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1.
La-substituted M-type barium ferrites, Ba1 − x
La
x
Fe12O19, with x = 0.00–0.30 were successfully prepared via a citrate combustion process. Properties of the ceramics were characterized by
powder X-ray diffraction, vibrating sample magnetometry and scanning electron microscopy. XRD patterns revealed only magnetoplumbite
structure without minor phases. With increasing the La substituted content, the saturation magnetization (M
S
) was increased and reached to a maximum at x = 0.15 and then decreased but coercivity (H
C
) was increased. SEM micrographs of the dense ceramics showed the hexagonal platelet shape at low La content and the irregular
shape at high La content. 相似文献
2.
Duangdao Channei Auppatham Nakaruk Wilawan Khanitchaidecha Panatda Jannoey Sukon Phanichphant 《International Journal of Applied Ceramic Technology》2019,16(3):1060-1068
In this work, the coupling of BiVO4 nanoparticles with a highly porous material derived from rice straw (BiVO4/RS composites) and the photocatalytic degradation of 2-chlorophenol (2-CP) in an aqueous solution was studied. The results indicated that BiVO4/RS composites possessed a monoclinic structure. The morphologies of BiVO4/RS composites consisted of spherical shapes of BiVO4 particles coated on the RS adsorbent. The specific surface area of BiVO4 increased from 1.9024 to 31.1153 m2/g after coating with RS adsorbent. A shift occurred in adsorption edge from 510 to 525 nm, corresponding to a reduction in band gap energy from 2.43 to 2.35 eV. The change in the optical adsorption edge and band gap of BiVO4/RS composites may simultaneously result to the duplication of a structure caused by silicon species in rice straw, which was expected to be self-doped into the BiVO4 crystal lattice during synthesis. The photocatalytic performance of 2-chlorophenol under visible irradiation clearly showed that BiVO4/RS composites displayed the highest photocatalytic activities in comparison with other pure samples, which were 2 times higher than that of BiVO4. 相似文献
3.
Fully quantitative analyses of DRIFTS data are required when the surface concentrations and the specific rate constants of reaction (or desorption) of adsorbates are needed to validate microkinetic models. The relationship between the surface coverage of adsorbates and various functions derived from the signal collected by DRIFTS is discussed here. The Kubelka-Munk and pseudoabsorbance (noted here as absorbance, for the sake of brevity) transformations were considered, since those are the most commonly used functions when data collected by DRIFTS are reported. Theoretical calculations and experimental evidence based on the study of CO adsorption on Pt/SiO2 and formate species adsorbed on Pt/CeO2 showed that the absorbance (i.e., = log 1/R', with R' = relative reflectance) is the most appropriate, yet imperfect, function to give a linear representation of the adsorbate surface concentration in the examples treated here, for which the relative reflectance R' is typically > 60%. When the adsorbates lead to a strong signal absorption (e.g., R' < 60%), the Kubelka-Munk function is actually more appropriate. The absorbance allows a simple correction of baseline drifts, which often occur during time-resolved data collection over catalytic materials. Baseline corrections are markedly more complex in the case of the other mathematical transforms, including the function proposed by Matyshak and Krylov (Catal. Today 1995, 25, 1-87), which has been proposed as an appropriate representation of surface concentrations in DRIFTS spectroscopy. 相似文献
4.
Theerakarunwong C Ma ZF Phanichphant S 《Journal of nanoscience and nanotechnology》2012,12(5):3970-3973
Platinum/carbon doped titanium dioxide/single-walled carbon nanotubes (Pt/C/TiO2/SWNTs) were successfully prepared by blending method. These composite catalysts were found to exhibit an anatase TiO2 structure with uniform Pt/C and the existence of SWNTs can be confirmed by transmission electron microscopy (TEM). The composite of Pt/C with TiO2/SWNTs could improve an enhancement in catalytic properties upon applying TiO2/SWNTs as catalyst support. The catalytic oxidation of methanol of Pt/C doped TiO2/SWNTs is found to be higher as compared to the undoped and Pt/C doped materials. 相似文献
5.
Thanittha Samerjai Chaikarn Liewhiran Anurat Wisitsoraat Adisorn Tuantranont Chanitpa Khanta Sukon Phanichphant 《International Journal of Hydrogen Energy》2014
Unloaded and 0.25–1.0 wt% Pt-loaded WO3 nanoparticles were synthesized by hydrothermal method using sodium tungstate dihydrate and sodium chloride as precursors in an acidic condition and impregnated using platinum acetylacetonate. Pt-loaded WO3 films on an Al2O3 substrate with interdigitated Au electrodes were prepared by spin-coating technique. The response of WO3 sensors with different Pt-loading concentrations was tested towards 0.01–1.0 vol% of H2 in air as a function of operating temperature (200–350 °C). The 1.0 wt% Pt-loaded WO3 sensing film showed the highest response of ∼2.16 × 104 to 1.0 vol% H2 at 250 °C. Therefore, an operating temperature of 250 °C was optimal for H2 detection. The responses of 1.0 wt% Pt-loaded WO3 sensing film to other flammable gases, including C2H5OH, C2H4 and CO, were considerably less, demonstrating Pt-loaded WO3 sensing film to be highly selective to H2. 相似文献
6.
