Facile One-step Dialysis Strategy for Preparation of Porous Silica Nanoparticles with Rough Surface

In this study, porous silica nanoparticles were fabricated in the absence of organic surfactant template at room temperature by a facile one-step dialysis method. By using a dialysis system comprising an ammonia solution as the dialysate, a series of porous silica nanoparticles with a rough surface (e.g., raspberry-like) were obtained by the initiation of a homogeneous ternary tetraethylsilicate-water-ethanol system with different ammonia solution concentrations. The specific surface area and pore volume of porous nanoparticles were regulated by changing the dialysate concentrations. N-2 adsorption-desorption measurements revealed that the porous silica nanoparticles owned both mesopores and micropores and exhibited a type IV isotherm, hence, these nanoparticles can be used as mesoporous silica nanoparticles (MSNs). The Au@MSN nanocomposite can be used as a catalyst for the typical reduction of 4-nitrophenol to 4-aminophenol by NaBH4 and exhibited excellent catalytic performance.