RICE HUSK – AGRICULTURE WASTE AS RAW MATERIAL FOR SBA-15 MESOPOROUS SILICA

The obtaining of molecular sieves using alternative sources of silica represents a promising approach for replacing the conventional expensive silica sources, such as tetraethyl orthosilicate. These new raw materials with low costs can be agriculture wastes, such as barley husks, rice husks, wheat straws, or wheat husks. Therefore, the synthesis of silica nanomaterials using rice husk ash has been the focus of various studies, considering also the ecological, economic, and environmental issues. SBA-15 is a mesoporous silica sieve having uniform hexagonal pores with narrow pore size distribution and tuneable pore diameter, between 5 and 15 nm. Typical SBA-15 presents high surface area, increased thermal and mechanical stability, and is not harmful to the environment. Consequently, it represents well-suited material for different applications, such as adsorption and separation, support material for catalysts, or template to produce ordered mesoporous carbon. Considering all the above-mentioned details, this study reports the preparation of SBA-15 type mesoporous silica using rice husk ash as silica source, followed by a hydrothermal method. The morpho-structural properties of mesoporous silica were elucidated using various techniques, proving that the resulted mesoporous silica had typical features of SBA-15 molecular sieve, but with lower specific area (around 140 m2/g) and pore volume (0.240 cm3/g) than the one obtained from commercial sources.