Zn Doping Induced Band Gap Widening of Ag2O Nanoparticles

The present investigation widens the narrow bandgap of Ag2O to make it a semiconductor with more attractive properties. A typical hydrothermal synthesis procedure was used to prepare Zn doped Ag2O nanoparticles. The X-ray diffraction analysis of the prepared powder samples showed that the lattice parameters of Ag2O increase with doping, indicating the occupation of interstitial positions by the dopant atoms. Density functional theory calculations also demonstrated the expansion of the Ag2O crystal lattice with the dopant at an interstitial location. The bandgap of the Ag2O increases to 1.65 eV for 5-mole percent doping. The doped Ag2O nanoparticles photocatalytically degrade methyl orange under aerobic visible light conditions. It appears that the rise in the percentage of higher valence Zn doping converts the originally p-type to an n-type semiconductor.</p

Development of magnetically recyclable visible light photocatalysts for hydrogen peroxide production

The development of magnetically recyclable photocatalysts for economic and green H2O2 synthesis from water and oxygen only is virtually unexplored. Magnetic recyclability makes possible cost-effective laboratory or industrial reuse of the catalyst. The present research shows that magnetically recyclable starch functionalized Fe3O4/Ag/Ag2O superparamagnetic nanocomposites are very good visible light photocatalysts for H2O2 formation. These nanocomposites were prepared by precipitating Ag/Ag2O fine-sized nanostructures on starch functionalized magnetite nanoparticles (SMNPs). HR-TEM, XRD, and XPS analysis results showed the formation of SMNPs dotted with fine-sized Ag/Ag2O nanostructures smaller than their quantum confinement regimes. A p-n heterojunction is formed between (n-type) starch functionalized magnetite and (p-type) Ag2O components. Enhanced charge separation and the presence of plasmonic Ag nanostructures on the SM component cause efficient oxygen reduction with high H2O2 formation rates