Investigation on existing states and photoluminescence property of silver in the SiO2 three-dimensionally ordered macroporous materials

Abstract

The photoluminescence properties of silver species, including Ag⁺, Ag⁺–Ag⁺, Ag⁰, and Ag nanoparticles in various matrices, such as gel and glass have been extensively reported. In the present study, we present the preparation of silver including SiO₂ three-dimensionally ordered macroporous (3DOM) materials and investigate the existing states and photoluminescence property of silver in the SiO₂ 3DOM materials. The results show that only Ag⁺ ions exist in the SiO₂ 3DOM materials sintered at temperature below 400 °C. With the increasing sintering temperature, the Ag⁺ ions gradually transform into Ag⁺–Ag⁺, where simultaneously, a part of Ag⁺–Ag⁺ transform into Ag nanoparticles. The Ag⁺–Ag⁺ and Ag nanoparticles are formed in the SiO₂ 3DOM materials sintered at temperature from 450 to 650 °C. Finally, only Ag nanoparticles occur in the SiO₂ 3DOM materials prepared at 750 °C. The formation mechanisms of Ag species were discussed in the SiO₂ 3DOM materials.