Synthesis of Praseodymium-Doped GeO₂ Aerogels by Impregnation

A simple method for the preparation of doped GeO₂ aerogels is proposed. At the first stage, a gel with a composition of (NH₄)₃H(Ge₇O₁₆)(H₂O)_x was obtained by dissolving germanium dioxide in aqueous ammonia with pH 8.2. The dopant ions were introduced by impregnating the hydrogels with a dimethyl sulfoxide (DMSO) solution of praseodymium nitrate. The optimum conditions of the synthesis were determined, which allow uniform distribution of the dopant ion in the matrix. The Pr/Ge ratio in the resulting aerogels was 0.1. The aerogel samples were characterized in detail by IR, inductively coupled plasma-atomic emission spectroscopy (ICP-AES), low-temperature nitrogen adsorption, etc. It was found that praseodymium affects the luminescence characteristics of GeO₂ aerogels during excitation radiation with a wavelength of 240, 255, and 390 nm.