Photocatalytic glass-ceramics doped with metallic Ag, semiconductor AgBr, and hybrid metal-semiconductor Ag-AgBr nanostructures were synthesized low-temperature Na-Ag ion exchange. The spectral features of the nanostructures in the silicate glass matrix as well as their photocatalytic performance were studied in detail. Glass-ceramics containing hybrid metal-semiconductor nanostructures were shown to possess one order of magnitude higher photocatalytic activity compared to their counterparts with metallic and semiconductor nanostructures.
View Article and Find Full Text PDFNanostructure based on a dielectric grating (AlO), gasochromic oxide (WO) and catalyst (Pd) is proposed as a hydrogen sensor working at the room temperature. In the fabricated structure, the Pd catalyst film was as thin as 1 nm that allowed a significant decrease in the optical absorption. A high-Q guided-mode resonance was observed in a transmission spectrum at normal incidence and was utilized for hydrogen detection.
View Article and Find Full Text PDFSilver molecular clusters were synthesized in photo-thermo-refractive glasses using the Na+-Ag+ ion exchange technique followed by heat treatment. Comprehensive study of cluster emission reveals the presence of spectrally separated fluorescence and phosphorescence with nanosecond and microsecond lifetime. Co-doping of glasses with Eu3+ was shown to results in quenching of cluster luminescence caused by energy transfer.
View Article and Find Full Text PDFThe treatment of monodisperse carbon nanodots (MCNDs) with a combination of aqueous ammonia and hydrogen peroxide is found to result in a prominent enhancement of their fluorescence efficiency. Depending on the hydrogen peroxide concentration, an increase of the MCNDs quantum yield of up to seven-fold has been achieved. Considering the absence of prominent changes in fluorescence lifetime and fluorescence spectra upon the treatment it is suggested that the observed rise of fluorescence efficiency originates from additional formation of new isolated sp domains surrounded by defect sites.
View Article and Find Full Text PDFMonodisperse carbon nanodots (MCNDs) having an identical composition, structure, shape and size possess identical chemical and physical properties, making them highly promising for various technical and medical applications. Herein, we report a facile and effective route to obtain monodisperse carbon nanodots 3.5 ± 0.
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