Monolithic germanium oxide aerogel with the building block of nano-crystals

Abstract In the present paper, we have prepared germanium oxide aerogel using the sol–gel method followed by CO 2 supercritical drying. Scanning electron microscopy showed a fine microstructure of the as-prepared aerogel. Results from the nitrogen adsorption and desorption data exhibited that the aerogel had attractive specific surface area and typical pore size distribution of aerogel. X-ray diffraction indicated that the aerogel was composed of nano-crystals with hexagonal structure. X-ray photoelectron spectroscopy confirmed the existence of oxygen vacancies. At room temperature, interesting strong blue luminescence was observed at 425 nm under excitation wavelength at 280 nm. We proposed an explanation for the phenomenon.