Topology-Directed Synthesis of Macroscopic Perylene-Silsesquioxane Polymeric Aerogels: Overcoming Aggregation-Caused Quenching for Dual-Action Water Remediation.
Abstract
The persistent toxicity of phenolic contaminants necessitates the development of integrated water remediation technologies. While the synergistic "trap-and-destroy" pathway-combining rapid adsorption with in-situ photocatalytic degradation-is highly promising, its practical deployment is often hindered by the aggregation-caused quenching (ACQ) of organic chromophores and the recovery challenges associated with suspended powder catalysts. This work proposes a topology-directed engineering strategy to fabricate a macroscopic, metal-free material (PCSOA) by crosslinking perylene diimides with rigid polyhedral oligomeric silsesquioxane (POSS or SQs) cages. DFT calculations suggest that the rigid POSS nodes provide strong structural constraint to restrict the molecular motion of the photoactive perylene units, thereby suppressing non-radiative decay pathways while largely preserving the intrinsic frontier molecular orbitals. Driven by strong electrostatic and π-π affinities, the highly polarized network captures trinitrophenol with an uptake reaching 929 mg g-1. By gathering target molecules directly around the active sites, this localized accumulation significantly enhances visible-light photoactivity. Consequently, the system delivers a phenol mineralization rate constant of 1.79 h- 1 and removes over 98% of the total organic carbon (TOC). From a practical standpoint, formatting the material into a macroscopic aerogel bypasses the cumbersome separation steps inherent to powders, allowing for stable and high-throughput water treatment in continuous-flow setups.