Construction of two-dimensional porphyrin-based fully conjugated microporous polymers as highly efficient photocatalysts

[Display omitted] •A series of porphyrin-based fully conjugated microporous polymers were synthesized.•The polymers could be used as photocatalysts under visible-light irradiation.•Fully π-conjugated networks enhance visible light-harvesting capability of MPor.•Polymers exhibit excellent photocatalytic capability, recyclability and stability.•The mechanism of the enhanced photocatalytic efficiency is discussed in detail. Conjugated polymers consist of extended π-conjugated systems, which are a new generation of heterogeneous photocatalysts. Herein, a series of two-dimensional fully conjugated microporous polymers (benzobisoxazole-linked porphyrin-based conjugated microporous polymers, BBO-Por-CMP and BBO-MPor-CMPs, M = Zn, Cu, Ni) were designed and synthesized by using porphyrins as building block and benzobisoxazoles as bridge linker for the first time. They have three highlighted advantages for photocatalytic application, namely robust, non-toxic, visible-light active, making them attractive photocatalyst candidates when integrating with their intrinsic features. BBO-Por-CMP and BBO-MPor-CMPs with fully π-conjugated and rigid microporous networks efficiently improve light-harvesting capability in the long-wavelength visible light region. The bridge linker benzobisoxazole efficiently prevents the aggregation of porphyrins, increases the exposure of the majority of the porphyrin units to oxygen, and enhances photocatalytic capability. As a result, oxidants-free BBO-Por-CMP and BBO-MPor-CMPs enable efficiently degradation of high concentrations (25 mg/L) and wide range of dyes (RB, MB, MO) in a short time. Therefore, BBO-Por-CMP and BBO-MPor-CMPs can be considered as promising photocatalysts for dealing with dyes sewage.