Comparison of CO2 Reduction Performance with NH3 and H2O between Cu/TiO2 and Pd/TiO2

The aim of this study is to clarify the effect of doped metal type on CO2 reduction characteristics of TiO2 with NH3 and H2O. Cu and Pd have been selected as dopants for TiO2. In addition, the impact of molar ratio of CO2 to reductants NH3 and H2O has been investigated. A TiO2 photocatalyst was prepared by a sol-gel and dip-coating process, and then doped with Cu or Pd fine particles by using the pulse arc plasma gun method. The prepared Cu/TiO2 film and Pd/TiO2 film were characterized by SEM, EPMA, TEM, STEM, EDX, EDS and EELS. This study also has investigated the performance of CO2 reduction under the illumination condition of Xe lamp with or without ultraviolet (UV) light. As a result, it is revealed that the CO2 reduction performance with Cu/TiO2 under the illumination condition of Xe lamp with UV light is the highest when the molar ratio of CO2/NH3/H2O = 1:1:1 while that without UV light is the highest when the molar ratio of CO2/NH3/H2O = 1:0.5:0.5. It is revealed that the CO2 reduction performance of Pd/TiO2 is the highest for the molar ratio of CO2/NH3/H2O = 1:1:1 no matter the used Xe lamp was with or without UV light. The molar quantity of CO per unit weight of photocatalyst for Cu/TiO2 produced under the illumination condition of Xe lamp with UV light was 10.2 μmol/g, while that for Pd/TiO2 was 5.5 μmol/g. Meanwhile, the molar quantity of CO per unit weight of photocatalyst for Cu/TiO2 produced under the illumination condition of Xe lamp without UV light was 2.5 μmol/g, while that for Pd/TiO2 was 3.5 μmol/g. This study has concluded that Cu/TiO2 is superior to Pd/TiO2 from the viewpoint of the molar quantity of CO per unit weight of photocatalyst as well as the quantum efficiency.

Luminescence and tunable color properties of uniphase white-emitting Sr3B2SiO8:Tm3+/Dy3+/Eu3+ phosphors by energy transfer for UV-excited white LEDs

Multi-color single-phase white emission Sr 3 B 2 SiO 8 :Tm 3+ /Dy 3+ /Eu 3+ fluorescent powders were prepared by solid-state fritting method. The fluorescence performance of Tm 3+ , Dy 3+ and Eu 3+ ions single-activated Sr 3 B 2 SiO 8 phosphors were investigated and they exhibit desirable behaviors in their characteristic emissions. Meanwhile, the energy required for migration from Tm 3+ to Dy 3+ and from Dy 3+ to Eu 3+ in co-doped fluorescent substance was determined by the aids of steady-state and transient-state photoluminescence spectra /decay measurements. The energy transmission process from Tm 3+ to Dy 3+ and Dy 3+ to Eu 3+ has been explored to be a dipole–quadrupole interaction and a dipole-dipole interaction of the resonant type, respectively. More significantly, by tuning the molarity ratio of doping Dy 3+ /Eu 3+ ions, multicolor emission from yellow to red shall be achieved in Sr 3 B 2 SiO 8 :Dy 3+ , Eu 3+ phosphors for its potential adhibitions in solid-state lighting applications. The Sr 3 B 2 SiO 8 :Tm 3+ , Dy 3+ samples can implement white light emission by the appropriate changeable doping molar quantity of Tm 3+ and Dy 3+ , applying potentially in white LEDs. The energy migrations between co-doped rare earth ions play a decisive role in these processes.

Active γ –Alumina -Supported Ru Nanoparticles for CO2 Hydrogenation Reaction

A series of alumina supported Ru nanoparticles (Ru γ -Al2O3-x (x=2-10 Ru wt%) was synthesized using the ethylene glycol reduction method. XRD, TEM, EDX, H2-chemisorption, XPS and H2-TPD analytical techniques were used to understand the physiochemical nature of alumina supported Ru nanoparticles. All the well-characterized Ru#Al2O3-x (x=2-10 Ru wt%) catalysts were used for high-pressure CO2 hydrogenation to formic acid synthesis. A clear correlation was recorded between the physiochemical properties of developed catalysts and the molar quantity of formic acid. Among all the developed catalysts, Ru#Al2O3-2 catalyst with or without ionic liquid reaction medium gave a good molar quantity of formic acid. Application of ionic liquid was also expanded, and ionic liquid medium appeared as a good solvent system as compared to the amine solvent system, which not only provides better solubility of reactants and catalysts but also found useful in the easy recovery of formic acid after the completion of the reaction. The catalyst recycled seven times with easy product isolation stem to make this system very useful and fulfill the requirement of sustainable chemistry.

The Varieties of Flow Meters

This chapter discusses the most frequently used flow meters in respirometry. These include the volumetric rotameter, which is affected by ambient temperature and barometric pressure; and the mass flow meter, which directly measures the molar quantity of air passing through it, and thus automatically corrects the volume to standard temperature and pressure. The operation and calibration of each type of meter are discussed.

Hydrogen Permeation Behaviour in Aluminium Alloys

Aluminum alloy is one of the candidates for the liners of compressed hydrogen tank mounted to fuel cell vehicles. It is crucial to elucidate the behavior of hydrogen in the alloy sheet with one side being exposed to hydrogen gas. In the present work, using the hydrogen microprint technique, in 6061 and 7075 aluminum alloy sheets, relationship between hydrogen pressure and the molar quantity of hydrogen emitted from the inside has been investigated. Under any pressure, the quantity of emitted hydrogen is about 10 times smaller in the 7075 alloy than in the 6061 alloy. This indicates that the amount of hydrogen atoms accumulating in the 7075 alloy may be much larger than that in the 6061 alloy.