Photocatalytic Degradation of Methyl Orange by a New Photoctalyst Multi-Walled Carbon Nanotues (MWCNTs)/TiO2/CdS Nanocomposite

2012 ◽  
Vol 184-185 ◽  
pp. 1084-1089
Author(s):  
Ou Yang Ke ◽  
Xie Shan ◽  
Xiao Ou Ma ◽  
Meng Li ◽  
Qiu Lian Feng
Keyword(s):  
Methyl Orange ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Sol Gel ◽  
Oxidative Degradation ◽  
Pure Tio2 ◽  
First Order Kinetics ◽  
Composite Photocatalysts ◽  
Sol Gel Process ◽  
Light Absorbance

Composite photocatalysts using TiO2 coated by Multi-walled carbon nanotues(MWCNTs) and CdS were prepared by sol-gel process. The purpose of adding MWCNTs and CdS was extending the light absorbance range of pure TiO2 to visible light. Methyl orange (MO) was chosen as an object. The degradation of MO by MWCNTs/TiO2/CdS composite photocatalysts under visible light irradiation was studied. The results showed that the presence of MWCNTs and CdS can enhance the photoefficiency of TiO2 greatly. In addition, The photocatalyst was used for five cycles with photocatalytic degradation efficiency still higher than 96%. The photocatalytic degradation of MO followed a first-order kinetics according to the Langmuir-Hinshelwood model. A possible decomposing mechanism for the photocatalytic oxidative degradation was also discussed. The results of the study showed the potential use of MWCNTs/TiO2/CdS composite in degradation of toxic organic pollutants.

BiOCl/TiO2 composite photocatalysts synthesized by the sol–gel method for enhanced visible-light catalytic activity toward methyl orange

2020 ◽  
Vol 35 (22) ◽  
pp. 3067-3078
Author(s):  
Xiaofei Qu ◽  
Xiaohui Zhao ◽  
Meihua Liu ◽  
Zhaoqun Gao ◽  
Donglin Yang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Composite Photocatalysts

Abstract

Visible-Light Driven LaNiO3 Nanosized Photocatalysts Prepared by a Sol-Gel Process

2011 ◽  
Vol 279 ◽  
pp. 83-87 ◽  
Author(s):  
Pei Song Tang ◽  
He Sun ◽  
Feng Cao ◽  
Jin Tian Yang ◽  
Sheng Liang Ni ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Light Absorption ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
High Photocatalytic Activity ◽  
Visible Light Absorption ◽  
Average Grain Size ◽  
Sol Gel Process

The LaNiO3 nanoparticles were prepared by a sol-gel process. The LaNiO3 nanoparticles were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis diffuse reflectance spectroscopy (DRS). XRD and SEM demonstrate the successful synthesis of single phase perovskite LaNiO3 and an average grain size of 80 nm in diameter. It was found that the as-prepared LaNiO3 shows strong visible-light absorption with absorption onset of 545 nm, indicating a narrow optical band gap of 2.28 eV. Consequently, LaNiO3 nanoparticles show high visible-light photocatalytic activity for decomposition of methyl orange in comparison with the commercial Degussa P25. The photocatalytic experiment shows the high photocatalytic activity for the decomposition of methyl orange under visible-light irradiation, which is attributed to the strong visible-light absorption.

Preparation and Properties of Composite TiO2-HZSM-5 Used for Photocatalytic Degradation of Methyl Orange

2010 ◽  
Vol 26-28 ◽  
pp. 281-284
Author(s):  
Wen Jie Zhang ◽  
Yang Yu
Keyword(s):  
Methyl Orange ◽  
Photocatalytic Degradation ◽  
Pure Tio2 ◽  
Dispersion Method ◽  
Removal Rates ◽  
Tio2 Particles ◽  
Composite Photocatalysts ◽  
Photocatalytic Activities ◽  
Degradation Activity ◽  
Degradation Of Methyl Orange

