Study of Bismuth-Containing Composites Based on Thermally Modified Porous Glass with Low Additions of P2O5 and Fluorine Ions by the Near Infrared Spectroscopy Method

Abstract

Bismuth-containing composite materials are synthesized by the impregnation of matrices of thermally modified porous glass in 0.5 M water solutions of bismuth nitrate followed by the heat treatment of the bismuth-containing composite material in a wide temperature range of 50 to 870°C. The samples which differ by the regime of the thermal modification of porous glass (PG) (120, 400, and 600°C, duration 1 or 2 h) and the temperature of the heat treatment are studied by the near infrared spectroscopy. Dehydroxylation and glass surface concentration with impurity boron atoms occur with the growth of the heat treatment temperature. Bands caused by the absorption of Bi⁺ ions, bismuth active centers associated with silicon, and Bi₄ and Bi₃ bismuth dimers are found.