Microwave assisted synthesis of ErYbCaMoO nano-phosphor for efficient temperature sensing and catalytic applications.

Here, Er/Yb Co-doped CaMoO materials (ErYbCaMoO NPs where x = 0, 0.01 and y = 0, 0.05, 0.10, 0.15, 0.20) were prepared by microwave-assisted method and its pure-tetragonal structure were confirmed by X-ray diffraction spectra (XRD), Rietveld-refinement and Raman-vibrational spectra. The transmission-electron microscopy (TEM) study indicates the formation of nearly spherical shaped nanomaterial with average size of ~ 15 nm. Additionally, absorption and emission properties were studied by UV-Visible-NIR and photoluminescence (PL) spectrometer. The UV-Visible-NIR spectra attribute absorption of Er ion in visible region (380-700 nm) and absorption of Yb ion in near-infrared region (700-1400 nm). Moreover, PL up-conversion spectra of the sample recorded under excitation wavelength 980 nm. The PL peaks were observed at 530, 544-552, and 656-670 nm. Prominent PL-intensity was observed for ErYbCaMoO phosphor. Temperature dependent PL study reveals that present phosphor is robust phosphor for temperature sensor. In addition, Er/Yb doped CaMoO nanomaterials exhibited excellent activity and selectivity in the aerial oxidation of benzoin over benzyl under oxidant-free reaction conditions. The synergistic effect Er/Yb co-doing in CaMoO matrix was observed, where only CaMoO material found to be inactive towards above oxidation reaction. Moreover, the oxidation of primary benzyl-alcohols was furnished in presence of tertiary butyl hydroperoxideas oxidant.