Highly efficient removal of organic pollutants by ultrahigh-surface-area-ethynylbenzene-based conjugated microporous polymers via adsorption–photocatalysis synergy

Two types of conjugated microporous polymer photocatalysts inherently possessing a high surface area (up to 1265 m2 g−1) have been synthesized via Sonogashira–Hagihara cross-coupling polycondensation and applied for the removal of different organic contaminants (rhodamine B, phenol and tetracycline) via adsorption–photocatalysis synergy. The study on the photocatalytic performance and mechanism demonstrated that the specific surface areas and the backbone structures of the polymers had a great influence on the photocatalytic performances. A higher specific surface area and an increased adsorption efficiency for pollutants contributed to the enhanced photocatalytic activity. The optical and electrochemical characterization studies revealed that compared with its counterpart with a network structure, the linear polymer (based on 1,4-diethynylbenzene) showed a narrower band gap and a higher photogenerated charge separation efficiency due to its better extended conjugated system, which boosted its photocatalytic activity. The above features made the polymers exhibit superior adsorption-photocatalytic activity compared with the reported photocatalysts. This work highlights the potential of developing porous organic semiconductors as highly efficient photocatalysts for environmental remediation.