Synthesis, Characterizations and Photocatalytic Activity of Mesoporous TiO2 Using Typha Latifolia as Template

2014 ◽  
Vol 1053 ◽  
pp. 495-502
Author(s):  
Ying Chun Miao ◽  
Guang Chen ◽  
Xiao Ling Xu
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Typha Latifolia ◽  
Mesoporous Titania ◽  
Residual Carbon ◽  
X Ray Diffraction ◽  
Silica Sample ◽  
Carbon Species ◽  
Titania Sample ◽  
Adsorption Desorption

Typha latifolia were successfully used as template to synthesize mesoporous titania and silica with efficient photocatalytic activity under solar and visible light. Both two titania and silica samples were characterized by a combination of various physicochemical techniques, such as, N2 adsorption/ desorption isotherm, diffuse reflectance UV-vis, and X-ray diffraction. It was found that both two synthesized samples exhibited similar morphologies to the original templates. The presence of the residual carbon species of mesoporous titania and silica strongly affects their photocatalytic activity. The photoactivity of P25 TiO2 could not almost exhibit while both mesoporous titania and silica samples exhibited varied photoactivities for dyes under visible light, due to the presence of the residual carbon species. Moreover, as a whole the titania sample enhanced the higher photocatalytic activity than the silica sample under both solar and visible light.

scholarly journals The Contrastive Research in the Photocatalytic Activity of BiOBr Synthesized by Different Reactants

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Wang Ling-Li ◽  
Ma Wan-Hong ◽  
Wang Shu-Lian ◽  
Zhang Yu ◽  
Jia Man-Ke ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Removal Rate ◽  
Active Species ◽  
X Ray Diffraction ◽  
Toc Removal ◽  
Transmission Electron ◽  
Uv Visible ◽  
Adsorption Desorption

BiOBr nanoplates, marked asα-BiOBr andβ-BiOBr, were synthesized via hydrothermal method using cetylpyridinium bromide (CPB) and NaBr as reactants, respectively. X-Ray Diffraction (XRD), transmission electron microscope (TEM), N2adsorption/desorption, UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), and cyclic voltammetry (CV) were employed to characterize the obtained BiOBr. The results showed thatα-BiOBr andβ-BiOBr can absorb visible light and both the band gaps of them were about 2.76 eV. Under visible light irradiation, the photodegradation of organic dye sulforhodamine (SRB) and salicylic acid (SA) usingα-BiOBr andβ-BiOBr as the catalysts was carried out. The reaction kinetic constants of the degradation of SRB byα-BiOBr andβ-BiOBr were 0.00602 min−1and 0.0047 min−1, respectively, which indicated that the photocatalytic activity ofα-BiOBr was higher than that ofβ-BiOBr. The UV-Vis DRS and total organic carbon (TOC) were also monitored, and the TOC removal rate ofα-BiOBr andβ-BiOBr was 86% and 48%, respectively. At the same time, hydrogen peroxide (H2O2) and active radicals were measured and analyzed, which showed that the main active species wasOH∙during the photocatalytic reaction.

Novel p–n junction UiO-66/BiOI photocatalysts with efficient visible-light-induced photocatalytic activity

2018 ◽  
Vol 77 (5) ◽  
pp. 1441-1448 ◽  
Author(s):  
Yuejin Li ◽  
Xili Shang ◽  
Changhai Li ◽  
Xiaoming Huang ◽  
Jingjing Zheng
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Salicylic Acid ◽  
Visible Light ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Uv Visible ◽  
Adsorption Desorption ◽  
Junction Structure ◽  
First Time

Abstract Novel visible-light-induced UiO-66/BiOI photocatalysts with a p–n junction structure have been prepared for the first time through a facile hydrothermal method. The prepared photocatalysts were characterized using the powder X-ray diffraction, high resolution transmission electron microscopy, scanning electron microscopy, UV–visible diffuse reflectance spectra, and N2 adsorption–desorption (Brunauer–Emmett–Teller) techniques respectively. The photodegradation performances of UiO-66/BiOI photocatalysts were evaluated by photodegrading salicylic acid under visible-light irradiation. The UiO-66/BiOI composites displayed much higher photocatalytic efficiencies than pure BiOI under visible light. When the content of UiO-66 was 5.2 wt%, the composite (UiO-66/BiOI-2) has the best photocatalytic activity. Most of the salicylic acid molecules can be degraded in 100 min. The degradation rate of UiO-66/BiOI-2 samples is higher than single BiOI and UiO-66. The enhanced photocatalytic performance of UiO-66/BiOI may be ascribed to the formation of p–n heterojunctions between BiOI and UiO-66, which facilitates the transfer and separation of the photogenerated charge carriers. After recycling of the photocatalyst for five times for the photodegradation of salicylic acid, more than 85% of salicylic acid could still be degraded in the fifth cycle, implying that the as-prepared photocatalysts are highly stable.

