Low-temperature hydrothermal synthesis of S-doped TiO2 with visible light photocatalytic activity

Ho, Wingkei; Yu, Jimmy C.; Lee, Shuncheng

doi:10.1016/j.jssc.2006.01.009

Cited by 254 publications

(146 citation statements)

References 54 publications

Supporting

Mentioning

137

Contrasting

Unclassified

Order By: Relevance

“…Other factors are also important such as the crystallinity and particle size of the material and the ability of the material to retard the electron-hole recombination process [50][51][52][53][58][59][60].…”

Section: Resultsmentioning

confidence: 99%

Carbon-Doped TiO₂ and Carbon, Tungsten-Codoped TiO₂ through Sol–Gel Processes in the Presence of Melamine Borate: Reflections through Photocatalysis

Neville¹,

Mattle

Loughrey³

et al. 2012

J. Phys. Chem. C

118

View full text Add to dashboard Cite

A series of C-doped, W-doped, and C,W-codoped TiO2 samples have been prepared using modified sol–gel techniques. Reproducible inexpensive C-doping arises from the presence of melamine borate in a sol–gel mixture, whereas W-doping is from the addition of tungstic acid to the sol. The materials have been characterized using elemental analysis, N2 physisorption (BET), thermogravimetric analysis, X-ray diffraction, Raman, X-ray photoelectron, UV–vis spectroscopies, and photocatalytic activity measurements. Doping C and W independently results in an increased absorbance in the visible region of the spectrum with a synergistic effect in increased absorbance when both elements are codoped. The increased visible-light absorbance of the W-doped or codoped materials is not reflected in photocatalytic activity. Visible-light-induced photocatalytic activity of C-doped material was superior to that of an undoped catalyst, paving the way for its application under only visible-light irradiation conditions. A significant fraction of the spectral red shift commonly observed with doped catalysts might be due to the formation of color centers as a result of defects associated with oxygen vacancies, and bandgap-related narrowing or intragap localization of dopant levels are not the only factors responsible for enhanced visible-light absorption in doped photocatalysts. Furthermore, bandgap narrowing through increases in the energy of the valence band may actually decrease photo-oxidation activity through a curtailment of one route of oxidation.

show abstract

Section: Resultsmentioning

confidence: 99%

Carbon-Doped TiO₂ and Carbon, Tungsten-Codoped TiO₂ through Sol–Gel Processes in the Presence of Melamine Borate: Reflections through Photocatalysis

Neville¹,

Mattle

Loughrey³

et al. 2012

J. Phys. Chem. C

118

View full text Add to dashboard Cite

show abstract

“…Doping sulfur atoms into the TiO 2 lattice improves the photocatalytic efficiency under visible light irradiation [72]. When fine crystalline S-doped TiO 2 was synthesized in the study of Ho et al [72] through a simple hydrothermal method, the optical absorption of S-doped TiO 2 in the visible light region increased in tandem with the increase in the S content.…”

Section: Effect Of Nonmetal Dopingmentioning

confidence: 99%

An Overview on the Photocatalytic Activity of Nano-Doped-TiO2 in the Degradation of Organic Pollutants

Tan

Wong

Mohamed

2011

ISRN Materials Science

112

View full text Add to dashboard Cite

This paper aims to review and summarize the recent works on the photocatalytic degradation of various organic pollutants in the presence of nano-doped-TiO 2 photocatalysts. In this regard, three main aspects are examined: (a) the presence of various dopants (metal dopants, nonmetal dopants, halogen dopants, metalloid dopants, and codopants) in the formation of nano-doped-TiO 2 photocatalysts, (b) the effect of the presence of dopants on the photocatalytic degradation of organic pollutants, and (c) the effects of various operating parameters on the photocatalytic degradation of organic pollutants in the presence of nano-doped-TiO 2 photocatalysts. Reports resulted suggest that the formation of a high percentage of the anatase phase, small crystallite size, and high specific surface area of the nano-doped-TiO 2 photocatalysts depends on the presence of various dopants in the photocatalysts. The majority of the dopants have the potential to improve the photocatalytic efficiency of nano-doped-TiO 2 in the degradation of organic pollutants. The photocatalytic degradation of organic compounds depends on the calcination temperature of the prepared doped TiO 2 , initial reactant concentration, dosage of doped TiO 2 , and dopant doping concentration.

show abstract

“…20,21 Ho et al investigated the antibacterial effect of S-doped titania prepared using thiourea and this study revealed that S-doped titania was effective in killing Micrococcus lylae, a gram positive bacterium. 20,21 Recent literature reports indicate that sulphur could either add to the TiO 2 matrix as a cation or an anion depending upon the sulphur source employed. [22][23][24][25][26][27] Umebayashi et al…”

