Solar Photocatalytic Decontamination of Phenol Using Pyrolytic TiO2 Films Deposited Inside Glass Tubing

2006 ◽  
Vol 129 (1) ◽  
pp. 94-99 ◽  
Author(s):  
José Diaz ◽  
Juan Rodríguez ◽  
Silvia Ponce ◽  
José Solís ◽  
Walter Estrada

Solar photocatalytic degradation of phenol was performed using TiO2 films deposited inside glass tubing by a spray-gel technique. Photocatalytic phenol degradation experiments were performed using either solar radiation or a 300W lamp simulating the UVA solar radiation component. In order to concentrate the radiation a reflective surface was placed in the rear part of the tube. The obtained TiO2 films were amorphous, but after annealing at 450°C for 1h, the films crystallized to the anatase structure and presented photocatalytic activity. The films’ morphology, observed by scanning electron microscopy, presented a uniform film and agglomerates of TiO2. The size of the agglomerates increases as Ti isopropoxide/ethanol molar ratio of the starting solution increases. The concentration of the precursor solution and the film thickness of TiO2 was optimized for phenol degradation. The TiO2 film obtained with a Ti-isopropoxide/ethanol molar ratio of 0.0259 and a film thickness between 1.2to2.4μm were shown to yield the highest phenol degradation.

2012 ◽  
Vol 629 ◽  
pp. 332-338 ◽  
Author(s):  
Zhi Hua Tian ◽  
Jian Xi Yao ◽  
Mi Na Guli

TiO2 films with three-dimensional web-like structure have been prepared by the photo polymerization-induced phase separation method (PIPS). Scanning electron microscopy and X-ray diffraction were used to characterize the as-prepared TiO2 films. The results showed that the film texture could be tuned by changing the composition of the precursor solution. The TiO2 film with web-like structure exhibited high photocatalytic activity for the degradation of methylene blue (MB) dye. The as-prepared films were used as the photo-anodes in dye-sensitized solar cells (DSCs). The photoelectric conversion efficiency of the DSCs was significantly enhanced by changing the POGTA/TTB in the precursor solution. Because of the increased dye adsorption active sites and efficient electron transport in the TiO2 anode film, a photoelectric conversion efficiency of 3.015% was obtained.


2020 ◽  
Vol 58 (4) ◽  
pp. 263-271
Author(s):  
Yaejin Hong ◽  
Seung-Hwan Jeon ◽  
Hyukhyun Ryu ◽  
Won-Jae Lee

In this study, Fe2O3 photoelectrode thin films were grown on fluorine-doped tin oxide substrates at various temperatures ranging from 145 to 220 oC using modified chemical bath deposition. The morphological, structural, electrical, and photoelectrochemical properties of the resulting Fe2O3 photoelectrode were analyzed using field emission scanning electron microscopy, X-ray diffraction, electrochemical impedance spectroscopy, and a three-electrode potentiostat/galvanostat, respectively. Growth temperature and hydrochloric acid etching both affected the growth of the Fe2O3 photoelectrode, with Fe2O3 thin film thickness first increasing and then decreasing as growth temperature increased. The pH value of the precursor solution varied according to growth temperature, which in turn affected film thickness. The highest photocurrent density (0.53 mA/cm2 at 0.5 V vs. saturated calomel electrode) was obtained from the Fe2O3 photoelectrode grown at 190 oC, which yielded the thickest thin film, smallest full width at half maximum and largest grain size for the (104) and (110) plane, and highest flat-band potential value. Based on these findings, the photoelectrochemical properties of Fe2O3 photoelectrodes grown at various temperatures are strongly affected by their morphological, structural, and electrical properties.


2018 ◽  
Vol 6 (6) ◽  
pp. 1573-1578 ◽  
Author(s):  
Fangming Jin ◽  
Bo Zhao ◽  
Bei Chu ◽  
Haifeng Zhao ◽  
Zisheng Su ◽  
...  

Perovskite LEDs based on CsPbBr3 powder led to 48 and 12 times enhancement in peak brightness, compared to the different molar ratio CsBr/PbBr2 precursor solution devices, and reached 4590 cd m−2.


