Objective: Rice husk has attracted considerable attention in recent years due to its
chemical components that are beneficial for a wide range of applications. In this paper, silica
aerogel from Rice Husk Ash (RHA) was prepared through sol-gel processing and ambient
Methods: The silica RHA was extracted with sodium hydroxide solution to produce sodium
silicate solution and neutralized with sulphuric acid to form silica gel. Then, the silica aerogel
was further modified with an amine, 3-(aminopropyl) triethoxysilane (APTES), because
amine groups provide specific adsorption sides for CO2 adsorption. The functional group,
surface morphology, and elemental composition of rice husk, silica aerogel, and modified
silica aerogel were characterized by Fourier transform infrared spectroscopy (FTIR), Scanning
Electronic Microscopy (SEM) and Elemental Analysis (EA).
Results: For amine-modified silica aerogel, it was found that the sample consists of N-H
band at a certain peak. FTIR and SEM analysis revealed that the synthesized silica aerogel
has fibrous morphology and indicates a similar trend with previous researches. The aminemodified
silica aerogel (AMSA) is able to adsorb 0.88 mol CO2/kg AMSA.
Concluson: This study shows that the rice husk silica aerogel modified with APTES could
enhance the CO2 adsorption performance due to the physisorption and chemisorption.