Extraction, characterization, and catalytic potential of amorphous silica from corn cobs by sol-gel method

A simple method based on alkaline extraction followed by acid precipitation can be used to form silica aquagel from corn cob ash (CCA). SEM-EDS analysis confirmed the high silicon and oxygen content of the extracted silica. XRD diffraction indicated that the obtained product was amorphous silica, while FTIR data demonstrated the presence of siloxane and silanol groups. TEM images revealed the silica to be amorphous, and have an agglomeration form with an average diameter of ∼50 nm. CCA-extracted silica (0.1 g/20 ml) was observed to have good catalytic potential with 100% removal of 12 × 10−4 M methylene blue.