Study on the Performance of Optical Lenses under High Fluxes of Solar Radiation

This work compares the performance of optical lenses made of silica glass or borosilicate glass (BK-7) when submitted to high-flux radiation emitted by a xenon arc lamp or provided by a high-concentration solar tower. Each irradiation test lasted for 60 min, with continuous monitoring of the radiation-flux incident on the lenses and the temperature generated in their vicinity. All silica glass lenses showed a good performance with both irradiation sources, xenon arc lamp and natural solar radiation, contrary to what was observed with the lenses made of borosilicate glass which fractured when irradiated with a xenon arc lamp. The negative behavior observed with the borosilicate lenses is attributed to the fact that the radiation spectrum of a xenon arc lamp contains certain wavelengths, in the near ultraviolet (UV) region, that are not present in the natural solar radiation spectrum at sea level.

Impact of phthalocyanine structure as photosensitizer for ZnO nanophotocatalyst under natural solar irradiation

Novel composites of zinc oxide (ZnO) and copper phthalocyanines (CuTriPc and CuPc) were synthesized as efficient natural solar light photocatalysts for the photodegradation of organic wastewater pollutants. Spectroscopic and analytical measurements confirmed that both bulky triazolo copper phthalocyanine (CuTriPc) and unsubstituted planer (CuPc) were successfully coupled with ZnOnanoparticles. The synthesized nanocomposites were investigated as natural solar radiation photocatalysts toward the photodegradation of methylene blue (MB) analogue dye. The prepared CuTriPc/ZnO nanocomposite was proven to be an efficient solar light photocatalyst compared to pure ZnO and the unsubstituted CuPc/ZnO.

INVESTIGATION OF INCREASING THE PHOTOCATALYTIC ACTIVITY OF TITANIUM DIOXIDE DUE TO THE USE OF TUNGSTEN (VI) OXIDE

The paper presents the results of experimental studies to determine the possibility of increasing the photocatalytic activity of titanium dioxide through the use of tungsten (VI) oxide, by testing the decomposition of rhodamine B as an organic pollutant in aqueous solutions under the influence of UV radiation, including in the visible spectrum. Industrial titanium dioxide of rutile modification and tungsten trioxide obtained by biological synthesis due to the use of the vital activity of thionic bacteria (Thiobacillus ferrooxidans) were used as photocatalysts. It was found that the dye concentration in a solution with a mixture of TiO2 and WO3 in a ratio of 1: 1 under the influence of natural solar radiation decreased by 85% after 28 days of study compared with 30% and 42% for solutions with pure WO3 and TiO2, respectively.