2021 ◽  
Vol 10 (3) ◽  
pp. xx-xx
Author(s):  
Thao Pham Thi Minh ◽  
Huong Do Thi ◽  
Hai Le Thi

The ZnO-ZrO2 nanocompsite materials in the molar ratio (1:0; 1:1; 1:2; 2:1; 3:4; 4:3; 0:1) were prepared by a two-stage precipitation method with ultrasonic vibrations. The obtained ZnO-ZrO2 materials were characterized by XRD, SEM, UV-vis. XRD data identified phase of the ZnO and phase of ZrO2 in all obtained samples. The average crystallite size of the samples was between 18 to 30 nm. As UV-Vis spectra, the band gap of ZnO-ZrO2 composite (ZZ34R) is 3,06eV. The photocatalytic reactions confirmed that the nanocomposite sample showed higher photocatalytic activity than the pure oxides samples for the degradation phenol under 100W incandescent lamp. Among the prepared samples, the best sample for photocatalytic degration of phenol is the ZZ34R which the molar ratio ZnO:ZrO2 = 3:4 with 23% remaining phenol content after 300 minutes. The photodegradation phenol of sample with ultrasonic vibrations is higher than the sample without ultrasonic vibrations. This indicates that the materials are capable of treating phenol in wastewater.


2011 ◽  
Vol 130 (1-2) ◽  
pp. 264-269 ◽  
Author(s):  
Go Kawamura ◽  
Yuuki Tsurumi ◽  
Hiroyuki Muto ◽  
Mototsugu Sakai ◽  
Mitsuteru Inoue ◽  
...  
Keyword(s):  
Sol Gel ◽  

2015 ◽  
Vol 776 ◽  
pp. 271-276 ◽  
Author(s):  
Nor Hafizah ◽  
Iis Sopyan

Photocatalysis has been proven effective in controlling various environmental problems originated by pollutions both in liquid and gaseous phases. Titanium dioxide (TiO2) is well known the most practical photocatalyst as it has high photocatalytic efficiency, low band gap energy, and no toxicity. Various chemical methods have been tried to produce TiO2 photocatalyst powder with high activity. In this study, sol-gel method has been employed to produce nanosized TiO2 photocatalyst particles and its physical properties and photocatalytic activity in phenol degradation test were compared with the commercial TiO2 powder, Degussa P25. The synthesis process was carried out through hydrolysis of titanium tetraisopropoxide (TPT) and methanol where the molar ratio of water to TPT was monitored to control the hydrolysis rate. From X-Ray Diffraction (XRD) analysis, the sol-gel TiO2 powder obtained was fully in anatase structure with high crystallinity. Scanning Electron Microscope (SEM) measurement showed that the powder was in nanoto sub-micron size, spherical in shape, and tightly agglomerated. Thermal analysis confirmed that sol-gel derived amorphous TiO2 powder transformed to anatase phase after 400°C calcination. The test on photocatalytic performance conducted using aqueous solution of phenol as the representative of water pollutant examined in this study showed that the sol-gel TiO2 powder is more efficient in degrading phenol compared to one of the most active photocatalysts commercially available, Degussa P25.


1995 ◽  
Vol 10 (3) ◽  
pp. 521-529 ◽  
Author(s):  
Wojciech Suchanek ◽  
Hiroyuki Suda ◽  
Masatomo Yashima ◽  
Masato Kakihana ◽  
Masahiro Yoshimura

Hydroxyapatite whiskers have been prepared by the hydrothermal method. The crystals had diameter, length, and aspect ratio in the range of 1–10 μm, 30–50 μm, and 5–20, respectively. Their Ca/P molar ratio varied from 1.59 to 1.62. The morphology of the crystals can easily be controlled by the concentrations of species in the starting solution, while the Ca/P ratio is almost independent of them. Through the reaction with calcite powder at 600 °C, the Ca/P ratio of the whiskers has been improved even to the stoichiometric value of 1.67. Taking into account morphology and chemical composition of the HAp whiskers, they should not be health hazardous and may find applications as substitutes for asbestos and other fibrous materials which presently have restricted use because of their carcinogenic natures.


1993 ◽  
Vol 234 (1-2) ◽  
pp. 561-565 ◽  
Author(s):  
M. Gartner ◽  
C. Parlog ◽  
P. Osiceanu
Keyword(s):  
Sol Gel ◽  

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