scholarly journals Fabrication of Bifunctional TiO2/POM Microspheres Using a Layer-by-Layer Method and Photocatalytic Activity for Methyl Orange Degradation

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ping Niu ◽  
Dunqing Wang ◽  
Aili Wang ◽  
Yuhua Liang ◽  
Xinfang Wang
Keyword(s):  
Methyl Orange ◽  
High Efficiency ◽  
Catalyst Concentration ◽  
Magnetic Microspheres ◽  
Layer By Layer ◽  
Methyl Orange Degradation ◽  
X Ray ◽  
First Order ◽  
Composite Catalysts ◽  
Layer Method

Bifunctional films of Keggin-type polyoxometalates H3PW12O40 (PW12), H4SiW12O40 (SiW12), H3PMo12O40 (PMo12), and TiO2 were successfully built on Fe3O4@SiO2 microspheres using a layer-by-layer method. The characterization by field emission scan electronic microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDX) shows that TiO2 nanoparticles and polyoxometalate (POM) anions are successfully assembled. The photodegradation of methyl orange (MO) was used to test the photocatalytic efficiency of magnetic catalysts under UV irradiation. For MO decomposition, multilayer films that combine PW12 and SiW12 with TiO2 show high efficiency, which can be attributed to the synergistic effect between POMs and TiO2. The degradation of the model contaminant was also systematically checked under different conditions such as bilayer number deposited on magnetic microspheres, catalyst concentration, inorganic oxidants, and salts. The oxidation process of MO follows an apparent first-order reaction. Furthermore, the composite catalysts deposited on Fe3O4@SiO2 magnetic microspheres can be conveniently, quickly, and efficiently separated by an external magnet from a solution.

scholarly journals A study on preparation and characterization of carbon doped TiO2 nanotubes

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Srimala Sreekantan ◽  
Roshasnorlyza Hazan ◽  
Zainovia Lockman ◽  
Ishak Mat
Keyword(s):  
Methyl Orange ◽  
Tio2 Nanotubes ◽  
Pure Tio2 ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Methyl Orange Degradation ◽  
Doped Tio2 ◽  
X Ray ◽  
Carbon Doped

The present study is directed to clarify the influence of carbon doping on the degradation of methyl orange. TiO2 nanotubes were prepared by anodizing titanium foils in a two electrode configuration bath with titanium foil as the anode and platinum as the counter electrode. The electrochemical bathconsists of 1 M Na2SO4 with 0.7 g ammonium fluoride, NH4F. The nanotubes obtained were further doped with carbon via in-situ and ex-situ method. Incorporation of carbon on TiO2 via in-situ method is accomplished during the anodization process by introducing oxalic acid into electrolyte while theex-situ doping involves carbon incorporation into pre-fabricated TiO2 nanotube via flame annealing using carbon blackN330. Characterization such as Scanning Electron Microscope (SEM), Energy Dispersive X-ray Analysis (EDX), and X-Ray Diffraction (XRD) are used to determine the surfacemorphology, composition of dopants, and phases exists. Well ordered nanotube with good adherence and smooth surface was obtained for both methods. When the oxide was annealed, X-ray diffraction analysis revealed the presence of anatase and rutile phase. The photocatalytic properties of thepure TiO2 and carbon doped TiO2 were tested for methyl orange degradation and the result indicated that the in-situ doped TiO2 has much better degradation than the ex-situ and pure TiO2. The percentage of methyl orange degradation for in-situ was 20% and 41% higher than ex-situ doped TiO2 and pure TiO2, respectively.

Effect of Mixed-Phase TiO2/PVA Nanofibers on the Degradation on Methyl Orange

2015 ◽  
Vol 1107 ◽  
pp. 353-358
Author(s):  
Norizan Mohammed Lot ◽  
S. Nafisah Md. Rashid ◽  
Umi Sarah Jais ◽  
M. Kamil Abd Rahman
Keyword(s):  
Methyl Orange ◽  
Reaction Rate ◽  
Sol Gel ◽  
Average Diameter ◽  
Mixed Phase ◽  
Electrospinning Technique ◽  
X Ray ◽  
First Order ◽  
Reaction Rate Constants ◽  
Sol Gel Process

We report on the synthesis of nanostructured TiO2for various structural phases and observed the rate of degradation of methyl orange (MO) upon UV irradiation. Mixed phase nanocrystalline TiO2at temperature of 800°C shows higher rate of degradation of MO with the rate of 0.0203/min compared to other phases. This rate corresponds to the percentage of MO degradation of 58.85%, 71.69%, 86.25% and 91.82% for duration of 30, 60, 90 and 120 min of UV irradiations, respectively. The TiO2powder was prepared using titanium (IV) butoxide as the precursor via sol gel process. The samples were characterized using X-ray diffractometer (XRD) and field emission scanning electron microscopy (FESEM). The rate of degradation of MO after UV exposure was measured using UV-Vis spectrophotometer. The first order reaction rate constants (kapp) of anatase; mixed-phase; and rutile phases were 0.0130, 0.0203 and 0.0029, respectively, which shows that mixed-phase TiO2has higherkappvalue indicating higher rate of degradation. The PVA/TiO2nanofibers were produced via electrospinning technique and similar tests on the nanofibers were conducted.Energy dispersive X-ray spectroscopy (EDX) indicates significant presence of TiO2is in nanofibers and the average diameter of the nanofibers was 600 nm.

