Optimizing Rice Husk Silica Mass and Sonication Time for a More Efficient and Environmentally Friendly Synthesis of SBA-15

Abstract

By optimizing rice husk silica mass and sonication time, SBA-15 was successfully synthesized in a more efficient and environmentally friendly way. The solution of Pluronic P-123 was mixed with the solution containing NaOH and various masses of rice husk silica (4–12 g), followed by sonication for a certain time (30–150 min). The mixture was filtered and washed with distilled water and ethanol until neutral, then dried at 110 °C for 2 h and calcined at 500 °C for 6 h. The results showed that the optimal mass of rice husk silica was 8 g, while the optimal sonication time was 30 min. The product has a cylindrical pore shape with good crystallinity and pore structure regularity. The specific surface area (SBET), the pore diameter (DBJH), the specific pore volume (VBJH), and the wall thickness (WT) of the product were 601 m2 g–1, 4.76 nm, 0.88 mL g–1, and 5.02 nm, respectively. These results are not considerably different from the porosity of SBA-15, synthesized previously using conventional hydrothermal techniques from various silica sources. In addition, it is also comparable to the porosity of SBA-15 produced from TEOS by sonochemical methods as well as with commercial SBA-15.