Development of novel nanoabsorbents by amine functionalization of Fe3O4 with intermediate ascorbic acid coating for CO2 capture enhancement

Abstract

Novel nanoabsorbents are developed CO2 capture enhancement by functionalized magnetite nanoparticles in a water-based nanofluid system. The functionalization of magnetic nanoparticles was performed using different organic and inorganic reagents: (3-Aminopropyl) triethoxysilane (APTES), tetraethyl orthosilicate (TEOS), and L(+)-ascorbic acid (AA). The first coating used AA followed by a secondary shell of SiO2, and then amine functionalization via APTES, creating the amine-functionalized double-coated magnetite (Fe3O4 @AA@SiO2-NH2). The CO2 adsorption capacity of the synthesized material was enhanced by 11% at ambient pressure, compared with that of amine functionalization without AA (Fe3O4 @SiO2-NH2). To evaluate the absorption enhancement of Fe3O4 @AA@SiO2-NH2 at 25 °C, concentrations ranging from 0.1 to 0.4 wt% were compared with those of the base fluid (water). The highest enhancement of 59.2% was obtained at a concentration of 0.3 wt%. A cyclic performance evaluation showed that the initial absorption capacity was reduced by only 7%. Owing to its nanoabsorbent stability, significant CO2 absorption enhancement, and high recyclability, Fe3O4 @AA@SiO2-NH2 will be a milestone in physical liquid absorption systems for a carbon free environment.