Photocatalytic Degradation of p-Nitroaniline with Composite Photocatalyst H3P12W40/TiO 2

2011 ◽  
Vol 233-235 ◽  
pp. 967-970 ◽  
Author(s):  
Wei Hong Huang ◽  
Rui Liu
Keyword(s):  
Photocatalytic Degradation ◽  
Ph Value ◽  
Chemical Interaction ◽  
Sol Gel ◽  
Diffuse Reflectance Spectrum ◽  
Visible Region ◽  
Impregnation Method ◽  
Composite Photocatalyst ◽  
X Ray ◽  
Ft Ir

The prepared composite photocatalyst H3PW12O40/TiO2 was synthesized by sol-gel impregnation method and characterized by scanning electron microscope(SEM), energy-dispersive X-ray spectroscopy(EDS), Fourier transform infrared(FT-IR), X-ray diffraction(XRD), UV-vis diffuse reflectance spectrum(DRS) to investigate its optical, physical and chemical properties. The results indicated that the modified catalyst was coated with P and W element, still have uniform anatase structure. Meanwhile, there is a chemical interaction exists between the Keggin unit and the surface of the titania matrix. Compared with original H4PW12O40 or TiO2 matrix, the adsorption threshold onset of the composite extended to the visible region. Effects of H3PW12O40/TiO2 dosage, pH value, initial p-NA concentration on the photocatalytic degradation of p-NA under 250W UV irradiation were investigated. The optimal H3PW12O40/TiO2 dosage and pH value for degradation of 10mg/L p-NA were o.6g/L and 3.0, respectively. The degradation rate of p-NA by H3PW12O40/TiO2 process could be fitted pseudo-first-order kinetics. Moreover, 66% degradation of p-NA was still observed in the 5th recycle experiment. Futhermore, 4-Aminophenol, Phenol, Hydroquinone, 4-Benzoquinone and other intermediate products were indentifieded by GC/MS and a possible reaction mechanism is proposed on the basis of all the information obtained from the analysis of FT-IR and the above intermediates.

Chitin/TiO2 Composite for Photocatalytic Degradation of Phenol

2010 ◽  
Vol 132 ◽  
pp. 105-110 ◽  
Author(s):  
Kun Wan ◽  
Xiang Hong Peng ◽  
Ping Jing Du
Keyword(s):  
Photocatalytic Degradation ◽  
Ph Value ◽  
Uv Light ◽  
Sol Gel ◽  
Hplc Method ◽  
Tetrabutyl Titanate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Crystallographic Structures

Chitin/TiO2 composite was prepared through colloid TiO2 deposited on the chitin by controlling the pH value of the system, while colloid TiO2 was synthesized by the sol–gel method using tetrabutyl titanate as a precursor. The structures and morphologies of the chitin/TiO2 composite were characterized by FT-IR, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The photocatalytic degradation of phenol was investigated by HPLC method. The results revealed that the chitin/ TiO2 composite was an efficient photocatalyst for the degradation of phenol, and 99.2% of the phenol was degraded after 6h under UV light. The TiO2 was adsorbed on the chitin by hydrogen and titanoxane bonds between them. Colloid TiO2 was gradually deposited to form the anatase crystallographic structures, showing 2θ = 25.3, 37.8, 47.8 and 54.6. Such biocompatible photocatalyst might be applied in the field of various phenol pollutants abatement.

scholarly journals Visible Light Induced Photocatalytic Degradation of Methyl Red with Codoped Titania

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Susmitha Thota ◽  
Siva Rao Tirukkovalluri ◽  
Sreedhar Bojja
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Anatase Phase ◽  
Sol Gel ◽  
Visible Region ◽  
Oxygen Demand ◽  
Analytical Techniques ◽  
Active Species ◽  
Methyl Red ◽  
X Ray

