• Applied Chemistry for Engineering
• /
• v.16 no.3
• /
• pp.385-390
• /
• 2005

In this study, nano sized colloidal Ag was made by using a seed sol method. Colloidal Ag solution was spouted on the surface of the inorganic pigment using the hybridizer system and spray nozzle. Then, the surface of the inorganic pigment was modified by $TiO_2$ to obtain the antibacterial ability. In the manufacturing process of nano sized colloidal Ag, it was confirmed that the size of particles increased by addition of $AgNO_3$ and increased the reaction time. The antibacterial measurement of the inorganic pigment showed that the growth of fungus decreased as the reaction time was increased. After the antibacterial ability appeared, in 5~7 h of the antibacterial inoculation experiment, it was measured that the antibacterial activity was excellent at a fixed time frame. The photodecomposition of benzene using $TiO_2$ as the photocatalyst showed 60~70% efficiency in about 80 min. reaction time. It was shown that more than 90% of this efficiency was achieved in the reaction time of about 30 min.

• Korean Journal of Weed Science
• /
• v.6 no.2
• /
• pp.162-167
• /
• 1986

This experiment was conducted to determine the effect of light, organophosphorus compounds and plant growth regulators on phytotoxicity of pendimethalin (3,4-dimethyl-2,6-dinitro-N-1-ethyl propylamine) in rice (Oryza saliva L.). The phytotoxicity of pendimethalin on post-germination growth of rice was greatly reduced by light treatment. This effect resulted from photodecomposition of pendimethalin. Antidoting activity on phytotoxicity of pendimethalin varied with the kind of organophosphorus compounds used and the application time. The greatest antidoting effect was obtained from edifenphos (0-3thy1 S,S-diphenylphosphorothioate). However, the effect was not observed when edifenphos was applied prior to pendimethalin. There was no antidoting effect of indole acetic acid (IAA), gibberellic acid ($GA_3$) and kinetin used alone, but combinations of 3 ppmw IAA + either 3 or 5 ppmw $GA_3$ and 1 ppmw kinetin + 10 ppmw $GA_3$ reduced the phytotoxicity of pendimethalin.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.11
• /
• pp.2089-2092
• /
• 2007

Tantalum-containing metal oxides, well known for their efficiency in water splitting and H2 production, have never been used in visible light driven photodecomposition of H2S and H2 production. The present work is an attempt in this direction and investigates their efficiency. A mixed metal oxide, ZnFe2Ta2O9, with the inclusion of Fe2O3 to impart color, was prepared by the conventional ceramic route in single- and double-calcinations (represented as ZnFe2Ta2O9-SC and ZnFe2Ta2O9-DC respectively). The XRD characterization shows that both have identical patterns and reveals tetragonal structure to a major extent and a minor contribution of orthorhombic crystalline system. The UV-visible diffuse reflection spectra demonstrate the intense, coherent and wide absorption of visible light by both the catalysts, with absorption edge at 650 nm, giving rise to a band gap of 1.9 eV. Between the two catalysts, however, ZnFe2Ta2O9-DC has greater absorption in almost the entire wavelength region, which accounts for its strong brown coloration than ZnFe2Ta2O9-SC when viewed by the naked eye. In photocatalysis, both catalysts decompose H2S under visible light irradiation (λ ≥ 420 nm) and produce solar H2 at a much higher rate than previously reported catalysts. Nevertheless, ZnFe2Ta2O9-DC distinguishes itself from ZnFe2Ta2O9-SC by exhibiting a higher efficiency because of its greater light absorption. Altogether, the tantalum-containing mixed metal oxide proves its efficient catalytic role in H2S decomposition and H2 production process also.