The effective and safe capture and storage of radioactive iodine (¹²⁹I or ¹³¹I) is of significant importance during nuclear waste storage and nuclear energy generation. Here we present detailed evidence of highly efficient and reversible iodine capture in hexaphenylbenzene-based conjugated microporous polymers (HCMPs), synthesized via Buchwald–Hartwig (BH) cross-coupling of a hexakis(4-bromophenyl)benzene (HBB) core and aryl diamine linkers. The HCMPs present moderate surface areas up to 430 m² g^–1, with narrow pore size distribution and uniform ultramicropore sizes of less than 1 nm. Porous properties are controlled by the strut lengths and rigidities of linkers, while porosity and uptake properties can be tuned by changing the oxidation state of the HCMPs. The presence of a high number of amine functional groups combined with microporosity provides the HCMPs with extremely high iodine affinity with uptake capacities up to 336 wt %, which is to the best of our knowledge the highest reported to date. Two ways to release the adsorbed iodine were explored: either slow release into ethanol or quick release upon heating (with a high degree of control). Spectral studies indicate that the combination of microporosity, amine functionality, and abundant π-electrons ensured well-defined host–guest interactions and controlled uptake of iodine. In addition, the HCMPs could be recycled while maintaining 90% iodine uptake capacity (up to 295%). We envisage wider application of these materials in the facile uptake and removal of unwanted oxidants from the environment.

Since discovered in 2007, conjugated microporous polymers (CMPs) have been developed for numerous applications including gas adsorption, sensing, organic and photoredox catalysis, energy storage, etc. While featuring abundant micropores, the structural rigidity derived from CMPs’ stable π‐conjugated skeleton leads to insolubility and thus poor processability, which severely limits their applicability, e.g., in CMP‐based devices. Hence, the development of CMPs whose structure can not only be controlled on the micro‐ but also on the macroscale have attracted tremendous interest. In conventional synthesis procedures, CMPs are obtained as powders, but in recent years various bottom‐up synthesis strategies have been developed, which yield CMPs as thin films on substrates or as hybrid materials, allowing to span length scales from individual conjugated monomers to micro‐/macrostructures. This review surveys recent advances on the construction of CMPs into macroscale structures, including membranes, films, aerogels, sponges, and other architectures. The focus is to describe the underlying fabrication techniques and the implications which follow from the macroscale morphologies, involving new chemistry and physics in such materials for applications like molecular separation/filtration/adsorption, energy storage and conversion, photothermal transformation, sensing, or catalysis.