Titania-Phosphotungstic Acid Nanocomposites Dispersed Homogeneously in Mesopores as the Recyclable Photocatalyst

2010 ◽  
Vol 152-153 ◽  
pp. 202-207
Author(s):  
Hua Lan Zhou ◽  
Sha Wu ◽  
Zhong Zou ◽  
Qin Qin ◽  
Wen Jian Shi
Keyword(s):  
Photocatalytic Activity ◽  
Phosphotungstic Acid ◽  
Sol Gel ◽  
Particle Growth ◽  
Tio2 Particle ◽  
Composite Catalyst ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Calcination Process ◽  
Transmission Electron

Heterogeneous photocatalytic materials, titania–phosphotungstic acid nanocomposites in the mesopores of SBA-15 (TiO2-H4PW12O40/SBA15) were prepared by sol–gel method. Compositions and structures of the nanocomposites were characterized by X-ray diffraction (XRD), UV-visible absorption spectroscopy and transmission electron microscopy (TEM). Uniform mesoporous SBA15 consisting of long-range channels provides the immobilization of titania-phosphotungstic acid nanocomposites. The photocatalytic activity of the prepared TiO2-H4PW12O40/SBA15 powders was evaluated from an analysis of the photocatalytic degradation of methyl orange. The results indicated that photocatalytic activity increased with the amount of H4PW12O40 from 0% to 10% and decreased when the amount of H4PW12O40 was above 10%. It is due to the synergetic reaction of H4PW12O40 and TiO2. However, much more H4PW12O40 can occupy the active center of TiO2. TiO2 can inhibit the decomposition of H4PW12O40 in the TiO2-H4PW12O40/SBA15 composites. On the other hand, H4PW12O40 repressed the TiO2 particle growth during calcination process. The composite catalyst also had the advantage of easily being recovered and reused.

Low-Temperature Synthesis of Nano-Crystalline ZnTiO3 Powders by Aqueous Sol-Gel Process

2014 ◽  
Vol 543-547 ◽  
pp. 3741-3744
Author(s):  
Quan Jing Mei ◽  
Cong Ying Li ◽  
Jing Dong Guo ◽  
Gui Wang ◽  
Hai Tao Wu
Keyword(s):  
Sol Gel ◽  
Zinc Nitrate ◽  
X Ray Diffraction ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
Calcination Process ◽  
X Ray ◽  
Nano Crystalline ◽  
Transmission Electron ◽  
Sol Gel Process

The ecandrewsite-type ZnTiO3was successfully synthesized by the aqueous sol-gel method using TiO2dioxide and zinc nitrate as starting materials instead of expensive organic solvent and metal alkoxides. The as-prepared nanopowders were characterized by X-ray diffraction (XRD), differential thermal analysis (DTA) and transmission electron microscopy (TEM), respectively. The results showed that the calcination process of gel consisted of a series of oxidation and combustion reactions, accompanied by significantly exothermal effects. Highly reactive nanosized ZnTiO3powders were successfully obtained at 850 °C with particle size ~50 nm. By comparison, the aqueous sol-gel process was the most effective and least expensive technique used for the preparation of ZnTiO3nanopowders.

Photocatalytic Analysis and Characterization of Zn2SnO4 Nanoparticles Synthesized via Hydrothermal Method with Na2CO3 Mineralizer

2010 ◽  
Vol 97-101 ◽  
pp. 19-22 ◽  
Author(s):  
Yu Shiang Wu ◽  
Wen Ku Chang ◽  
Min Jou
Keyword(s):  
Photocatalytic Activity ◽  
Hydrothermal Process ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Transmission Electron ◽  
Excellent Photocatalytic Activity ◽  
Face Centered ◽  
Xrd Patterns

