Solution-phase synthesis of two-dimensional silica nanosheets using soft templates and their applications in CO₂ capture

Abstract

The solution-phase synthesis of silica nanosheets with tunable thickness and textural properties is still a challenge. We have developed a robust protocol to synthesize silica nanosheets using lamellar micelles as soft templates in a water–cyclohexane solvent mixture. The synthesized silica nanosheets (∼3.7 nm) possess significantly improved textural properties, with as high as 1420 m² g⁻¹ surface area and 3.47 cm³ g⁻¹ pore volume. When functionalized with tetraethylenepentamine (TEPA) molecules using a physisorption method, the silica nanosheets showed a CO₂ working capture capacity of 3.8 mmol g⁻¹ at 75 °C with fast capture kinetics and good sorbent stability.