<p>The design of catalysts with hierarchical architectures and phase interfaces is crucial for enhancing active site accessibility and catalytic efficiency. In this work, a recyclable nanocatalyst based on Sm₂CoMnO₆ nanoparticles embedded in dendritic fibrous nanosilica (DFNS) was developed using a green and straightforward synthetic strategy. A deep eutectic solvent assisted method was employed to fabricate DFNS with high surface area and a threadlike, dandelion like morphology composed of ultrathin 3D nanosheets and mesoscopic cavities. The large specific surface area originates from the material’s three dimensional hierarchical architecture, which consists of interconnected two dimensional ultrathin layers featuring mesoporous voids. Sm₂CoMnO₆ nanoparticles were successfully incorporated onto DFNS through a simple and efficient synthesis procedure. This environmentally friendly synthesis route avoided the use of toxic solvents or hazardous reagents and utilized natural epoxides as renewable feedstocks. The resulting Sm₂CoMnO₆ DFNS nanocatalyst demonstrated high efficiency in the synthesizing biopolymers and polymers through the reaction of CO₂ with oxetane, epoxide, or limonene epoxide under mild conditions with excellent conversion and selectivity. These findings highlight the dual potential of this nanocatalyst platform for CO₂ fixation and green polymer synthesis, paving the way for integrated carbon capture and material production strategies.</p> Graphical Abstract <p></p>