Search results for "Sol–gel"
showing 2 items of 12 documents
centers induced by γ irradiation in sol–gel synthesized oxygen deficient amorphous silicon dioxide
2007
The effects of room temperature γ-ray irradiation up to a dose of ∼1300 kGy are investigated by Electron paramagnetic resonance (EPR) measurements in amorphous silicon dioxide (a-SiO2) produced by a sol-gel synthesis method that introduces O{triple bond, long}Si{single bond}Si{triple bond, long}O oxygen deficiency. We have found that exposure to radiation generates the Eγ′ center with the same spectral features found in high purity commercial a-SiO2. The maximum concentration of defects induced in this sol-gel material indicates that its resistance to radiation is comparable to that of synthetic fused a-SiO2. The concentration of Eγ′ center increases with irradiation, featuring a sublinear …
Effect of Urea–Hydrogen Peroxide Content on the Photocatalytic Activity of Zinc Oxide Nanoparticles
2021
ZnO nanoparticles (NPs) were synthesized using zinc acetate dihydrate, ethanol, and oxalic acid as precursor, solvent, and complexing agent, respectively, and urea–hydrogen peroxide (UHP) as, simultaneously, nitrogen precursor and oxygen donor. The structural, morphological, textural, and optical properties of ZnO photocatalysts were investigated using different characterization methods such as XRD, SEM, BET, and UV-Vis-DRS. The XRD patterns showed that the products consisted of ZnO and revealed the presence of nitrogen. SEM images revealed the agglomeration and aggregation of NPs. The photocatalytic activity of ZnO samples was estimated based on the photo-oxidation of 2-propanol under UV i…