Photocatalysis using semiconductor oxides was being investigated extensively for the degradation of dyes in effluent water. This paper reports our findings on visible light induced photocatalytic degradation of azo dye, methyl red mediated nitrogen and manganese codoped nano-titanium dioxide (N/Mn-TiO2). The codoped samples with varying weight percentages were synthesized by sol-gel method and characterized by various analytical techniques. The X-ray diffraction data showed that the synthesized samples were in anatase phase with 2θ at 25.3°. UV-visible diffuse reflectance spectral analysis revealed that the presence of dopants in TiO2 caused a significant absorption shift towards visible region and their presence was confirmed by X-ray photoelectron spectral data. The release of hydroxyl radical (major active species in photocatalytic degradation) by the photocatalyst in aqueous solution under visible light irradiation was quantitatively investigated by the photoluminiscent technique (PL). The effect of various experimental parameters like dopant concentration, pH, catalyst dosage, and initial dye concentrations was investigated and optimum conditions were established. The extent of mineralization of methyl red was studied by chemical oxygen demand (COD) assays and the results showed complete mineralization of the dye.

scholarly journals Photocatalytic Degradation of Dichlorvos in Visible Light byMg2+-TiO2Nanocatalyst

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
T. Siva Rao ◽  
Teshome Abdo Segne ◽  
T. Susmitha ◽  
A. Balaram Kiran ◽  
C. Subrahmanyam
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Visible Region ◽  
Sem Images ◽  
Xps Spectra ◽  
X Ray ◽  
Adsorption Desorption

Photocatalytic activity of TiO2was studied by doping with magnesium (Mg2+-TiO2) with varying magnesium weight percentages ranging from 0.75–1.5 wt%. The doped and undoped samples were synthesized by sol-gel method and characterized by X-ray diffraction (XRD), N2adsorption-desorption (BET), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectroscopy (DRS), and scanning electron microscopy (SEM). The XRD data has shown that anatase crystalline phase in Mg2+-TiO2catalysts, indicating that Mg2+ions did not influence the crystal patterns of TiO2. The presence of magnesium ions in TiO2matrix has been determined by XPS spectra. DRS spectra showed that there is a significant absorption shift towards the visible region for doped TiO2. The SEM images and BET results showed that doped catalyst has smaller particle size and highest surface area than undoped TiO2. The photocatalytic efficiency of the synthesized catalysts was investigated by the photocatalytic degradation of aqueous dichlorvos (DDVP) under visible light irradiation, and it was found that the Mg2+-doped catalysts have better catalytic activity than undoped TiO2. This can be attributed that there is a more efficient electron-hole creation in Mg2+-TiO2in visible light, contrary to undoped TiO2which can be excited only in UV irradiation. The effect of dopant concentration, pH of solution, dosage of catalysts, and initial pesticide concentration has been studied.

Preparation and Characterization of H3PW12O40/TiO2-M (M=Fe, Co, Ni, Zn) and Photocatalytic Activity for Methyl Orange Decomposition

2014 ◽  
Vol 1073-1076 ◽  
pp. 202-209 ◽  
Author(s):  
Si Jing Chen ◽  
Qiang Gan ◽  
Hai Ru Shang ◽  
Xia Liu
Keyword(s):  
Methyl Orange ◽  
Metal Ion ◽  
Ph Value ◽  
Anatase Phase ◽  
Sol Gel ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
First Order Kinetics ◽  
Ft Ir ◽  
Catalyst Dosage

Composites H3PW12O40/TiO2-M (M=Fe, Co, Ni, Zn) were synthesized by combining sol-gel technology with impregnation method. The structures and properties were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and UV-Vis diffuser reflectance spectrum (UV-Vis DRS). The XRD and FT-IR results showed that the TiO2 particles had the anatase phase, and the Keggin structure of H3PW12O40 remained intact. The UV-Vis DRS results indicated that compared with pure TiO2, an obvious red shift occurred after introducing H3PW12O40. The composites were used as heterogeneous photocatalyst to the degradation of methyl orange, and the influences of catalyst dosage, H3PW12O40 loading and metal ion species were studied. Results show that, under the optimum parameters pH value 2.00, 0.4 g·L-1 catalyst dosage and 30% H3PW12O40 loading, 96.6% methyl orange was degraded after 30 min irradiation (365 nm) using composite H3PW12O40/TiO2-Zn. The photodegradation process fitted Langmuir-Hinshelwood first order kinetics.

