Preparation of visible light active S-doped TiO2 photocatalysts and their photocatalytic activities

2004 ◽  
Vol 49 (4) ◽  
pp. 159-163 ◽  
Author(s):  
T. Ohno

Although titanium dioxide photocatalysts having an anatase phase are a promising substrate for photodegradation of pollutants in water and air, their photocatalytic activities show only under UV light. To utilize solar light which has a large amount of visible light, the development of the photocatalysts whose activities show under visible light is one of the most important strategies. We have succeeded in synthesizing chemically modified titanium dioxide photocatalysts in which S (S4+) substitutes for some of the lattice titanium atoms. They show strong absorption for visible light and high activities for degradation of 2-propanol in aqueous solution and partial oxidation of adamantane in acetonitrile under irradiation at wavelengths longer than 440 nm. The oxidation state of the S atoms incorporated into the TiO2 particles is determined to be mainly S4+ from XPS spectra.

2020 ◽  
Vol 1 (1) ◽  
pp. 30-36
Author(s):  
Shubha Jayachamarajapura Pranesh ◽  
Diwya Lanka

Background: Textile industries discharge harmful synthetic dyes to nearby water sources. These colour effluents should be treated before discharge to reduce the toxicity caused by synthetic colours. Objective: To synthesize visible light active superstructures to reduce water pollution caused by textile industries. Methods: We have successfully synthesized ZnO/Dy/NiO hybrid nanocomposites using waste curd as fuel by a simple combustion method. The obtained material was able to reduce recombination and enhanced the photocatalytic degradation of organic pollutants. The as-synthesized material was characterized by XRD, absorption spectroscopy, FESEM, EDAX, etc. The obtained hybrid nanostructure was used as a photocatalyst for the degradation of methylene blue under sunlight, UV light as well as in dark. Comparative experiments were carried out with a variation of catalytic load, pH, dye concentrations, etc. for a better understanding of the performance of the catalyst at various conditions. Results and Conclusion: The ternary compound shows wide range of absorption by expanding absorption band both in UV and visible regions. ZnO/Dy/NiO hybrid nanocomposites performed well and showed uniqueness in the activity uder visible light.


RSC Advances ◽  
2017 ◽  
Vol 7 (76) ◽  
pp. 48083-48094 ◽  
Author(s):  
Sunderishwary S. Muniandy ◽  
Noor Haida Mohd Kaus ◽  
Zhong-Tao Jiang ◽  
Mohammednoor Altarawneh ◽  
Hooi Ling Lee

Mesoporous anatase TiO2 nanoparticles are produced by employing a facile green chemistry approach at low temperature with soluble starch as the template in this work. The obtained TiO2 photocatalyst is visible-light active with good photocatalytic activities.


2018 ◽  
Vol 765 ◽  
pp. 551-559 ◽  
Author(s):  
Yanjie Wang ◽  
Ayyakannu Sundaram Ganeshraja ◽  
Changzi Jin ◽  
Kaixin Zhu ◽  
Junhu Wang

2018 ◽  
Vol 85 (13) ◽  
pp. 1203-1217 ◽  
Author(s):  
Ketsuda Kongsawatvoragul ◽  
Saran Kalasina ◽  
Montakan Suksomboon ◽  
Nutthaphon Phattharasupakun ◽  
Juthaporn Wutthiprom ◽  
...  

2010 ◽  
Vol 24 (15n16) ◽  
pp. 3242-3247 ◽  
Author(s):  
MASAHIRO KATOH ◽  
AKIHIRO IMAYAMA ◽  
NARISUKE MORI ◽  
TOSHIHIDE HORIKAWA ◽  
TAHEI TOMIDA

Introducing different atoms into TiO 2 crystal lattice is a famous method to improve photocatalytic activity of TiO 2 under visible-light irradiation. In this paper, Nitrogen ( N ) and fluorine ( F ) co -doped TiO 2 powders were prepared by mixing TiCl 3 solutions with ammonium fluoride ( NH 4 F ). In preparation, we used NH 3- H 2 O solution for adjustment of pH values (pH 2, 7, and 9) of mixed solution. X-ray diffraction (XRD) indicated N , F - TiO 2 powders prepared at pH7 and pH9 contained only anatase phase, but the powders prepared at pH2 contained both anatase and rutile phase. The result of XRD also indicated N , F - TiO 2 powders prepared at pH7 had the smallest crystallite size. We measured photocatalytic activity of prepared N , F - TiO 2 powders by the decomposition of methylene blue. N , F - TiO 2 powder prepared at pH7 and pH9 showed same high photocatalytic activity under ultraviolet light irradiation (peak wave length = 352 nm). Furthermore, under green light LED irradiation (wave length = 525 nm), a sample prepared at pH7 decomposed methylene blue more quickly than any other samples. As the result, N , F - TiO 2 prepared at pH7 had the best catalytic activity under both UV-light and visible light in the all of N , F - TiO 2 prepared and reference TiO 2 photocatalyst (ST-01 produced by Ishihara Co. Ltd).


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.


2014 ◽  
Vol 43 (33) ◽  
pp. 12480 ◽  
Author(s):  
Michał Pacia ◽  
Piotr Warszyński ◽  
Wojciech Macyk

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