Synthesis of Silica-Based Materials Using Bio-Residues through the Sol-Gel Technique

KARINE ZANOTTI; KATERINE IGAL; MARÍA BELEN COLOMBO MIGLIORERO; VÂNIA GOMES ZUIN; PATRICIA GRACIELA VÁZQUEZ

Sustainable Chemistry

Elsevier

Lugar: Amsterdam; Año: 2021 vol. 2 p. 670 - 685

2673-4079

Abstract: This study focused on the use of citrus bio-waste and obtention of silica-based materialsthrough the sol-gel technique for promoting a greener and more sustainable catalysis. The solgel method is a versatile synthesis route characterized by the low temperatures the materials aresynthesized in, which allows the incorporation of organic components. This method is carried out by acid or alkali hydrolysis combined with bio-waste, such as orange and lemon peels, generated as coproducts in the food processing industry. The main objective was to obtain silica-based materials from the precursor TEOS with different catalysts?acetic, citric and hydro-chloric acids and ammonium hydroxide?adding different percentages of lemon and orange peels in order to find the influence of bio-waste on acids/alkali precursor hydrolysis. This was to partially replace these catalysts for orange or lemon peels. The solids obtained were characterized with different techniques, such as SEM, FT-IR, potentiometric titration and XRD. SEM images were compared with pure silica obtained to contrast the morphology of the acidic and alkali hydrolysis. However, until now, few attempts have been made to highlight the renewability of reagents used in the synthesis or to incorporate bio-based catalytic processes on larger scales.