http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Visible light-irradiated degradation of alachlor on Fe-TiO_2 with assistance of H_2O_2
Kitirote Wantala,Nurak Grisdanurak,Pongtanawat Khemthong,Jatuporn Wittayakun 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.11
0.1 Fe/Ti mole ratio of Fe-TiO_2 catalysts were synthesized via solvothermal method and calcined at various temperatures: 300, 400, and 500 ℃.The calcined catalysts were characterized by XRD, N_2-adsorption-desorption, UVDRS,XRF, and Zeta potential and tested for photocatalytic degradation of alachlor under visible light. The calcined catalysts consisted only of anatase phase. The BET specific surface area decreased with the calcination temperatures. The doping Fe ion induced a red shift of absorption capacity from UV to the visible region. The Fe-TiO_2 calcined at 400 ℃ showed the highest photocatalytic activity on degradation of alachlor with assistance of 30 mM H_2O_2 at pH 3under visible light irradiation. The degradation fitted well with Langmuir-Hinshelwood model that gave adsorption coefficient and the reaction rate constant of 0.683 L mg^−1 and 0.136 mg/L·min, respectively.
Characteristics and photocatalytic degradation of methyl orange on Ti-RH-MCM-41 and TiO2/RH-MCM-41
Surachai Artkla,Kitirote Wantala,Bang-orn Srinameb,Nurak Grisdanurak,Wantana Klysubun,Jatuporn Wittayakun 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.6
Our purpose was to synthesize, characterize and test photodegradation of methyl orange on two catalysts containing 10 wt% titanium supported on mesoporous MCM-41 synthesized with rice husk silica. The first catalyst was Ti-RH-MCM-41 prepared by adding tetrabutyl orthotitanate (TBOT) in a synthetic gel of RH-MCM-41, and the second catalyst was TiO2/RH-MCM-41 prepared by grafting TBOT on the preformed RH-MCM-41. The mesoporous structures were observed on both catalysts and they had surface area of 1,073 and 1,006 ㎡/g. The Ti in Ti-RHMCM- 41 was in the form of Ti(IV) with tetrahedral geometry residing in the mesoporous structure. This form was less active for photodegradation of methyl orange than the other one. The Ti in TiO2/RH-MCM-41 was anatase titania with octahedral geometry located outside the mesoporous framework. This form was more an active phase for the photodegradation and the reaction parameters on this catalyst were further investigated. The optimum catalyst weight to methyl orange volume ratio was 5 g/L and the optimum initial concentration of the dye was 2.0 ppm. The degradation rate obeyed pseudo-first order and the adsorption of methyl orange on TiO2/RH-MCM-41 obeyed Langmuir isotherm.
Rattabal Khunphonoi,Kitirote Wantala,Nurak Grisdanurak 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.1
Copper sulfide was prepared by a hydrothermal method at 130°C. The copper to sulfur molar ratio (6-10) and ageing time (24-72 h) were their synthesis parameters. The obtained materials were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), transmission electron microscope (TEM), UV-DR spectroscopy and X-ray photoelectron spectroscopy (XPS). In order to obtain monocopper sulfide, CuS, named as covellite, the molar recipe ratio of sulfur to copper should be less than 8 in any hydrothermal ageing time. The morphology showed spherical-like structure with energy band gap of 1.88-2.04 eV. CuS was tested for its photocatalytic degradation of paraquat under visible light irradiation. It exhibited excellent activities in the presence of H₂O₂. The kinetic of paraquat degradation was also investigated using Langmuir-Hinshelwood-Hougen-Watson (LHHW) model. The reaction rate constant was three times higher than TiO₂ under the same studied conditions.
Iraj Jodan,Kitirote Wantala,Nader Amini,Behzad Shahmoradi,Mona Ghaslani,이승목,Jixiang Yang,Shivaraju Harikaranahalli Puttaiah 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.9
The harmful and destructive effects of excessive consumption of thiourea in various industries and agriculture have caused health and environmental concerns. Hence, attention has been paid to the need for analysis and detection thiourea at very low concentrations. The aim of this study was to determine the efficiency of electrochemical sensor based on glass carbon electrode modified with Ag nanoparticles and alizarin yellow to detect thiourea as a pollutant. Glass carbon electrode was first modified by alizarin yellow polymer and Ag nanoparticles through electropolymerization and chronoamperometry methods, respectively. The characteristics of the modified electrode were determined through FESEM and EDAX analysis and thiourea concentration was measured through cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. The results showed that the linear range, limit of detection, and sensitivity were 10 to 940 M, 3.3 M and 0.181 A/M, respectively. The stability and reproducibility of the sensor response as well as the interference effect of some anion species were investigated on the performance of the sensor in determining thiourea. The results indicate the optimum stability and reproducibility and no interference effect of the studied species on efficiency of the sensor in determining thiourea.
Effect of Fe^(3+) doping on the performance of TiO_2 mechanocoated alumina bead photocatalysts
Cyril Jose Escopete Bajamundi,Nurak Grisdanurak,Maria Lourdes Pascual Dalida,Kitirote Wantala,Pongtanawat Khemthong 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.8
Ferric ion was introduced to the commercial photocatalyst P25 (Degussa) by ultrasonic wet impregnation technique. The concentration of the dopant was varied from 0.0 to 3.0% Fe/Ti ratio. The doped TiO_2 was then loaded to alumina balls using mechanical coating technique and followed by calcination in air at 400, 450, 500 and 550 ℃. The fabricated photocatalyst was characterized by X-ray diffraction, N_2 adsorption-desorption isotherms, scanning electron microscopy, UV-Vis diffuse reflectance spectroscopy, X-ray adsorption near edge structure and photoluminescence spectroscopy. The photocatalytic activity was tested by following the degradation of methylene blue (MB). It was found that the Fe^(3+) doped TiO_2/Al_2O_3 has a combination of anatase and rutile phase and free of iron oxide phases. The optimum calcination temperature is 400℃ with 0.1% Fe^(3+) concentration. The catalyst addresses the entrainment in photocatalytic reactors, eliminating the need for a post filtration process.