Zinc stannate Zn2SnO4 (ZTO) nanoparticles were synthesized via a hydrothermal process utilizing sodium carbonate (Na2CO3) as a weak basic mineralizer. The samples were hydrothermally treated at 150, 200, and 250oC for 48 h. The X-ray diffraction (XRD) patterns show that the highly-crystalline ZTO nanostructure could be formed in a well-dispersed manner for the 250°C sample at a particle size of less than 50 nm. As determined from transmission electron microscopy (TEM) results, ZTO nanoparticles are face-centered cubic single crystals agglomerated together. The Raman spectra results showed that the ZTO nanocrystals have a spinel structure. Furthermore, photocatalytic activity was tested with methylene blue (MB) by UV irradiation. The ZTO synthesized by the 2 M Na2CO3 mineralizer at 250oC demonstrated excellent photocatalytic activity. The ZTO treated three different ways had three distinct UV-Visible absorption curves, which directly influences their corresponding photocatalytic activity.

Effect of Rb+ -Doping on the Crystallization, Phase Transition and Photocatalytic Activity of Nanosized TiO2 Catalyst

2012 ◽  
Vol 476-478 ◽  
pp. 954-957 ◽  
Author(s):  
Zhao Hui Ni ◽  
Xiao Li Kou ◽  
Xin Yu Ding ◽  
Cun Wang Ge ◽  
Xiao Hui Jing
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Surface Area ◽  
Sol Gel ◽  
Rutile Phase ◽  
Bet Surface Area ◽  
X Rays ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Kinetics Of

In order to study the ion effect on titania phase structure, crystallite size, and photocatalytic activity, Rb+-doped TiO2 nanoparticles were prepared via a modified sol-gel method and characterized by means of X-ray diffraction, Energy Dispersive X-rays spectroscopy and transmission electron microscopy. The photocatalytic activity of the elaborated powders was studied following the degradation of methyl orange. The results indicate that doping Rb+ increases the BET surface area of TiO2 crystals, decreases the crystal size, reduces the diminishing rates of surface area with increasing calcinations temperature, raises the temperature at which anatase changes into rutile phase, and so significantly increases the photocatalytic activity of TiO2. The kinetics of the methyl orange degradation fits Langmuir-Hinshelwood kinetics model well.

scholarly journals Improved Visible Light Photocatalytic Activity for TiO2Nanomaterials by Codoping with Zinc and Sulfur

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Qianzhi Xu ◽  
Xiuying Wang ◽  
Xiaoli Dong ◽  
Chun Ma ◽  
Xiufang Zhang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Sunlight Irradiation ◽  
X Ray ◽  
Transmission Electron ◽  
Photoinduced Charge

S/Zn codoped TiO2nanomaterials were synthesized by a sol-gel method. X-ray diffraction, UV-vis diffuse reflectance spectroscopy, transmission electron microscopy, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy were used to characterize the morphology, structure, and optical properties of the prepared samples. The introduction of Zn and S resulted in significant red shift of absorption edge for TiO2-based nanomaterials. The photocatalytic activity was evaluated by degrading reactive brilliant red X-3B solution under simulated sunlight irradiation. The results showed S/Zn codoped TiO2exhibited higher photocatalytic activity than pure TiO2and commercial P25, due to the photosynergistic effect of obvious visible light absorption, efficient separation of photoinduced charge carriers, and large surface area. Moreover, the content of Zn and S in the composites played important roles in photocatalytic activity of TiO2-based nanomaterials.

scholarly journals Photocatalytic Activity of Nickel Doped CoO Nanocomposite for the Degradation of Azure A Dye

2020 ◽  
Vol 33 (1) ◽  
pp. 240-244
Author(s):  
Nirmal Singh ◽  
Avinash Kumar Rai ◽  
Ritu Vyas ◽  
Rameshwar Ameta
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Degradation Rate ◽  
Dye Degradation ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Azure A ◽  
Transmission Electron ◽  
Working Parameters

