Preliminary Study of Isotopic Methanes Analysis by Laser Raman Spectroscopy for In-Situ Measurement at Fusion Fuel Gas Processing

Application of laser Raman spectroscopy for fusion fuel gas processing was studied by measuring isotopic methanes exchanged with hydrogen isotopes, which are considered to be a major impurities in the processing. For experimental gases, isotopically equilibrated deuterium and methane were prepared in the presence of solid catalyst. Large Raman scattering peaks of v ₁, bands were observed at 2,917 cm^?1 for CH₄ and at 2,100-2,200 cm_?1 for deuterated derivatives of methane C(H,D)₄. Under a spectral resolution of 5 cm_?1, the v ¹ bands of CH₃D and CH₂D₂ were observed as an overlapped peak, the relative absolute Raman intensity ratio of each isotopic methane was obtained as CH₄: CH₃D+CH₂D₂: CHD₃: CD₄=230: 74: 144: 100. On the other hand, the Raman intensity ratio obtained from pure deuterated standard methane was CH₄: CH₃D: CH₂D₂: CHD₃: CD₄=230: 53: 33: 115: 105. It was confirmed that isotopically equilibrated hydrogen isotopes and methane mixed gas would be applicable for an alternative standard gas for fusion fuel processing gas analyzing system.     

Synthesis of Cu-Doped Mixed-Phase TiO2 with the Assistance of Ionic Liquid by Atmospheric-Pressure Cold Plasma

An atmospheric-pressure dielectric barrier discharge(DBD) gas-liquid cold plasma was employed to synthesize Cu-doped TiO_2 nanoparticles in an aqueous solution with the assistance of[C_2MIM]BF_4 ionic liquid(IL) and using air as the working gas.The influences of the discharge voltage,IL and the amount of copper nitrite were investigated.X-ray diffraction,N_2adsorption-desorption measurements and UV-Vis spectroscopy were adopted to characterize the samples.The results showed that the specific surface area of TiO_2 was promoted with Cu-doping(from 57.6 m~2·g~(-1) to 106.2 m~2·g~(-1) with 3%Cu-doping),and the content of anatase was increased.Besides,the band gap energy of TiO_2 with Cu-doping decreased according to the UV-Vis spectroscopy test.The 3%Cu-IL-TiO_2 samples showed the highest efficiency in degrading methylene blue(MB) dye solutions under simulated sunlight with an apparent rate constant of 0.0223 min~(-1),which was 1.2 times higher than that of non-doped samples.According to the characterization results,the reasons for the high photocatalytic activity were discussed.     

Exploring the cooperation effect of DBD byproducts and Ag/TiO2 catalyst for water treatment in an APPJ system

In this paper,the collective effects of combining heterogeneous Ag/TiO_2 nanocomposite catalyst with the byproducts(primarily the irradiation and the O_3 species) of an atmospheric pressure plasma jet(APPJ) system on the degradation of methyl orange(MO) were explored.The heterostructured Ag/TiO_2 nanocomposite was achieved via decorating the Ag quantum dots(QDs) on the commercially available TiO_2catalyst(P25) through a hydrothermal method.The x-ray diffraction analysis of the nanocomposite catalyst showed the diffraction peaks at 44.3°,64.4°,and 77.5°,corresponding to the Ag planes of(200),(220) and(311),respectively.The high resolution transmission electron microscope characterization of the nanocomposite catalyst indicated that the Ag QDs with an average diameter of 5 nm were homogeneously distributed on the P25 surface.The experimental results on the MO photodegradation showed that the APPJ irradiation had a marginal effect on the cleavage of the MO molecules.When the Ag/TiO_2 nanocomposite catalyst was used,the photodegradation rate of MO increased about 5 times.When both the APPJ byproducts and the Ag/TiO_2 nanocomposite catalyst were used,however,over 90% of the MO in the tested solution was cleaved within 15 min,and the energy efficiency was about 0.6 g/k W h.Moreover,an optimal Ag dosage value was determined(6 wt%).The catalytic results indicated that combining the DBD plasma byproducts with heterogeneous nanocomposite catalysts may be an effect protocol for decreasing the application cost of the DBD system and mitigating the environment pollution by organic dyes in the textile industry.