Photocatalytic activities of TiO2-HZSM-5 composite photocatalysts prepared by solid-state dispersion method were investigated. TiO2 particles were well distributed on the surface of HZSM-5. Methyl orange removal rates increased with decreasing TiO2:HZSM-5 ratio from 10:1 to 1:50 in TiO2-HZSM-5 composites. Adsorption of methyl orange increased constantly with increasing amount of HZSM-5. Photocatalytic degradation activity was also noticeably enhanced up to 56% when using TiO2-HZSM-5 composite, resulting in 13% more removal compared with using pure TiO2. Composite photocatalysts calcinated at temperatures from 400 oC to 600 oC exhibited enhanced methyl orange removal abilities, and the optimum calcination temperature was 450 oC. After 70 min of irradiation, methyl orange removal rates were 99.1% and 86.5% when TiO2 concentrations of TiO2-HZSM-5 composite were 40 mg/l and 20 mg/l, respectively.

REE Lanthanum Doping Influence on the Photocatalysis Properties of Titanium Dioxide

2012 ◽  
Vol 550-553 ◽  
pp. 388-391
Author(s):  
Xing Jin ◽  
Jin Lan Lian ◽  
Yu Qiao
Keyword(s):  
Titanium Dioxide ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Sol Gel ◽  
Methyl Orange Solution ◽  
Lanthanum Doping ◽  
Light Area ◽  
Orange Solution

Lanthanum doping TiO2 were prepared by sol-gel method, an the photocatalytic degradation experiments were performed by using methyl orange solution as a target degradant. The results indicated that Suitable doping quantity of lanthanum can improve the photocatalytic activity of nanometer TiO2 powders. On the basis of 50 mL methyl orange solution what concentration is 20 mg/L, photocatalytic activity is the best when doping quantity of lanthanum were 1.0 wt %. Through the relatively experiments by using sunshine and ultraviolet as light source, the results indicated that the La3+ doping broaden the scope of visible light area what TiO2 response to.

Enhanced catalytic performance of β-FeOOH by coupling with single-walled carbon nanotubes in a visible-light-Fenton-like process

2018 ◽  
Vol 25 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Di Fang ◽  
Yaqun Yu ◽  
Zhihui Xu ◽  
Jiangru Liang ◽  
Lixiang Zhou
Keyword(s):  
Carbon Nanotubes ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Catalytic Mechanism ◽  
Oxidative Degradation ◽  
Catalytic Performance ◽  
Composite Photocatalysts ◽  
Walled Carbon Nanotubes ◽  
Degradation Of Methyl Orange

AbstractCarbon nanotubes/akaganeite composite photocatalysts (CNTs/β-FeOOH) with different weight addition ratios of CNTs have been synthesized by a very simple hydrothermal method. X-ray diffraction, Fourier transform infrared spectrum, UV-vis diffuse reflectance spectra, scanning electron microscopy, and transmission electron microscope were used to characterize the composite photocatalysts. This study investigates the oxidative degradation of methyl orange, a probe contaminant, by a heterogeneous photo-Fenton-like process over the prepared composite photocatalysts. The CNTs/β-FeOOH composites exhibit remarkably enhanced photocatalytic activity toward the degradation of methyl orange in water under visible light irradiation as compared with bare β-FeOOH. The added CNTs have triple crucial roles in the promotion of photocatalytic activity of β-FeOOH. One is to trap electrons and effectively hinder recombination of the photoexcited carriers. Two is to act as a dispersing support to control the particle size of β-FeOOH in the CNTs/β-FeOOH composites. Three is to enhance the visible light absorption intensity. Finally, the catalytic mechanism of CNTs/β-FeOOH composite is proposed.

