Refernces
10.1002/jhet.2856
The research focuses on the eco-friendly synthesis and antioxidant activity of benzopyrano[2,3-d]pyrimidine derivatives, which are compounds known for their pharmacological and biological activities. The purpose of the study was to develop a cost-effective, environmentally benign method for synthesizing these derivatives using a three-component one-pot tandem approach. The researchers used salicylaldehydes, malononitrile, and secondary amines as starting materials, catalyzed by a TiO2–SiO2 catalyst under solvent-free conditions at 80°C. The methodology offered several advantages, including mild experimental conditions, reusability of the catalyst, and high product yields. The study concluded that the synthesized compounds, particularly those bearing a 2-OMe group on the hydroxyphenyl group (4g, 4h, and 4i), exhibited good antioxidant activity, as evidenced by NO, DPPH, FRAP, and H2O2 assays, and were comparable to ascorbic acid in their activity. The presence of the OCH3 group was identified as a significant factor contributing to the high antioxidant activity of these compounds.
10.1016/j.jcat.2017.07.017
The research investigates the synthesis, characterization, and photocatalytic properties of neodymium (Nd)-modified titanium dioxide (TiO2) nanoparticles prepared via the hydrothermal method. The study aims to enhance the visible light photocatalytic activity of TiO2 by doping it with Nd in the range of 0.1 to 1.0 mol%. The photocatalysts were characterized using various techniques, including diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), X-ray fluorescence (EDX), Brunauer–Emmett–Teller (BET) method, X-ray powder diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectroscopy (PL). The results showed that the Nd-modified TiO2 exhibited high photocatalytic activity under visible light, with the highest activity observed for the sample modified with 0.1 mol% Nd3+. This sample had a surface area of 124 m2/g and an average crystal size of 10.9 nm. The study also explored the excitation mechanism under visible light and concluded that the up-conversion process was not responsible for the degradation of phenol under visible light irradiation. The enhanced photocatalytic activity was attributed to the increased adsorption sites, BET surface area, decreased crystallite size, and prevention of electron-hole recombination.
Synthesis and characterization of anatase tio2 microspheres self-assembled by ultrathin nanosheets
10.3390/ma14112870
The research presents a novel method for synthesizing anatase TiO2 microspheres with a high percentage of (001) facets using potassium fluorotitanate as the sole reagent through a hydrothermal process. The study explores two synthesis methods: the on-site precipitation hydrothermal method and the drop-casting deposition method. The results indicate that the microspheres synthesized at 180–200 °C for 2 hours using the on-site precipitation hydrothermal method exhibit the best crystallinity, shape, and dimensions, with nearly 100% exposed (001) facets. The research highlights the significant effects of temperature and synthesis time on the morphology of the microspheres and anatase nanosheets. The findings suggest that these microspheres have great potential for applications in pollution prevention, environmental protection, and energy fields due to their excellent photocatalytic and photoelectric properties.
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