Influence of anionic surfactant on the process of electro-Fenton decolorized methyl orange

2010 ◽  
Vol 61 (5) ◽  
pp. 1299-1306
Author(s):  
B. X. Ren
Keyword(s):  
Methyl Orange ◽  
Sodium Dodecyl ◽  
Order Reaction ◽  
Fenton Process ◽  
Methyl Orange Degradation ◽  
First Order ◽  
Pseudo First Order ◽  
Kinetics Of ◽  
Sds Surfactant ◽  
Industry Wastewater

The electro-Fenton process has been shown to be very successful to remove dyes from water. However, the influence of other constituents in dyeing industry wastewater, such as Sodium Dodecyl Sulfate (SDS) surfactants, has not been investigated. In this study, the effect of SDS surfactant on the kinetics of Methyl Orange degradation undergoing Electro-Fenton process was investigated. Results show that Methyl Orange degradation rate decreased as SDS concentration (below Critical Micelle Concentration, CMC) increased, which was attributed to the consumption of hydroxyl radicals (˙OH) by surfactants. The kinetics modeling indicates the reaction was the first-order reaction to Methyl Orange even SDS existing. The pseudo first-order rate constants decreased as SDS concentration increased.

scholarly journals Photocatalytic and Photoelectrocatalytic Degradation of Methyl Orange Using Graphite/PbTiO3 Composite

2018 ◽  
Vol 16 (3) ◽  
pp. 347
Author(s):  
Candra Purnawan ◽  
Sayekti Wahyuningsih ◽  
Pramudita Putri Kusuma
Keyword(s):  
Methyl Orange ◽  
Rate Constant ◽  
Order Reaction ◽  
First Order Reaction ◽  
Methyl Orange Degradation ◽  
First Order ◽  
Photoelectrocatalytic Degradation ◽  
Methyl Orange Concentration ◽  
Degradation Reaction ◽  
Radiation Time

Synthesis of graphite/PbTiO3 composite as a catalyst in photodegradation and photoelectrodegradation process of methyl orange have been conducted. The purposes of this research are to study the effect of radiation time, composition of composite, voltage and pH of solution for methyl orange degradation. Photodegradation process of methyl orange was carried out for 5; 10; 15; 20; 25 and 30 min. Ratio of graphite : PbTiO3 (w/w) were varied at 1:3; 1:2; 1:1; 2:1 and 3:1. Meanwhile, the applied voltages were 7.5; 10 and 12.5 V and the photoelectrodegradation was conducted under pH condition of 3; 7; and 11, respectively. The result showed that optimum composition of graphite/PbTiO3 in the methyl orange photodegradation was obtained at 1:1 ratio for 30 min with degradation up to 90.43% ± 0.062. The degradation reaction follows first order reaction with a rate constant of 0.0688 min-1. The optimum voltage is 10 V, in which it reduced the methyl orange concentration up to 92.65% ± 0 with a rate constant 0.0941 min-1 for first order reaction. The optimum pH is pH = 11, that provide methyl orange reduction up to 95.28% ± 0.082.

Self-Assembly of Large Scale CdS/TiO2 Film Photocatalyst

2012 ◽  
Vol 512-515 ◽  
pp. 1692-1698 ◽  
Author(s):  
Chun Xiang Li ◽  
Zhao Hua Jiang ◽  
Zhong Ping Yao
Keyword(s):  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Large Scale ◽  
Crystal Size ◽  
Composite Films ◽  
Atomic Ratio ◽  
Layer By Layer ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Layer Method

CdS/TiO2 composite films with different Cd:Ti atomic ratio were prepared by a new straightforward particulate layer-by-layer method. Titanium dihydroxide and thiourea were used as precursors. Raman and X-ray photoelectron spectroscopy analysis for the composite films revealed that the TiO2 formed from titanium precursor retarded the crystal growth of CdS. Luminescence and UV–vis absorption spectra investigation showed that emission and absorption band of CdS/TiO2 blue shifted as crystal size of CdS decreased. Furthermore, hydrogen formation curves revealed that hydroxyl of CdS/TiO2 films plays an important role in water splitting reaction under both UV and visible light irradiations.

scholarly journals Design Of A Bi-Functional α-Fe2O3/Zn2SiO4:Mn2+ By Layer-By-Layer Assembly Method

2015 ◽  
Vol 60 (2) ◽  
pp. 1165-1167
Author(s):  
Ri Yu ◽  
Juyeon Yun ◽  
Jae-Hwan Pee ◽  
Yoojin Kim
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Coating Process ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Assembly Method ◽  
Layer Method ◽  
Transmission Electron ◽  
Layer Assembly

