Fabrication of high quality mesoporous silica/gold film nanocomposites: calcination versus thermal hydrogen reduction

Abstract

High quality mesoporous silica is an important nanomaterial in confinement of metal nanoparticles for potential applications as catalysts, sensors, and opto-electronic devices. Herein we report that high quality mesoporous silica/gold film nanocomposites with an interpore distance of 4.1 nm were successfully fabricated as transparent thin film by an amphiphilic trinuclear gold(I) pyrazolate complex that act as both a template in sol-gel synthesis and as a metal source in formation of gold nanoparticles (AuNPs). In contrast to the calcined thin films at 250 and 450C for 3 h, diffraction peak of d100 and transmission electron microscope (TEM) images showed high quality of mesoporous silica/gold film nanocomposites after thermal hydrogen reduction in the temperature range between 190 and 250C for 2 h. Nevertheless, both methods indicated formation of AuNPs as proved by the presence of diffraction peak at 2 = 38.20, surface plasmon resonance (SPR) peak between 500 to 580 nm, and spherical shape of TEM images.