Sodium alginate-silica composite aerogels from rice husk ash for efficient absorption of organic pollutants

Sodium alginate-silica (SAS) composite aerogels with excellent absorption capacity were synthesized from rice husk ash through a sol-gel process and freeze drying. The physical and chemical properties of the SAS aerogels were fully characterized using field emission scanning electron microscopy, N-2 adsorption-desorption isotherms, thermogravimetric analysis, Fourier transform infrared spectroscopy, and other techniques. The silica-based composite aerogel containing 18% sodium alginate (18-SAS) had the largest specific surface area of 205.1 m(2) g(-1), the highest pore volume of 0.953 cm(3) g(-1), and the maximum organic-solvent absorption capacity of 6-14 g g(-1). Such an environmentally friendly, low-cost aerogel material with excellent performance is a promising candidate for organic-pollutant absorption.