The utilization of bagasse fly ash for mesoporous silica synthesis

Natural silica sources such as from biomass ashes provide an alternative cheap silica precursor for synthesizing advanced materials. Mostly, the silica content in the biomass is in the form of amorphous structure which is suitable to be used directly into the material formation. Bagasse fly ash (BFA) contains carbon and silica in a significant amount. The silica content can be recovered by a simple NaOH fusion method followed by water dilution to produce sodium silicate solution. Then, the obtained solution can be used for various material preparations such as zeolites and mesoporous silica materials. It was observed that the alkaline dissolution method is not only extracting silica but also other content such as Alumina and trace metals. Two different type of mesoporous silica, MCM-41 and SBA-15, have been synthesized by incorporating suitable template and sol-gel hydrothermal method using extracted silica source. The synthesized materials were characterized using TEM and XRD to confirm the morphology and crystal structure. Gas adsorption experiment of n-hexane has been done to examine the adsorption behaviour of the two prepared mesoporous silica. The results suggest that low cost natural silica sources can be an alternative for advanced material preparation. © Published under licence by IOP Publishing Ltd.