Section: Introductionmentioning

confidence: 99%

Improved High-Temperature Stability and Sun-Light-Driven Photocatalytic Activity of Sulfur-Doped Anatase TiO₂

et al. 2008

View full text Add to dashboard Cite

Of the various forms of titania (anatase, rutile and brookite) anatase is found to be the best photocatalyst. Without any chemical additives, the anatase to rutile transformation in pure synthetic titania usually occurs at a temperature range of 600 to 700 °C. High temperature (≥800 °C) stable photoactive anatase titania is required for antibacterial, application in building materials. A simple methodology to extend the anatase phase stability by modifying the titanium isopropoxide precursor by sulphur modification using sulphuric acid is presented. Chemical synthesis by sol-gel method involved the reaction of titanium tetraisopropoxide (TTIP) with sulphuric acid (H 2 SO 4 ), followed by hydrolysis and condensation. The xerogel formed after drying was subjected to further calcination at different temperatures. Various TTIP:H 2 SO 4 molar ratios such as, 1:1, 1:2, 1:4, 1:8 and 1:16 were prepared and these samples characterized by XRD, DSC, Raman spectroscopy, XPS and BET surface area analysis.Sulphur modified samples showed extended anatase phase stability up to 900 ºC, while the control sample prepared under similar conditions completely converted to rutile phase at 800 ºC. Stoichiometric modification up to 1:4 TTIP: H 2 SO 4 composition (TS4) was found to be most effective in extending the anatase to rutile phase transformation by 200 °C compared to the control sample and it shows 100 % anatase at 800 °C and 20 % anatase at 900 ºC. Samples of 1:4 TTIP:H 2 SO 4 composition calcined at various temperatures such as 700, 800, 850 and 900 ºC showed significantly higher photocatalytic activity compared to the control sample. The 1:4 TTIP:H 2 SO 4 composition calcined at 850 ºC showed the highest photoactivity and it decolorized the rhodamine 6G dye within 12 minutes (rate constant 0.27 min -1 ) whereas the control sample prepared under identical condition decolorized the dye after 80 minutes (rate constant 0.02 min -1 ). It was also observed that the optimal size for highly photoactive anatase crystal is ca. 15 nm. XPS studies indicated that the retention of the anatase phase at high temperatures is due to the existence of small amounts of sulphur up to 900 °C.

show abstract

Low-temperature hydrothermal synthesis of S-doped TiO2 with visible light photocatalytic activity

Cited by 254 publications

References 54 publications

Carbon-Doped TiO₂ and Carbon, Tungsten-Codoped TiO₂ through Sol–Gel Processes in the Presence of Melamine Borate: Reflections through Photocatalysis

Carbon-Doped TiO₂ and Carbon, Tungsten-Codoped TiO₂ through Sol–Gel Processes in the Presence of Melamine Borate: Reflections through Photocatalysis

An Overview on the Photocatalytic Activity of Nano-Doped-TiO2 in the Degradation of Organic Pollutants

Improved High-Temperature Stability and Sun-Light-Driven Photocatalytic Activity of Sulfur-Doped Anatase TiO₂

Contact Info

Product

Resources

About

Low-temperature hydrothermal synthesis of S-doped TiO2 with visible light photocatalytic activity

Cited by 254 publications

References 54 publications

Carbon-Doped TiO2 and Carbon, Tungsten-Codoped TiO2 through Sol–Gel Processes in the Presence of Melamine Borate: Reflections through Photocatalysis

Carbon-Doped TiO2 and Carbon, Tungsten-Codoped TiO2 through Sol–Gel Processes in the Presence of Melamine Borate: Reflections through Photocatalysis

An Overview on the Photocatalytic Activity of Nano-Doped-TiO2 in the Degradation of Organic Pollutants

Improved High-Temperature Stability and Sun-Light-Driven Photocatalytic Activity of Sulfur-Doped Anatase TiO2

Contact Info

Product

Resources

About

Carbon-Doped TiO₂ and Carbon, Tungsten-Codoped TiO₂ through Sol–Gel Processes in the Presence of Melamine Borate: Reflections through Photocatalysis

Carbon-Doped TiO₂ and Carbon, Tungsten-Codoped TiO₂ through Sol–Gel Processes in the Presence of Melamine Borate: Reflections through Photocatalysis

Improved High-Temperature Stability and Sun-Light-Driven Photocatalytic Activity of Sulfur-Doped Anatase TiO₂