Role of pH in Modulating the Physicochemical Properties of Erbium-doped MoO3/SiO2 Nanoparticles

Molybdenum trioxide (MoO3) coated with SiO2 layered nanoparticles were prepared using Stober process by wet chemical method with pH adjusted to 9, 10 and 11. The physicochemical properties of Er:MoO3/SiO2, such as phase confirmation, quantum confinement, surface morphology, and shape were investigated by X-ray diffraction analysis, field emission scanning electron microscopy, Raman spectroscopy, FTIR and photoluminescence spectroscopy. The vibrational behaviour of chemical bonds was analyzed by Fourier transform infrared spectroscopy. The non-stoichiometric composition and the variation in composition of as prepared samples as well as rare earth ion-doped samples were confirmed by energy dispersive X-ray analysis. The optical behaviour of the defect-related emissions varied with pH and doping with the luminescent rare earth element erbium, further illustrated the tunable nature of the optical response. This work emphasizes upconverting properties of Er-doped MoO3/SiO2 nanoparticles for versatile applications.