Nanocrystalline cobalt(II) oxide doped with nickel was prepared using the sol-gel method and employed as a photocatalyst for azure A dye degradation under visible light. The prepared photocatalyst was analyzed using energy-dispersive X-ray (EDX) spectroscopy, field emission scanning electron microscopy (FESEM), Fourier-transform infrared (FTIR), X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) techniques. The photocatalytic activity of Ni-doped CoO under different working parameters, like concentration, pH, dosage (Ni-doped and undoped CoO), light intensity for the degradation of azure A dye was also optimzed. It was observed that the dye degradation rate improved after doping. Approximately 76% and 85% of azure A dye was degraded within 90 min through undoped and Ni-doped CoO, respectively.

scholarly journals Rare Earth FreeZn3V2O8Phosphor with Controlled Microstructure and Its Photocatalytic Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Hom Nath Luitel ◽  
Rumi Chand ◽  
Toshio Torikai ◽  
Mitsunori Yada ◽  
Takanori Watari
Keyword(s):  
Photocatalytic Activity ◽  
Rare Earth ◽  
Quantum Yield ◽  
Sol Gel ◽  
Emission Spectra ◽  
Host Lattice ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
Visible Absorption ◽  
Pl Emission

Microsphere of rare earth free phosphor,Zn3V2O8, with broadband yellowish white emission was synthesized by combustion route and compared with the hydrothermal, sol-gel, and solid state reaction methods. The phosphor samples were characterized by X-ray diffraction and scanning electron microscopy. UV-visible absorption and photoluminescence (PL) emission and excitation spectra were investigated for these phosphors.Zn3V2O8phosphor containing 10 mol% of H3BO3flux exhibited enhanced PL emission showing broadband from 450 nm to 750 nm. Effect of stoichiometry of Zn and V on the host lattice and its effect on the PL emission spectra were studied. Series of Mg3V2O8,Ca3V2O8, and Sr3V2O8phosphors were also synthesized and compared to theZn3V2O8phosphor in terms of PL emission and internal quantum yield, and it was found thatZn3V2O8is the most efficient phosphor among the other phosphors studied with quantum yield of 60%. The visible light irradiated photocatalytic activity of these phosphors was investigated and it was found that the hydrothermalZn3V2O8exhibited enhanced activity.

scholarly journals Enhancement of Photocatalytic Activity of ZnO/SiO2by Nanosized Pt for Photocatalytic Degradation of Phenol in Wastewater

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
R. M. Mohamed ◽  
M. A. Barakat
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Surface Area ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Phenol Degradation ◽  
Synthetic Wastewater ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

ZnO- nanoparticles were synthesized by a sol-gel technique from and tetraethyl orthosilicate (TEOS). The synthesized samples were further modified by nanosized Pt from H2PtCl6solution through photoassisted deposition (PAD) and impregnation (Img) routes. The obtained samples were characterized by a series of techniques including X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy, N2adsorption, extended X-ray absorption fine structure (EXAFS), and transmission electron microscopy (TEM). The photocatalytic activity of the Pt-ZnO/ was evaluated by photocatalytic degradation of phenol in synthetic wastewater under UV-irradiation. Results obtained revealed that the surface area and the photocatalytic activity of the prepared samples were increased in the order ZnO/ < PAD: Pt-ZnO/ < img: Pt-ZnO/. The surface area decreased from 480 to 460 and 450 m2/g, while the efficiency of the phenol degradation increased from 80 to 85 and 100%, with the ZnO/, Img: Pt-ZnO-, and PAD: Pt-ZnO- samples, respectively.

RUTHENIUM DOPED ZnO SEMICONDUCTOR: SYNTHESIS, CHARACTERIZATION AND PHOTODEGRADATION OF AZO DYE

2013 ◽  
Vol 12 (02) ◽  
pp. 1350009 ◽  
Author(s):  
K. R. ARANGANAYAGAM ◽  
S. SENTHILKUMAAR ◽  
N. GANAPATHI SUBRAMANIAM ◽  
T. WANG KANG
Keyword(s):  
Photocatalytic Activity ◽  
High Resolution ◽  
Azo Dye ◽  
Heterogeneous Reaction ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Elementary Chemical Reaction ◽  
Doped Zno ◽  
Cr Concentration

