Halogenated benzothiadiazole-based conjugated polymers as efficient photocatalysts for dye degradation and oxidative coupling of benzylamines

Donor-acceptor (D-A) conjugated polymers are widely used in photovoltaic applications and heterogeneous catalysis due to their tunable building block and pre-designable structures. Here, a series of adjustable Donor-acceptor (D-A) benzothiodiazole-based conjugated polymers were designed and synthesized. The photocatalytic performance could be improved by fine-tuning the chemical structure by halogen substitution (F or Cl). The polymers exhibited excellent optoelectronic properties and were effective photocatalysts for the degradation of RhB and MO dyes, as well as promoting the oxidative coupling of benzylamines. Complete degradation of RhB and MO occurred in 30 min under visible light radiation, while the yield of benzylamine coupling mediated by superoxide anion was as high as 82%. Systematic characterization methods were used to gain insights on the unique photocatalytic performance of the polymers. Our findings provide further insights into the design and synthesis of benzothiadiazole-based conjugated polymers as promising organic photocatalysts for solar energy conversion.