摘要 :
TiO2 (commercial-P25 and synthesized by sol-gel method) was surface modified with platinum ions or [Pt-3(CO)(6)](6)(2-) clusters to improve its photocatalytic activity. The physical properties of the synthesized photocatalysts wer...
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TiO2 (commercial-P25 and synthesized by sol-gel method) was surface modified with platinum ions or [Pt-3(CO)(6)](6)(2-) clusters to improve its photocatalytic activity. The physical properties of the synthesized photocatalysts were examined by transmission electron microscopy (TEM), X-ray diffraction (XRD), and Brunauer, Emmett and Teller adsorption (BET) methods. To characterize the absorption ability of visible light, the diffusion reflectance spectra (DRS) were recorded. The charge-carrier lifetimes in TiO2 after UV illumination were determined by microwave absorption experiments using the time-resolved microwave conductivity (TRMC) method. The photocatalyst activity was examined by degradation of exemplary aqueous phase pollutants, such as Rhodamine B and phenol. The impact of the adsorbates on the photocatalytic activity depends strongly on the titania precursor (commercial or synthesized), the irradiation wavelength (UV or visible), and the model compound (dye or phenol). The results show that it is possible to enhance the P25 photocatalytic activity under UV-visible light by doping it with Pt clusters. Also, P25 doping with Pt(II) or Pt clusters results in enhancement of the activity under visible light. Pt(IV)/TiO2 synthesized by sol-gel method exhibits better photoactivity under UV-visible and visible light compared to the unmodified titania. In all mentioned systems, a positive effect of modification with platinum clusters and, in particular, an important enhancement in photocatalytic activity under visible light were obtained. These results are explained by enhancement in visible light absorption and inhibition of charge-carrier recombination.
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摘要 :
Currently the prevalence of obesity and diabetes is increasing throughout the world. The unsatisfactory long-term results observed in the treatment of both are due to their complex pathophysiologies and the difficulties related to...
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Currently the prevalence of obesity and diabetes is increasing throughout the world. The unsatisfactory long-term results observed in the treatment of both are due to their complex pathophysiologies and the difficulties related to maintaining lifestyle changes. From the knowledge of the incretin effect and its alteration in patients with type 2 diabetes mellitus, GLP-1 receptor agonists arise, molecules with high structural homology with native GLP-1. Scientific evidence supports its use for the long-term treatment of diabetes, especially in the presence of associated cardiovascular and/or renal failure. In 2009, the use of liraglutide for patients with diabetes was approved in Europe, and in 2014 it was signed for the first time in the United States to treat obesity, since it was observed that the use of these drugs causes significant weight loss.
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