The novel biochar-based organic semiconductor toward broadband and direct radicals transfer enhanced photocatalytic...

Organic semiconductor materials manifest themselves as fascinating light absorbers and high-speed carrier transport for applications in photocatalytic degradation and solar energy harvesting. The essential challenges lie in harvesting the complex synthesis processes and poor recyclability. To this end, a synergistic deposition strategy utilizing organic semiconductor materials extracted from discarded solar cells and natural adsorbent biochar has been proposed to mitigate these two challenges. Specifically, by utilizing impregnation method, we successfully constructed the D-A heterojunction organic semiconductor photocatalytic materials on the surface of biochar. Organic photocatalytic materials, PCE10:PC₇₁BM, has the wide absorption spectrum within the range of 400-800 nm, which allows for the massive generation of electrons and holes for photoreactions under illumination. Hence, such catalyzer can completely remove Malachite Green at a concentration of 80 mg/L within 15 min under weaken light condition (30 mW/cm²) due to the utilization of light energy by the organic semiconductor material to generate a large number of radicals with strong redox properties (Such as h⁺/·OH/·O₂^-/¹O₂), which ultimately degrade the pollutants into non-toxic and harmless small molecules.