Preparation and Characterization of Nanozeolite NaA from Rice Husk at Room Temperature without Organic Additives

Abstract

Nanozeolite NaA was synthesized by the hydrothermal method with silica extracted from rice husk as silica source. Amorphous silica with 87.988 wt% <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mtext>SiO</mml:mtext><mml:mn>2</mml:mn></mml:msub></mml:math>was extracted from rice husk ash by a suitable alkali solution. The effect of the crystallization time and the ratio of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mtext>Na</mml:mtext><mml:mn>2</mml:mn></mml:msub><mml:mtext>O</mml:mtext><mml:mo>/</mml:mo><mml:msub><mml:mtext>SiO</mml:mtext><mml:mn>2</mml:mn></mml:msub></mml:math>on the properties of the final product was investigated. The synthesized nanozeolite was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) techniques, and Brunauer-Emmett-Teller (BET) method. Results revealed that the crystallization time and alkalinity have significant effects on the structural properties of nanozeolite. Nanocrystals NaA with crystal sizes ranging from 50 to 120 nm were synthesized at room temperature with 3 days aging, without adding any organic additives.