Multidimensional carbon-based polymer/Bi₂O₂CO₃ S-scheme heterojunction boosting carrier separation in efficient photocatalytic seawater purification

Photocatalytic decomposition of seawater pollutants using solar energy as driving force has far-reaching significance. Herein, the multidimensional carbon-based polymer/Bi₂O₂CO₃ (BOC) S-scheme heterojunction, including: 2D graphitic carbon nitride/3D peony flower-like BOC composite and 0D carbon polymer dots/2D ultra-thin BOC nanosheets composite, were successfully constructed. Under light excitation, the photogenerated electrons of BOC recombine with the holes of the carbon-based polymer via S-scheme heterojunction, effectively maintaining the high redox properties of the photogenerated electrons for carbon-based polymer and the holes for BOC. The 1 wt% CPDs/BOC shows the best photocatalytic performance, with a homemade wastewater treatment device, heavily polluted (20 L of 100 mg/L RhB) seawater can be purified with only 5 hours of sunlight exposure. Meanwhile, the toxicology of intermediate products during the photocatalytic degradation process was analyzed in detail. Using the purified solution to cultivate bean sprouts found that the development of bean sprouts was not inhibited. © 2024 Elsevier B.V.