Abstract This work describes the design of bi-functional α-Fe2O3/Zn2SiO4:Mn2+ using a two-step coating process. We propose a combination of pigments (α-Fe2O3) and phosphor (Zn2SiO4:Mn2+) glaze which is assembled using a layer-by-layer method. A silica-coated α-Fe2O3 pigment was obtained by a sol-gel method and a Zn2+ precursor was then added to the silica-coated α-Fe2O3 to create a ZnO layer. Finally, the Zn2SiO4:Mn2+ layer was prepared with the addition of Mn2+ ions to serve as a phosphor precursor in the multi-coated α-Fe2O3, followed by annealing at a temperature above 1000°C. Details of the phase structure, color and optical properties of the multi-functional α-Fe2O3/Zn2SiO4:Mn2+ were characterized by transmission electron microscopy and X-ray diffraction analyses.

Photocatalytic Activity of TiO2 Coated on HZSM-5 Prepared by Oxalic Acid Treatment

2012 ◽  
Vol 424-425 ◽  
pp. 633-636
Author(s):  
Wen Jie Zhang ◽  
Jin Lei Chen ◽  
Hong Bo He
Keyword(s):  
Methyl Orange ◽  
Oxalic Acid ◽  
Reaction Kinetic ◽  
Kinetic Constant ◽  
Sol Gel ◽  
Methyl Orange Degradation ◽  
First Order ◽  
Maximum Value ◽  
Decoloration Rate ◽  
Degradation Of Methyl Orange

Zeolite HZSM-5 was pre-treated by oxalic acid and used as support for TiO2film prepared by sol-gel method. Decoloration rates increased with TiO2concentration both for pure TiO2and TiO2/HZSM-5. Meanwhile, the total decoloration rate on TiO2/HZSM-5 is much higher than using pure TiO2on all TiO2concentrations. Methyl orange degradation on TiO2/HZSM-5 reached its maximum value at TiO2concentration of 600 mg/l. After 120 min of irradiation, decoloration rate on TiO2/HZSM-5 was near 100%, compared with 50% decoloration on pure TiO2. Photocatalytic degradation of methyl orange on both TiO2/HZSM-5 and TiO2follows the equation of first order reaction. Kinetic constant on TiO2/HZSM-5 is k1=0.02663 min-1, which is much higher than that on pure TiO2, k2=0.010154 min-1.

Effect of anionic surfactants on the process of Fenton degradation of methyl orange

2009 ◽  
Vol 60 (11) ◽  
pp. 2803-2807 ◽  
Author(s):  
C. W. Yang ◽  
D. Wang
Keyword(s):  
Methyl Orange ◽  
Anionic Surfactants ◽  
Sodium Dodecyl ◽  
Degradation Pathway ◽  
Fenton Process ◽  
Methyl Orange Degradation ◽  
First Order ◽  
Kinetics Modelling ◽  
Kinetics Of ◽  
Sds Surfactant

Fenton process has been shown to be very successful to remove dyes from water. However, the influence of other constituents in dyeing industry wastewater, such as Sodium Dodecyl Sulphate (SDS) surfactants, has not been investigated. In this study, the effect of SDS surfactant on the kinetics of Methyl Orange degradation undergoing Fenton process was investigated. Results show that Methyl Orange degradation rate decreased as SDS concentration increased, which was attributed to the consumption of hydroxyl radicals (∙OH) by surfactants and the formation of Methyl Orange-SDS complex. No evidence was found that the Methyl Orange degradation pathway was affected by the presence of SDS. The kinetics modelling indicates the reaction was the first-order reaction to Methyl Orange.

Effect of Univalent Cations Fluoride in F-Sb Codoped SnO2 Electrode on Electro-Catalytic Degradation of Methyl Orange

2012 ◽  
Vol 465 ◽  
pp. 192-197 ◽  
Author(s):  
Lu Sheng Chen ◽  
Yan Yan Liu ◽  
Huai Xiang Li ◽  
Chao Liu ◽  
Kang Wu
Keyword(s):  
Methyl Orange ◽  
Sol Gel ◽  
Catalytic Degradation ◽  
Anode Surface ◽  
Univalent Cations ◽  
X Ray Diffraction ◽  
Methyl Orange Degradation ◽  
X Ray ◽  
Degradation Rates ◽  
Degradation Of Methyl Orange

In this work, F-Sb codoped SnO2film electrode material has been prepared and used as an anode on titanium (Ti) substrate for degradation of methyl orange. The emphasis is laid on the effect of univalent cations fluoride doped during preparation of F-Sn codoped SnO2composites by sol gel method. The facts show that univalent cations fluoride could affects the electro-catalytic degradation rate of methyl orange by F-Sb codoped composite film on the Ti electrode. A promotion to the degradation rates of methyl orange could be observed when KF or NH4F was used as codopant but other fluoride codopant such as LiF, NaF or HF could slow the methyl orange degradation. X-ray diffraction (XRD) and x-ray photo-electron spectroscopy (XPS) were used to study structures and composition of the anode surface.

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