scholarly journals Visible Light-Driven Photocatalytic Activity of Magnetic Recoverable Ternary ZnFe2O4/rGO/g-C3N4 Nanocomposites

2020 ◽  
Vol 67 (4) ◽  
pp. 1082-1091
Author(s):  
Martin Tsvetkov ◽  
Elzhana Encheva ◽  
Albin Pintar ◽  
Maria Milanova
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Weight Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Visible Light Driven ◽  
Physicochemical Methods ◽  
Green Model ◽  
Adsorption Desorption

ZnFe2O4/rGO/g-C3N4 ternary nanocomposite photocatalysts with different ZnFe2O4/g-C3N4 weight ratio (0.5, 0.75, 1) were prepared by a stepwise solvothermal method using ethylene glycol as the solvent. Physicochemical methods such as X-ray diffraction, UV-Vis diffuse reflectance spectroscopy and photoluminescence spectroscopy were applied in order to characterize the composites. The formation of a meso-/macroporous structure with specific surface area between 67 and 77 m2 g–1 was confirmed by N2 adsorption/desorption. The bandgap of the composites was found to be lower (2.30 eV) than that of g-C3N4 (2.7 eV). In contrast to pure g-C3N4, the composites showed no fluorescence, i.e. no recombination of e–/h+ took place. All samples, including pure g-C3N4 and ZnFe2O4, were tested for adsorption and photocatalytic degradation of aqueous malachite green model solutions (10–5 M) under visible light irradiation (λ > 400 nm). The results show that the prepared nanocomposites have higher absorption and photocatalytic activity than the pristine g-C3N4 and ZnFe2O4 and can be successfully used for water purification from organic azo-dyes.

PEG-Assisted Hydrothermal Synthesis and Photocatalytic Activity of Bi2Fe4O9 Crystallites

2011 ◽  
Vol 1292 ◽  
Author(s):  
Dengrong Cai ◽  
Jianmin Li ◽  
Shundong Bu ◽  
Shengwen Yu ◽  
Dengren Jin ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectrum ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Peg 400 ◽  
Transmission Electron ◽  
Light Region ◽  
Facile Hydrothermal Route ◽  
Degradation Ratio

ABSTRACTA facile hydrothermal route assisted by polyethylene glycol (PEG) 400 was utilized to synthesize single-phase Bi2Fe4O9 crystallites. X-ray diffraction results showed the products with PEG 400 of 30 g/L exhibited a preferred growth along the (001) plane. Transmission electron microscopy indicated that the morphology of the as-prepared Bi2Fe4O9 crystallites with PEG 400 were plake-like and rod-like. Strong absorption in visible-light region of the products was characterized by UV-vis diffuse reflectance spectrum (UV-DRS). The photocatalytic activity of Bi2Fe4O9 crystallites was evaluated on degradation of methyl orange (MO) under visible light irradiation. For 3 h irradiation, the degradation ratio was increased to 93% with the aid of a small amount of H2O2. The analysis of FT-IR spectra proved that the Bi2Fe4O9 catalysts were remained stable after the photocalytic reactions.

Preparation of Visible-Light-Responsive TiO2-xNx Photocatalyst by a Very Simple Method

2011 ◽  
Vol 383-390 ◽  
pp. 3188-3191
Author(s):  
Han Jie Huang ◽  
Wen Long She ◽  
Ling Wen Yang ◽  
Hai Peng Huang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflection ◽  
Ammonia Solution ◽  
Reflection Spectra ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
Light Excitation

A visible-light-responsive TiO2-xNx photocatalyst was prepared by a very simple method. Ammonia solution was used as nitrogen resource in this paper. The TiO2-xNx photocatalyst was characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), UV-Vis diffuse reflection spectra (DRS), and X-ray photoelectron spectroscopy (XPS). The ethylene was selected as a target pollutant under visible light excitation to evaluate the activity of this photocatalyst. The new prepared TiO2-xNx photocatalyst with strong photocatalytic activity under visible light irradiation was demonstrated in the experiment.