Effects of Precursor pH Value and Calcination Temperature on Photocatalytic Properties of Ni-Fe Codoped ZnO Nanoparticles

2014 ◽  
Vol 1053 ◽  
pp. 165-172
Author(s):  
Qin Zhang ◽  
Jing Quan Zhang ◽  
Ming Xu ◽  
Chun Lai Zhang ◽  
Cheng Jun Dong ◽  
...  
Keyword(s):  
Methyl Orange ◽  
Photocatalytic Degradation ◽  
Calcination Temperature ◽  
Photoelectron Spectroscopy ◽  
Ph Value ◽  
Degradation Mechanism ◽  
Sol Gel ◽  
Precursor Solution ◽  
X Ray ◽  
Zno Powder

(Ni, Fe)-codoped ZnO powder was synthesized by a sol-gel process, using oxalic acid zinc as the zinc source. Effects of the pH value of the precursor solution and the calcination temperature on the photocatalytic degradation efficiency of (Ni, Fe)-codoped ZnO powder were studied by using methyl orange as the degradation object. The structures, morphology and ingredients were characterized by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The results show that all the samples are polycrystalline with a nanocrystal size of about 20~30nm. The methyl orange solution (8 mg/L) was degraded by more than 50% in 12 hours under the irradiation of natural light in the presence of the (Fe, Ni)-codoped ZnO sample synthesized under these conditions: the doping concentrations of both Ni, Fe are 1%, the pH of the precursor solution is 7.5, and the calcination temperature is 375°C. The photocatalytic degradation mechanism of (Ni, Fe)-codoped ZnO powder is discussed qualitatively, based on the microstructure analysis.

Exploring the characteristics of the nickel oxide nanoparticles via Sol - gel method

2020 ◽  
Vol 3 (3) ◽  
Author(s):  
Jothi M ◽  
Sowmiya K
Keyword(s):  
Nickel Oxide ◽  
Ph Value ◽  
Lattice Structure ◽  
Sol Gel ◽  
Systematic Change ◽  
Average Crystalline Size ◽  
Nio Nanoparticles ◽  
Nickel Oxide Nanoparticles ◽  
X Ray ◽  
Vis Spectroscopy

Nickel Oxide (NiO) is an important transition metal oxide with cubic lattice structure. NiO is thermally stable that is suitable for tremendous applications in the field of optic, ceramic,glass, electro-chromic coatings, plastics, textiles, nanowires, nanofibers, electronics,energy technology, bio-medicine, magnetism and so on. In this present study, NiO nanoparticles were successfully synthesized by sol-gel technique. Nano-sols were prepared by dissolving Nickel-Chloride [NiCl2.6H2O] in NaOH solvent and were converted into nano structured gel on precipitation. A systematic change in preparation parameters like calcination temperature, time, pH value has been noticed in order to predict the influence on crystallite size. Then the prepared samples were characterized by the X-ray Diffraction Spectroscopic (XRD), UV-VIS Spectroscopy, Fourier Transform Infra-Red Spectroscopy (FTIR), Energy Dispersive X-ray Spectroscopy (EDX), Scanning Electron Microscopy (SEM) and Particle Size Analyzer (PSA). From XRD, the average crystalline-size has been calculated by Debye-Scherrer Equation and it was found to be 12.17 nm and the band gap energy of Nickel oxide (NiO) from UV studies reveals around 3.85 eV. Further, EDX and FTIR studies, confirm the presences of NiO nanoparticles. The SEM study exhibits the spherical like morphology of Nickel oxide (NiO). Further from PSA, the mean value of NiO nanoparticles has been determined.

Luminescent Properties of Zn2SiO4:Eu3+,Dy3+ Phosphors via Sol-Gel Process

2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi
Keyword(s):  
Thermal Analysis ◽  
Ir Spectra ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Ft Ir

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.

Preparation of Borosilicate Xerogel and Research on its Mineralization

2012 ◽  
Vol 476-478 ◽  
pp. 2059-2062
Author(s):  
Chen Wang ◽  
Ya Dong Li ◽  
Gu Qiao Ding
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Ph Value ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compositional Changes ◽  
Scanning Electron

Tributyl borate was first adopted for the introduction of boron in the preparation of bioactive borosilicate xerogel by sol-gel method. The xerogel reacted continuously in 0.25M K2HPO4 solution with a starting pH value of 7.0 at 37 °C for 1day. The structural, morphologies and compositional changes resulting from the conversion were characterized using X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The results indicated that speed of formation of HA was cut way back on the time with the addition of boron and the induction period for the HA nucleation on the surface of the borosilicate xerogel was short than 1 days. The conversion mechanism of the borosilicate xerogels to hydroxyapaptite was also discussed.

