25 research outputs found

    A review of communication-oriented optical wireless systems

    Get PDF

    Investigation of Advanced Oxidation Process in the Presence of TiO<sub>2</sub> Semiconductor as Photocatalyst: Property, Principle, Kinetic Analysis, and Photocatalytic Activity

    No full text
    Water pollution is considered a serious threat to human life. An advanced oxidation process in the presence of semiconductor photocatalysts is a popular method for the effective decomposition of organic pollutants from wastewater. TiO2 nanoparticles are widely used as photocatalysts due to their low cost, chemical stability, environmental compatibility and significant efficiency. The aim of this study is to review the photocatalytic processes and their mechanism, reaction kinetics, optical and electrical properties of semiconductors and unique characteristics of titanium as the most widely used photocatalyst; and to compare the photocatalytic activity between different titania phases (anatase, rutile, and brookite) and between colorful and white TiO2 nanoparticles. Photocatalytic processes are based on the creation of electron–hole pairs. Therefore, increasing stability and separation of charge carriers could improve the photocatalytic activity. The synthesis method has a significant effect on the intensity of photocatalytic activity. The increase in the density of surface hydroxyls as well as the significant mobility of the electron–hole pairs in the anatase phase increases its photocatalytic activity compared to other phases. Electronic and structural changes lead to the synthesis of colored titania with different photocatalytic properties. Among colored titania materials, black TiO2 showed promising photocatalytic activity due to the formation of surface defects including oxygen vacancies, increasing the interaction with the light irradiation and the lifetime of photogenerated electron–hole pairs. Among non-metal elements, nitrogen doping could be effectively used to drive visible light-activated TiO2

    Investigation of Advanced Oxidation Process in the Presence of TiO2 Semiconductor as Photocatalyst: Property, Principle, Kinetic Analysis, and Photocatalytic Activity

    No full text
    Water pollution is considered a serious threat to human life. An advanced oxidation process in the presence of semiconductor photocatalysts is a popular method for the effective decomposition of organic pollutants from wastewater. TiO2 nanoparticles are widely used as photocatalysts due to their low cost, chemical stability, environmental compatibility and significant efficiency. The aim of this study is to review the photocatalytic processes and their mechanism, reaction kinetics, optical and electrical properties of semiconductors and unique characteristics of titanium as the most widely used photocatalyst; and to compare the photocatalytic activity between different titania phases (anatase, rutile, and brookite) and between colorful and white TiO2 nanoparticles. Photocatalytic processes are based on the creation of electron&ndash;hole pairs. Therefore, increasing stability and separation of charge carriers could improve the photocatalytic activity. The synthesis method has a significant effect on the intensity of photocatalytic activity. The increase in the density of surface hydroxyls as well as the significant mobility of the electron&ndash;hole pairs in the anatase phase increases its photocatalytic activity compared to other phases. Electronic and structural changes lead to the synthesis of colored titania with different photocatalytic properties. Among colored titania materials, black TiO2 showed promising photocatalytic activity due to the formation of surface defects including oxygen vacancies, increasing the interaction with the light irradiation and the lifetime of photogenerated electron&ndash;hole pairs. Among non-metal elements, nitrogen doping could be effectively used to drive visible light-activated TiO2

    Synthesis, receptor affinity and effect on pentylenetetrazole-induced seizure threshold of novel benzodiazepine analogues: 3-Substituted 5-(2-phenoxybenzyl)-4H-1,2,4-triazoles and 2-amino-5-(phenoxybenzyl)-1,3,4- oxadiazoles

    No full text
    The new series of 5-(2-phenoxybenzyl)-4H-1,2,4-triazoles, possessing C-3 thio, alkylthio and ethoxy substituents, and 2-amino-5-(2-phenoxybenzyl)-1,3,4- oxadiazoles were designed and synthesized as novel benzodiazepine analogues. Most of them revealed similar to superior binding affinity to the GABA A/benzodiazepine receptor complex, relative to diazepam as the reference drug. Among them, 5-(4-chloro-2-(2-fluorophenoxy)benzyl)-3-benzylthio- 4H-1,2,4-triazole (8l) showed the highest affinity (IC50 = 0.892 nM) relative to diazepam (IC50 = 2.857 nM) and also showed the most increase in pentylenetetrazole-induced seizure threshold relative to diazepam as the reference drug. © 2014 Elsevier Ltd. All rights reserved
    corecore