Few-Layered MoS2 Nanostructures for Highly Efficient Visible Light Photocatalysis

NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Electrochemical Impedance Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Hole Pair

Few-layered MoS2 nanostructures were successfully synthesized by a simple hydrothermal method without the addition of any catalysts or surfactants. Their morphology, structure and photocatalytic activity were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, electrochemical impedance spectra and UV-Vis absorption spectroscopy, respectively. These results show that the MoS2 nanostructures synthesized at 180[Formula: see text]C exhibit an optimal visible light photocatalytic activity (99%) in the degradation of Rhodamine B owing to the relatively easier adsorption of pollutants, higher visible light absorption and lower electron–hole pair recombination.

Enhanced visible-active photocatalytic behaviors observed in Mn-doped BiFeO3

2018 ◽  
Vol 32 (17) ◽  
pp. 1850185 ◽  
Author(s):  
Yun-Hui Si ◽  
Yu Xia ◽  
Ya-Yun Li ◽  
Shao-Ke Shang ◽  
Xin-Bo Xiong ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
X Ray ◽  
Mn Doped ◽  
Hole Recombination ◽  
Narrow Band Gap Semiconductors

A series of BiFeO3 and BiFe[Formula: see text]Mn[Formula: see text]O3 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by a hydrothermal method. The samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy (EDS) and UV–Vis diffuse reflectance spectroscopy, and their photocatalytic activity was studied by photocatalytic degradation of methylene blue in aqueous solution under visible light irradiation. The band gap of BiFeO3 was significantly decreased from 2.26 eV to 1.90 eV with the doping of Mn. Furthermore, the 6% Mn-doped BiFeO3 photocatalyst exhibited the best activity with a degradation rate of 94% after irradiation for 100 min. The enhanced photocatalytic activity with Mn doping could be attributed to the enhanced optical absorption, increment of surface reactive sites and reduction of electron–hole recombination. Our results may be conducive to design more efficient photocatalysts responsive to visible light among narrow band gap semiconductors.

W-Doped TiO2 Preparation and Photocatalytic Degradation of Guaiacol

2014 ◽  
Vol 513-517 ◽  
pp. 33-36 ◽  
Author(s):  
Zi Chang Xie ◽  
Ying Wang ◽  
Peng Wang ◽  
Lei Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Degradation Rate ◽  
Amorphous State ◽  
X Ray Diffraction ◽  
Model Compounds ◽  
Plant Fibers ◽  
X Ray ◽  
Crystallite Structure

In this paper, W-doped TiO2 (W-TiO2) powder was prepared in hydrothermal method by mixing TiO2 and ammonium metatungstate. The catalysts were characterized by X-ray diffraction and ultraviolet spectrophotometer. The results displayed that W-TiO2 showed an anatase crystallite structure with 2 % W content. W-element in W-TiO2 was amorphous state. The guaiacol was degraded with the W-TiO2 in the visible light. It was a model compounds of lignin existed in the plant fibers. The degradation rate of guaiacol was increased with the photocatalytic time, as high as 88.21 % after 360 min irradiation. It was concluded that the W-TiO2 had an obvious photocatalytic activity under visible light. It can be used in the photocatalytic degradation of lignin.

Preparation, Characterization and Photocatalytic Activity of F, Fe-Codoped Nano-TiO2

2013 ◽  
Vol 448-453 ◽  
pp. 169-173
Author(s):  
Chun Yan Yan ◽  
Wen Tao Yi
Keyword(s):  
Photocatalytic Activity ◽  
Diffuse Reflectance Spectroscopy ◽  
Uv Light ◽  
Hydrothermal Process ◽  
Neutral Red ◽  
Reaction Model ◽  
X Ray Diffraction ◽  
Pseudo First Order Reaction ◽  
Adsorption Desorption ◽  
Desorption Method

Pure and F, Fe-codoped TiO2 were prepared by sol-hydrothermal process, in which titanium (IV) n-butoxide, Fe (NO3)2·6H2O and NH4F were used as precursors. And the samples were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), and N2 adsorption-desorption method. The results showed that the F, Fe-codoped samples were principally single-phase anatase structures, and the particles possessed higher BET area than that of pure TiO2. The photocatalytic activity and reusability of the catalysts under UV light (365nm) was investigated with neutral red as the model compound. The results showed that F (2.0%), Fe (4.0%) codoped TiO2 had the highest photocatalytic activity among all as-prepared samples. The kinetic study showed that this photocatalytic process coincided with the Langmuir-Hinshelwood (L-H) pseudo first order reaction model.

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