Synthesis of porous silica from wasted SiO2‐containing molding compounds

Abstract

AbstractMaterialsIn this study, we provided a simple method to extract the silicate species from the waste silica‐containing molding compounds from the semiconducting industry.MethodsRecycled sodium silicate solution was obtained from alkaline extraction of the silica fillers in the waste molding compounds and dried and redissolved in appropriate amount of water.ResultsPorous silica of high surface area (>500 m2g−1) and tunable pore size (1.5–5.0 nm) could be feasibly synthesized by using the recycled sodium silicate as silica source and nature‐friendly homopolymer polyethylene glycol (PEG) as an organic template. The pore size of the PEG‐templating silicas was made tunable by hydrothermal treatment at different pH.ConclusionTo reduce the emission of CO2 gas from the removal of the PEG template, porous silica with a large surface area has been prepared at a low PEG/sodium silicate weight ratio of 1/20.