Heterogeneous iron-doped covalent triazine framework for the efficient photocatalytic upcycling of polystyrene waste to valuable aromatics under ambient conditions
File(s)
Supporting information
Published version
Author(s)
Type
Journal Article
Abstract
Polystyrene (PS), a widely used commodity plastic, has a persistently low recycling rate, making it a major contributor to plastic pollution. Selective PS upcycling under ambient conditions remains challenging due to its chemically inert structure, characterized by stable Csingle bondC and Csingle bondH bonds. As a consequence, efficient PS degradation typically requires energy-intensive pyrolysis or harsh oxidizing conditions. Existing homogeneous photocatalysts, such as strong acids or metal salts, are unsustainable long-term solutions for PS waste management due to their lack of reusability and complex separation requirements. Although covalent organic frameworks (COFs) and covalent triazine frameworks (CTFs) have previously been explored as general photocatalysts, their use in selective PS upcycling remains underexplored. Here, we report an iron-doped CTF for the efficient photocatalytic upcycling of PS under ambient conditions. By harnessing the framework's porous character and tunable electronic and photophysical properties, the catalyst incorporates less than 3 wt% iron and offers a sustainable alternative to photocatalysts with higher metal content. Synthesized via solvent-free mechanochemical Friedel-Crafts alkylation of trichlorotriazine and phenothiazine, the CTF forms a porous, p-type semiconductor with FeCl4− ions cross-linking 2D CTF polymer sheets to form an [FeCl4]@CTF heterogeneous photocatalyst. The disclosed [FeCl4]@CTF photocatalyst achieves 100% degradation of commercial and post-consumer PS under ambient conditions, yielding approximately 70% of valuable aromatic compounds with high selectivity. The scalable mechanochemical synthesis of the CTF, coupled with its reduced reliance on high metal loadings provides a sustainable blueprint for organocatalyst-driven plastic waste management using earth-abundant metals.
Date Issued
2026-06-01
Date Acceptance
2026-03-07
Citation
Chemical Engineering Journal, 2026, 537
ISSN
1385-8947
Publisher
Elsevier BV
Journal / Book Title
Chemical Engineering Journal
Volume
537
Copyright Statement
2026 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by- nc/4.0/).
License URL
Identifier
10.1016/j.cej.2026.175007
Publication Status
Published
Article Number
175007
Date Publish Online
2026-03-09