scholarly journals Copper oxide supported on graphene for phodegradation of rhodamine B

2015 ◽  
Vol 11 (4) ◽  
Author(s):  
Nurul Sahida Hassan ◽  
Nurul Jamilah Roslani ◽  
Aishah Abdul Jalil ◽  
Sugeng Triwahyono ◽  
Nur Fatien Salleh ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Copper Oxide ◽  
Photocatalytic Degradation ◽  
Rhodamine B ◽  
Industrial Wastewater ◽  
Water Contamination ◽  
X Ray Diffraction ◽  
Composite Photocatalyst ◽  
X Ray ◽  
First Order

In recent years, dyes are one of the major sources of the water contamination that lead to environmental problems. For instance, Rhodamine B (RhB) which was extensively used as a colorant in textile industries is toxic and carcinogenic. Among many techniques, photocatalytic degradation become the promising one to remove those dyes from industrial wastewater. Recently, graphene has shown outstanding performance in this application due to its intrinsic electron delocalisation which promotes electron transport between composite photocatalyst and pollutant molecules. While, copper oxide (CuO) is well-known has a lower bandgap energies compared to other semiconductors. Therefore, in this study, copper oxide supported on graphene (CuO/G) was prepared and its photocatalytic activity was tested on degradation of RhB. The catalysts were characterized by X-Ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) Spectroscopy. The results showed that the interaction between copper and graphene support could enhance the photocatalytic activity. The 5 wt% CuO/G was found to give the highest degradation (95%) of 10 mg L-1 of RhB solution at pH 7 using 1 g L-1 catalyst after 4 hours under visible light irradiation. The photodegradation followed the pseudo first-order Langmuir-Hinshelwood kinetic model. This study demonstrated that the CuO/G has a potential to be used in photocatalytic degradation of various organic pollutants.

scholarly journals SiO2 Nanoparticles Derived from Arundo Donax L. Ash Composite with TiO2 Semiconductor for Efficient Photocatalytic Dye Reduction

2021 ◽  
Author(s):  
EASWARAN G ◽  
VIJAYAN M ◽  
SIVAKUMAR K
Keyword(s):  
Photocatalytic Degradation ◽  
Visible Region ◽  
Sio2 Nanoparticles ◽  
Arundo Donax ◽  
Composite Sample ◽  
Precipitation Method ◽  
Impregnation Method ◽  
Electron Microscopic ◽  
Crystalline Nature ◽  
Arundo Donax L

Abstract In this report, the biomass derived silicon dioxide (SiO2) nanoparticles composite with titanium dioxide (TiO2) semiconductors used as efficient photocatalyst for degradation of Rhodamine B (RhB) dye molecules under UV-visible light irradiation is proclaimed. At first SiO2 derived from Arundo donax L. ash and TiO2 synthesized using titanium (IV) isopropoxide by co-precipitation method and then their different compositions prepared by wet impregnation method were exampled to various optical and atomic level fundamental studies. The amorphous and crystalline nature of SiO2 and TiO2 ratify from XRD and here it is found that the crystalline nature decreased in their compositions as compared to TiO2. 293 nm UV photons harvesting SiO2 observed which could be due to more impurity states presence on surface is further accomplished red shift after composition with TiO2 lead to moving photons harvesting nature towards visible region. The band gap increases in SiO2/TiO2 composites as for TiO2 composition is rapport well with the aforementioned redshift value. Out of all samples the low recombination rate is procured in 50 wt% SiO2/50 wt% TiO2 composite sample. The separated ~ 100–200 nm sized TiO2 nanoparticle and aggregated tiny SiO2 nanoparticles availability in composite sample is authentically substantiated from electron microscopic studies. The presence of Si, O and Ti elements in composite samples probed by XPS. Following the fundamental studies, the photocatalytic degradation ability of the as-prepared samples has been scrutinized against the degradation of Rh B dye in which the pronounced photocatalytic degradation efficiency 93.7% is successfully achieved on 50 wt% SiO2/50 wt% TiO2 nanocomposite photocatalyst.

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