Synthesis of very high surface area Au-SBA-15 materials by confinement of gold nanoparticles formation within silica pore walls

Abstract Very high surface area Au-SBA-15 type materials containing gold nanostructures were synthesised by oxidatively polymerizing aniline using chloroauric acid concurrently with condensing silicate in the presence of a triblock copolymer. The aforementioned synthesis resulted in significant changes to the morphology, texture, density and surface properties of the gold loaded materials as compared to SBA-15 prepared using a very similar method. The surface area of all of the prepared gold loaded materials was significantly higher than the parent SBA-15, with one material having an extremely high surface area that was more than double the parent SBA-15 (1424 m 2  g −1 vs 640 m 2  g −1 ). Characterisation of the gold loaded materials with small and wide angle X-ray diffraction, N 2 adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo gravimetric analysis (TGA), infrared spectroscopy (FTIR), and diffuse reflectance UV–vis spectroscopy revealed that the prepared gold containing SBA-15 materials were ordered and that they contained two distinct sizes of gold nanoparticles (∼40 nm and ∼3–5 nm). High resolution TEM images of prepared materials that had been etched using potassium hydroxide showed that the smaller gold nanoparticles were incorporated within the walls of the mesoporous silica.