Ruthenium doped zinc oxide was synthesized by a simple sol–gel method via ultrasonication. The samples were characterized by X-ray diffraction, high resolution scanning electron microscopy (HR-SEM), high resolution transmission electron microscope (HR-TEM), energy dispersive spectroscopy (EDS) and UV-visible spectroscopy techniques and tested for the feasibility as a heterogeneous photocatalyst. The photocatalytic activity of Ru doped ZnO was tested using an azo dye, congo red (CR) in an aqueous solution, as a model compound. For comparison, the photocatalytic activity of pure ZnO was also performed. The parameters studied include the effect of initial CR concentration, photocatalyst weight and charge transfer phenomenon. The observed reaction mechanism was rationalized based on the elementary chemical reaction occurring in the irradiated heterogeneous reaction mixture. Total mineralization of CR was observed for both pure and Ru doped ZnO system. However, the photocatalytic activity of Ru doped ZnO was found to be higher than that of a pure ZnO .

Synthesis of LaMnO3–Diamond Composites and Their Photocatalytic Activity in the Degradation of Weak Acid Red C-3GN

NANO ◽  
2018 ◽  
Vol 13 (10) ◽  
pp. 1850121 ◽  
Author(s):  
Hao Huang ◽  
Benqian Lu ◽  
Yuanyuan Liu ◽  
Xeuqian Wang ◽  
Jie Hu
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Active Sites ◽  
Sol Gel ◽  
Peak Position ◽  
Weak Acid ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Excellent Photocatalytic Activity ◽  
The Fourier Transform

In this study, a series of LaMnO3–diamond composites with varied LaMnO3 mass contents supported on micro-diamond have been synthesized using a sol–gel method. The as-prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and the Fourier transform infrared spectra (FTIR). Meanwhile, the photocatalytic performances were also tested by photoluminescence (PL) spectroscopy, ultraviolet–visible diffuse reflection spectra (UV-Vis DRS) and the degradation of weak acid red C-3GN (RC-3GN). Results show that the peak position of LaMnO3 is shifted to low angle after the introduction of diamond, and perovskite particles uniformly distributed on the surface of diamond, forming a network structure, which can increase the active sites and the absorption of dye molecules. When the mass ratio of LaMnO3 and diamond is 1:2 (LMO–Dia-2), the composite shows the most excellent photocatalytic activity. This result offers a sample route to enlarge the range of the application of micro-diamond and provide a new carrier for perovskite photocatalysts.

scholarly journals One-Step Synthesis of b-N-TiO2/C Nanocomposites with High Visible Light Photocatalytic Activity to Degrade Microcystis aeruginosa

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 579
Author(s):  
Xu Zhang ◽  
Min Cai ◽  
Naxin Cui ◽  
Guifa Chen ◽  
Guoyan Zou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Chlorophyll A ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Transmission Electron ◽  
One Step

Black TiO2 with doped nitrogen and modified carbon (b-N-TiO2/C) were successfully prepared by sol-gel method in the presence of urea as a source of nitrogen and carbon. The photocatalysts were characterized by field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman, electron paramagnetic resonance (EPR), and UV-vis diffuse reflectance spectra (DRS). The doped nitrogen, introduced defects, and modified carbon played a synergistic role in enhancing photocatalytic activity of b-N-TiO2/C for the degradation of chlorophyll-a in algae cells. The sample, with a proper amount of phase composition and oxygen vacancies, showed the highest efficiency to degrade chlorophyll-a, and the addition of H2O2 promoted this photocatalysis degradation. Based on the trapping experiments and electron spin resonance (ESR) signals, a photocatalytic mechanism of b-N-TiO2/C was proposed. In the photocatalytic degradation of chlorophyll-a, the major reactive species were identified as OH and O2−. This research may provide new insights into the photocatalytic inactivation of algae cells by composite photocatalysts.

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