Piched Anuragudom Jad El‐daye Pawilai Chinwangso Rigoberto C Advincula Sukon Phanichphant T Randall Lee 《Polymer International》2011,60(4):660-665
A new conjugated light‐emitting AB copolymer containing alternating fluorene and naphthalene units, poly{(9,9‐di‐n‐octylfluorenediyl vinylene)‐alt‐[1,5‐(2,6‐dioctyloxy)naphthalene vinylene]} (PFV‐alt‐PNV), was synthesized via Horner‐Emmons polymerization. The polymer is completely soluble in common organic solvents and exhibits good thermal stability up to 400 °C. UV‐visible, fluorescence and photoluminescence measurements of the copolymer show peak maxima at 427, 500 and 526 nm, respectively. A light‐emitting device containing the new polymer was fabricated using a simple indium tin oxide configuration: (ITO)/PEDOT:PSS/PFV‐alt‐PNV/Al. Measurements of current versus electric field were carried out, with an onset of light emission occurring at 2.5 V. The electroluminescence brightness was observed to reach a maximum of 5000 cd m?2. Copyright © 2011 Society of Chemical Industry 相似文献
7.
The properties of magnesium ferrites, Mg1 ? x Zn x Fe2O4 with 0.0 ≤ x ≤ 0.5, were investigated by means of powder X-ray diffraction, magnetization, Mössbauer spectroscopy, and scanning electron microscopy. The ferrites were prepared by conventional solid-state reaction using a mixed oxide method. All XRD patterns revealed only the monophasic spinel characteristic structure of MgFe2O4. The lattice parameters increased with the increasing of Zn content. Saturation magnetization (M S ) of the ferrites was discussed with respect to Zn substitution. M S values increased with Zn content up to x = 0.35 and then decreased thereafter. Mössbauer results showed Fe3 + ion distribution between tetrahedral and octahedral sites and the effect of Zn ions on ferrimagnetic order. The line-broadening of the Mössbauer spectra increased with substituting Mg with Zn ions due to disruption of the local magnetic order. The SEM micrographs of the sintered bodies showed irregular shape in the order of ~5–6 μm. 相似文献
8.
K. Wetchakun T. Samerjai N. Tamaekong C. Liewhiran C. Siriwong V. Kruefu A. Wisitsoraat A. Tuantranont S. PhanichphantAuthor vitae 《Sensors and actuators. B, Chemical》2011,160(1):580
This article extensively reviews the recent development of semiconductor metal oxide gas sensors for environmentally hazardous gases including NO2, NO, N2O, H2S, CO, NH3, CH4, SO2 and CO2. The gas sensing properties of differently-prepared metal oxides and loaded metal oxides towards nine environmentally hazardous gases have been individually compared and digested. Promising materials for sensitive and selective detection of each hazardous gas have been identified. For instance, unloaded WO3 nanostructures are the most promising candidates for NO2 sensing while metal catalyst loaded WO3 and gold-loaded SnO2 sensors are among the most effective for NO and N2O sensing, respectively. Moreover, related gas-sensing mechanisms are comprehensively discussed. 相似文献
9.
Development of an electrochemical‐surface plasmon dual biosensor based on carboxylated conducting polymer thin films 下载免费PDF全文
Saengrawee Sriwichai Rapiphun Janmanee Sukon Phanichphant Kazunari Shinbo Keizo Kato Futao Kaneko Tadashi Yamamoto Akira Baba 《应用聚合物科学杂志》2018,135(1)
A biosensing platform based on the covalent attachment of biomolecules on electropolymerized carboxylated conducting polymers, poly(3‐aminobenzoic acid) and poly(3‐pyrrole carboxylic acid), were developed for the selective simultaneous detection of two biomolecules using electrochemical‐surface plasmon resonance (EC–SPR) spectroscopy. The surface morphology of the developed biosensors was studied by scanning electron microscopy and atomic force microscopy. The EC–SPR dual biosensor was developed for the label‐free, simultaneous, and selective detection of glucose and human immunoglobulin G (IgG). A change in current density was clearly observed after the injection of glucose, whereas a change in SPR reflectivity was clearly observed after the injection of human IgG. The present work demonstrates the potential of this biosensing platform for real sample analysis in the future. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45641. 相似文献
10.
The effects of aging via gas-phase oxidation and heterogeneous/multiphase reactions on the composition and volatility of secondary organic aerosol (SOA) were investigated in a series of environmental chamber experiments. SOA was formed from the reaction of n-pentadecane, a C15 intermediate volatility alkane, with OH radicals in the presence of NOx under conditions corresponding to ~1.5 and ~15 h of daytime oxidation, and analyzed using a suite of real-time and offline methods. Functional group analysis indicated that the average number of nitrate, hydroxyl, carbonyl, carboxyl, ester, acylperoxynitrate, and methylene groups per C15 molecule were 0.84, 1.07, 0.25, 0.00, 0.00, 0.00, and 12.84 in less aged SOA and 1.25, 0.69, 0.32, 0.00, 0.33, 0.10, and 12.27 in more aged SOA, and the corresponding O/C, H/C, and N/C ratios determined by offline elemental analysis were 0.32, 2.20, and 0.062, and 0.31, 1.86, and 0.061, respectively, similar to each other and in good agreement with values calculated from functional group composition. Time-dependent SOA yields and temperature-programmed thermal desorption (TPTD) analysis showed that the more aged SOA was much less volatile and more chemically complex, and when combined with particle mass spectra indicated that the major SOA components included 1,4-hydroxynitrates, cyclic hemiacetals (CHA), cyclic hemiacetal nitrates (CHAN), and related compounds, as well as hemiacetal (HA) and acetal oligomers. The effects of aging on functional group composition were due primarily to dehydration of CHA and formation of second- and third-generation products via gas-phase OH radical reactions, whereas SOA volatility was reduced primarily by enhanced formation of HA and acetal oligomers through heterogeneous/multiphase reactions involving these multigeneration products. These results can be explained using well-established gas-phase and heterogeneous/multiphase reaction mechanisms. Copyright 2013 American Association for Aerosol Research 相似文献