Functional Nanoboxes

Abstract

In this work, the preparation of mesoporous silica nanoboxes is presented for application in optical thin films. Mesoporous silica nanoboxes are obtained by coating cuprous oxide nanocubes with MCM-41 silica and subsequently dissolving the core. The thickness of the shell can be controlled by varying the silica precursor concentration. The surface area and pore size are quantified using N2 absorption. Filling the hollow particles with functional material, allows the boxes to become functional, without changing their colloidal stability. Two approaches were attempted to produce functional nanocubes. The seeded growth of gold nanoparticles proved to be problematic, as nucleating occurs randomly on the most favorable positions. Gold deposits were found on the outside of the wall and in the mesopores. Transformation of the Cu2O core into functional materials proved to result in well-defined particles. The cuprous oxide template was transformed to a copper core via “in liquid thermolysis”. Subsequently, the copper core was transformed into a silver or a gold core via galvanic displacement. The functionality of the silver core is confirmed by following the catalytic degradation of congo red dye via UV-Vis over time.