rutile phase titanium dioxide with regular morphology and higher photocatalytic activity (r0,phenol = 3.9 × 10−9 M∙s−1) than that containing mainly anatase phase prepared using acetone (r0,phenol = 1.2 × 10−9 M∙s−1), surpassing the photocatalytic activity of all investigated references. Based on infrared spectroscopy measurements, it was found that the carbon sphere templates had different surface properties that could result in the appearance of carbonate species in the titania lattice. The presence or absence of these species was found to be the determining factor in the development of the titania’s properties.


2021 ◽  
Vol 11 (2) ◽  
Author(s):  
S. Ismat Shah ◽  
Sawsan A. Mahmoud ◽  
Samar H. Bendary ◽  
Ahmed K. Aboulgheit ◽  
A. A. Salem ◽  
...  

AbstractPulsed laser deposition facilitates the epitaxial deposition and growth of TiO2 at low temperature on hot substrate. In this study, nanosized nitrogen-doped TiO2 thin films were deposited on fabricated alumina disc-shaped and glass substrates. Textural properties of the fabricated disc and alumina disc-supported TiO2 were investigated using N2 adsorption–desorption isotherms, field emission scanning electron microscopy (FESEM), X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy. FESEM showed the presence of single crystals of TiO2 on the alumina disc. FTIR showed the presence of octahedral TiO2 and different hydroxyl groups on the surface which is responsible for the photoactivity and also showed the functional groups adsorbed on the catalyst surface after the photocatalytic degradation. The concentration of 2-chlorophenol and the photo-redox intermediate products as a function of irradiation time was determined. The concentration of the produced chloride ion during the photocatalytic degradation was determined by an ion chromatography. The results showed that the photocatalytic activity of the catalyst decreased upon cycling. The obtained results were compared with nanostructured TiO2 supported on glass substrate. Higher efficiency of 100% degradation was achieved for TiO2/Al2O3 catalyst, whereas about 70% degradation of 2-CP was achieved using TiO2/glass. Different photointermediates of 2-CP degradation have been identified for each cycle. The difference of intermediates is supported by the adsorbed fragments on the catalyst surface.


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