Papers by Keyword: Wet Oxidation

Abstract: Based on SEM, FT-IR and XRD characterization, the catalyst Pd-Fe-Co-Ce/FSC (ratio 1:1:1:3) was calcined at a temperature of 550°C and a calcination time of 3 h. The catalyst is applied to the catalytic wet oxidation treatment of difficult-to-biodegradable organic waste-water. By the characterization of the catalyst before and after the reuse, it is verified that the SEM morphologis of the catalyst changed little, and the groups contained in the catalyst characterized by FT-IR hardly changed, and the XRD characteristic peaks did not change. From the SEM photos of the catalyst before and after use, the morphology of the catalyst does not change much, and the agglomerated support on the catalyst surface is slightly reduced; the absorption peaks of the FI-IR spectrum of the catalyst before and after use are not significantly different, indicating that the functional groups contained in the catalyst have not changed significantly; After using the catalyst, compared with before use, the characteristic peak shape of each characteristic diffraction did not change significantly. The results show that the catalyst Pd-Fe-Co-Ce/FSC (ratio 1:1:1:3) revealed a stable catalyst performance in the process of CWAO for the treatment of difficult-to-biodegradable organic waste-water.

Abstract: The study is based on the use of NiO as an extended gate of field effect transistor (EGFET) using ITO/glass as a substrate for the sensitivity of pH sensor membrane. The NiO thin film was synthesis by wet and dry thermal oxidation method of Nickel metal thin film deposited by RF sputtering. The sensitivity of the NiO membrane was measured and comparatively analysed against the two different oxidation methods. Structural and morphological properties were investigated for both thin films. The sensitivities measurements of the two membranes were made as pH sensors. The results confirmed that NiO membrane grown by dry oxidation had much better sensitivity (87 μA/pH and 54 mV/pH) compared to wet oxidation membrane sample (52 μA/pH and 48 mV/pH).

Abstract: We studied interface defects of C-face 4H-SiC metal-oxide-semiconductor field-effect transistors (MOSFETs) by means of electrically-detected-magnetic-resonance (EDMR) spectroscopy. EDMR measurements were carried out on opposite types of C-face MOSFETs, which were prepared by dry oxidation and wet oxidation, and we found EDMR signals of interface defects from both the MOSFETs. Judging from their spectroscopic features, the interface signals of the two MOSFETs are assigned to be the same type, and we call them “C-face defects.” The density of C-face defects was found to be larger in the dry-oxide MOSFETs than in the wet-oxide MOSFETs. It is also revealed that part of C-face defects in wet-oxide MOSFETs are coupled with hydrogen atoms.

Abstract: Zinc oxide (ZnO) nanostructures were successfully grown by wet oxidation of zinc (Zn) foil in water at 90 °C for 2 to 8 h. The effect of etching the Zn foil before oxidation treatment on the morphology of ZnO nanostructures was investigated. Hemispherical structures of ZnO nanowires, nanorods and nanotubes were produced on etched Zn foil at different oxidation times. The growth of hemispherical structures was possibly due to the formation of pits along the grains after etching. Without etching, relatively aligned nanorods were formed after wet oxidation with the structure becoming coarser after longer oxidation time. The anisotropic growth ZnO nanostructures on the surface of Zn foil by wet oxidation could be due to the inherent growth habit of ZnO crystal.

Abstract: The technology of the acidification is adopted to prepare arsenic trioxide (As2O3). With a concentration of 98% of concentrated sulfuric acid and Orpiment made into a certain ratio of the slurry suspension. Arsenic trioxide’s content is 99.94%, extraction yield can reach to 98.92%. The optimal conditions is reaction temperature at 120°Cand the reaction time in 2.5 h; the slurry ratio is less than 1/6 and particle size is less than 0.080 mm.

Abstract: We demonstrate that the formation of carbonate-like moiety in SiO₂ could be the origin of negative fixed charge in SiC thermal wet oxidation, based on first-principles calculations. We find that negative CO₃ ion appears in SiO₂ due to not only the existence of residual C atoms that are expected to be emitted from the SiC/SiO₂ interface, but also a large enough number of incorporated H atoms during wet oxidation.

Abstract: Nanocrystalline indium oxide (In₂O₃) thin film was synthesized by thermal evaporation of indium on unheated Si (110) substrates, followed by wet oxidation process. XRD analyses showed the deposited In2O3 film is of high quality and have cubic structure. The Scherrer structural analysis revealed that the In₂O₃ film grown on Si (110) orientation has nanocrystalline structure with crystallite size of 2.53 nm. Photoluminescence (PL) spectrum showed a strong and broad emission at 574.9 nm with two shoulders at 547 nm and 604 nm which related to oxygen vacancies. Finally, the band gap of nanocrystalline In₂O₃ as determined from the PL spectrum was 2.15± 0.15eV.

Abstract: A catalyst based on Fe/active carbon (Fe/AC) and H2O2 as oxidant for the catalytic wet hydrogen peroxide oxidation of phenol in aqueous solution was investigated. The results indicate that the degradation rate of phenol(20mg/L) reach 90.5% in the presence of Fe/AC(2g/L) and hydrogen peroxide (0.5 %) at pH value 7 after 5 hours under normal temperature and atmospheric pressure. Kinetic studies of the degradation reaction show that the degradation rate of phenol nearly follows the first-order reaction. The reaction rate constant and activity energy are 0.4162 min-1 and 23.64 kJ/mol at 25°C, respectively.

Abstract: In order to find out appropriate process for ethanol production from corn stover, wet oxidation（195°C，15 minutes）and simultaneous saccharification and fermentation (SSF) was carried out to produce ethanol. The results showed that the cellulose recovery of 92.9% and the hemicellulose recovery of 74.6% were obtained after pretreatment. 86.5% of cellulose was remained in the solid cake . After 24h hydrolysis at 50°C using cellulase（Cellubrix L）,the achieved conversion of cellulose to glucose was 64.8%. Ethanol production was evaluated from dried solid cake and the hydrolysate was employed as liquid fraction . After 142 h of SSF with substrate concentration of 8% (W/V), ethanol yield of 73.1 % of the theoretical based on glucose in the raw material was obtained by S. cerevisiae(ordinary baker’ yeast) . The corresponding ethanol concentration and volumetric productivity were 17.2g/L and 0.121g/L.h respectively. The estimated total ethanol production was 257.7 kg/ton raw material by assuming consumption of both C-6 and C-5. No obvious inhibition effect occurred during SSF. These instructions give you the basic guidelines for preparing papers for WCICA/IEEE conference proceedings.

Abstract: We studied the annealing process to improve the field-effect channel mobility (μFE) on the 4H-SiC (11-20) face. We found that wet annealing, in which a wet atmosphere was maintained during the cooling-down period to 600°C after wet oxidation, was effective. The interface states (Dit) near the conduction band edge decreased and the μFE increased up to 244 cm2/Vs. Furthermore, the origin of this high channel mobility was investigated using secondary ion mass spectroscopy (SIMS) measurement and thermal desorption spectroscopy (TDS) analysis. It was indicated that the hydrogen density at the MOS interface was increased by the wet annealing and the hydrogen was desorbed mainly at temperatures between 800 °C and 900 °C. These hydrogen desorption temperatures also corresponded to the temperatures of the μFE reduction by argon annealing after the wet annealing. These results indicated that this high channel mobility was achieved by hydrogen passivation during the wet annealing at temperatures between 800 °C and 900 °C.