Enhancement of photodegradation efficiency, photoluminescence quantum yield, and magnetization in highly Yb3+-doped CdO nanoparticles synthesized via sol-gel method

Cd1-xYbxO (x = 0, 1, 5, 10, 15mol%) nanoparticles (NPs) were successfully synthesized by pulverizing the product obtained from a sol-gel process. The crystalline structure of the synthesized samples was established by X-ray diffraction analysis. Scanning electron microscopy revealed that the prepared samples were nanoscale and the size of the NPs decreased with increasing dopant concentration. Elemental analysis of the products was carried out by energy-dispersive X-ray spectroscopy. Ultraviolet-visible (UV-Vis) and Fourier-transform infrared (FT-IR) spectroscopies were used to characterize the synthesized species. Increasing the Yb3+ ion level in the hostmatter resulted indecreased bandgapenergy. Photoluminescence measurements confirmed the enhanced intensity of the characteristic emissionsin the Yb3+-doped CdO NPs, indicating appropriate substitution of Cd2+ with Yb3+ ions. Magnetic measurements revealed that, with addition of Yb3+ ion, the magnetic behavior of the samples changed. Increasing the dopant ion concentration, thereby decreasing the size of the obtained NPs, changed their behavior from paramagnetic to superparamagnetic, with increased saturation magnetization (M-S) for higher dopant level. Photocatalytic measurements under UV and natural sunlight irradiation revealed that the samples prepared with high dopant concentration (15 mol%) exhibited excellent photocatalytic activity under natural sunlight for decomposition of methylene blue dye.