Absence Of Organic Matrix Research Articles

Doped TiO2 Photocatalysts for the Photocatalytic Degradation Efficiency of Methylene Blue and Humic Acid under Solar Light

I n various advanced oxidation processes, photocatalysis is a promising and efficient way? to remove natural organic matter consisting of humic acids and fulvic acids. The principle of this method involves both usage of a semiconductor photocatalyst and O2 for the generation of radicals. Among them, TiO2 photocatalysis is the most popular and studied one since TiO has unique properties such as being chemically inert, photocatalytically stable, Phone: +90 386 280 3104cheap, non-toxic, environmentally benign and exhibiting high oxidative power. However, despite all the advantages of using TiO2 as a photocatalyst, there is a major disadvantage. Since TiO2 has a broad band gap, its usage widely under solar light is limited and only allows to be active under UV light. Doping is one of the most popular methods to enhance the photocatalytic activity of TiO2 via using metal or non-metal species as dopants. In this respect, solar light sensitive TiO2 photocatalyst, C, N, S, Se doped and S/N codoped TiO2 photocatalysts were synthesized by using wet-impregnation method. These doped photocatalysts were characterized by Raman spectroscopy to determine the crystal surface morphology. Moreover, methylene blue was used to investigate the photocatalytic performance of prepared doped TiO2 photocatalysts in the presence or absence of organic matrix. Photocatalytic experiments were performed using a solar light simulating photoreactor. Humic acid characterization was monitored by UV-vis and fluorescence spectroscopy

Total reflection x-ray fluorescence spectroscopy as a tool for evaluation of iron concentration in ferrofluids and yeast samples

In this study, total reflection x-ray fluorescent (TXRF) spectrometry was applied for the evaluation of iron concentration in ferrofluids and biological samples containing iron oxide magnetic nanoparticles obtained by the laser target evaporation technique. Suspensions of maghemite nanoparticles of different concentrations were used to estimate the limitation of the method for the evaluation of nanoparticle concentration in the range of 1–5000ppm in absence of organic matrix. Samples of single-cell yeasts grown in the nutrient media containing maghemite nanoparticles were used to study the nanoparticle absorption mechanism. The obtained results were analyzed in terms of applicability of TXRF for quantitative analysis in a wide range of iron oxide nanoparticle concentrations for biological samples and ferrofluids with a simple established protocol of specimen preparation.