With the increasing pollution of water bodies by herbicides, there is an urgent need to develop an efficient and environmentally friendly photocatalyst using natural light. In this work, we combine the organic heterojunction PBDB-T:BTTIC-TT with biochar to design a low-cost photocatalyst-adsorbent with a higher density of reaction site and reduce the aggregation of the organic catalysts. By tuning the thiophene side chains of the acceptor in organic heterojunction, the visible-light absorption can be enhanced ∼18 % for better catalytic efficiency. The ·O is verified to play a major role during the photocatalytic process, and the degradation pathway of 2,4,6-trichlorophenol to small carboxylic acids is also revealed. The broader natural light response with the good adsorption of the photocatalyst can effectively enhance the 2,4,6-trichlorophenol removal rate up to 97.4 % within 1 h, and the excellent adaptability over a wide pH range as well as the great stability during 15 catalytic cycles shows the practical applications in the treatment of water bodies with different levels of herbicide pollution.

中文翻译：

---

有机异质结与生物炭协同作为自然光下除草剂快速降解的催化位点

随着除草剂对水体的污染日益严重，迫切需要开发一种利用自然光的高效环保光催化剂。在这项工作中，我们将有机异质结PBDB-T:BTTIC-TT与生物炭结合起来，设计出一种具有更高反应位点密度的低成本光催化剂吸附剂，并减少了有机催化剂的聚集。通过调整有机异质结中受体的噻吩侧链，可见光吸收可以提高约18％，以获得更好的催化效率。证实·O在光催化过程中起主要作用，并且还揭示了2,4,6-三氯苯酚降解为小分子羧酸的途径。更宽的自然光响应加上光催化剂良好的吸附作用，可有效提高1小时内2,4,6-三氯苯酚的去除率高达97.4%，并且在较宽的pH范围内具有优异的适应性以及在15年内的良好稳定性。催化循环显示了在处理不同程度的除草剂污染的水体中的实际应用。