Preparation and characterization of hybrid SBA-15 mesoporous silica: A simple, robust and versatile sol-gel approach for experimenting with nanomaterials in university courses

Abstract

When conducting a university laboratory practice to introduce students to the world of nanomaterials and sol-gel synthesis, several important challenges arise. The primary ones lie in reconciling simplicity and resource efficiency with high educational value and the ability to perform a detailed analysis of the results. With this in mind, the study of SBA-15, a porous material based on SiO2, with low toxicity and cheap precursors, emerges as a versatile platform. As such it allows: 1. evaluating the impact of the sol-gel synthesis variables on the final morphology, 2. obtaining its hybrid derivative by taking advantage of well-known silicon chemistry and the extensive available library of organosilanes, and 3. studying the notable properties of these materials, such as their high specific surface area, tailored surface modification and adsorption capacity of ions or molecules. This work describes the activities carried out for the synthesis, functionalization, and characterization of SBA-15 mesoporous silica within the framework of the experimental practice of an intensive course for PhD students at the South American Sol-Gel School. Emphasis is placed on the time-optimized synthesis protocol and the various possible morphological and chemical characterization approaches. Additionally, the physicochemical and adsorption properties of cationic species of environmental interest are characterized.