Regulating the growth process of FAU zeolite via quantum dots for enhanced CO2/N2 separation

Abstract

Advances in carbon capture and storage (CCS) technologies are critical for mitigating global climate change due to their low cost and operational simplicity. Although zeolites hold promise for carbon capture, the development of advanced zeolite materials with optimized CO₂ separation efficiency and diffusivity remains challenging. In this study, we present a quantum dot-regulated growth strategy, in which silicon quantum dots (SiQDs) act as heterogeneous seeds to not only initiate the growth of nanoscale zeolite units but also guide their assembly. The resulting 13X-SiQDs exhibit a distinct micrometer-scale hollow sphere structure composed of nanoscale zeolite units, which provide additional adsorption sites and mesopores, significantly enhancing adsorption and diffusion. The amino groups on the surface of the SiQDs further enable chemical adsorption with CO₂, strengthening the binding force. The synergistic combination of thermodynamic and kinetic advantages enables 13X-SiQDs to achieve substantial improvements in CO₂ adsorption capacity (132.20 cm³·g⁻¹), CO₂/N₂ selectivity (561), and diffusion rate. This quantum dot-regulated synthesis strategy offers a promising approach for designing advanced adsorption materials with high performance, extending their potential applications beyond carbon capture.