Preparation Conditions on Adsorption and Photocatalytic Activity of TiO2 Particles Prepared by Sol-Gel Method

2011 ◽  
Vol 230-232 ◽  
pp. 131-135
Author(s):  
Wen Jie Zhang ◽  
Yang Yu
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Photocatalytic Degradation ◽  
Degradation Rate ◽  
Irradiation Time ◽  
Sol Gel ◽  
Time Range ◽  
Optimal Composition ◽  
Preparation Conditions ◽  
Sol Gel Process

The amounts of ethanol, HCl and H2O, and also calcination conditions during sol-gel process of preparing TiO2 photocatalyst were investigated. Methyl orange adsorption on TiO2 prepared using different sol compositions is not more than 4% by varying the amount of ethanol, HCl and H2O. The photocatalytic degradation is related to sol composition, and the optimal composition is composed of 10 ml ethanol, 1.0 ml H2O, and 0.1 ml HCl. Calcination temperature and time are also important in TiO2 preparation. The TiO2 particle prepared at 500 °C for 3 h has the optimal photocatalytic activity. In the irradiation time range up to 100 min, photocatalytic degradation rate constantly increases up to 94.2%.

scholarly journals Preparation, Characterization, and Photocatalytic Activity of TiO2/ZnO Nanocomposites

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Liqin Wang ◽  
Xiujun Fu ◽  
Yang Han ◽  
E. Chang ◽  
Haitao Wu ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Physical Adsorption ◽  
Sol Gel ◽  
Composite Catalysts ◽  
Composite Photocatalysts ◽  
Structure Morphology ◽  
Sol Gel Process ◽  
Correlation Constant ◽  
Degradation Reaction

Nanoparticles of the TiO2/ZnO composite photocatalysts were prepared via sol-gel process. The crystalline structure, morphology, thermal stability, and pore structure properties of the composite photocatalysts were characterized by XRD, FE-SEM, TG-DTA, and N2physical adsorption measurements. The photocatalytic activity of the composite catalysts was evaluated by photocatalytic degradation reaction of methyl orange (MO) in aqueous solution. The best preparation parameters for the composite photocatalysts were obtained through systematical experiments. Furthermore, the photocatalytic degradation reaction of aqueous MO solution followed the first-order reaction kinetics; the relative equation can be described asln(C0/C)=0.5689t, and the calculated correlation constant (R2) is 0.9937 for the calibration curve.

scholarly journals Green Synthesis of N/Zr Co-Doped TiO2 for Photocatalytic Degradation of p-Nitrophenol in Wastewater

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 235
Author(s):  
Hayette Benkhennouche-Bouchene ◽  
Julien G. Mahy ◽  
Cédric Wolfs ◽  
Bénédicte Vertruyen ◽  
Dirk Poelman ◽  
...  
Keyword(s):  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Sol Gel ◽  
Visible Region ◽  
Chemical Properties ◽  
Pure Tio2 ◽  
Molar Ratio ◽  
Xps Spectra ◽  
Doped Tio2 ◽  
Co Doped

TiO2 prepared by a green aqueous sol–gel peptization process is co-doped with nitrogen and zirconium to improve and extend its photoactivity to the visible region. Two nitrogen precursors are used: urea and triethylamine; zirconium (IV) tert-butoxide is added as a source of zirconia. The N/Ti molar ratio is fixed regardless of the chosen nitrogen precursor while the quantity of zirconia is set to 0.7, 1.4, 2, or 2.8 mol%. The performance and physico-chemical properties of these materials are compared with the commercial Evonik P25 photocatalyst. For all doped and co-doped samples, TiO2 nanoparticles of 4 to 8 nm of size are formed of anatase-brookite phases, with a specific surface area between 125 and 280 m2 g−1 vs. 50 m2 g−1 for the commercial P25 photocatalyst. X-ray photoelectron (XPS) measurements show that nitrogen is incorporated into the TiO2 materials through Ti-O-N bonds allowing light absorption in the visible region. The XPS spectra of the Zr-(co)doped powders show the presence of TiO2-ZrO2 mixed oxide materials. Under visible light, the best co-doped sample gives a degradation of p-nitrophenol (PNP) equal to 70% instead of 25% with pure TiO2 and 10% with P25 under the same conditions. Similarly, the photocatalytic activity improved under UV/visible reaching 95% with the best sample compared to 50% with pure TiO2. This study suggests that N/Zr co-doped TiO2 nanoparticles can be produced in a safe and energy-efficient way while being markedly more active than state-of-the-art photocatalytic materials under visible light.

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