Constructing effective photocatalysts with visible light response to achieve rapid dehalogenation of polyhalogenated compounds remains a challenge nowadays. Herein, Pd nanoclusters-decorated TiO₂ nanosheets with surface defects (Pd/TNS) are designed for polyhalogenated biphenyls dehalogenation under visible light. Pd/TNS is able to rapidly remove bromine atoms of 4-bromobiphenyl in 30 min. Experimental results reveal that oxygen vacancies and Ti³⁺ are in-situ generated in TNS during Pd photodeposition, which extend the absorption band edge of Pd/TNS to visible light region. Besides, the unique two-dimensional nanosheets structure of TNS contributes to a high surface area for high dispersion of Pd nanoclusters. Importantly, the Pd nanoclusters serve to activate carbon-halogen bond in polyhalogenated biphenyls and hydrogen-oxygen in H₂O. The high dehalogenation efficiency could be assigned to a strong chemical interaction and synergistic effect between the Pd nanoclusters and TiO₂(B) nanosheets. Finally, a collaborative mechanism is proposed for photocatalytic dehalogenation of polyhalogenated biphenyls on Pd/TNS.

如今，构建具有可见光响应的有效光催化剂以实现多卤代化合物的快速脱卤仍然是一个挑战。本文中，设计了具有表面缺陷（Pd / TNS）的Pd纳米簇修饰的TiO ₂纳米片，用于可见光下的多卤代联苯脱卤。Pd / TNS能够在30分钟内快速去除4-溴联苯的溴原子。实验结果表明，氧空位和Ti ³⁺在Pd光沉积过程中，它们是在TNS中原位生成的，从而将Pd / TNS的吸收带边缘扩展到可见光区域。此外，TNS独特的二维纳米片结构有助于提高Pd纳米团簇的高表面积。重要的是，Pd纳米团簇可激活多卤代联苯中的碳-卤素键和H ₂ O中的氢氧。高脱卤效率可归因于Pd纳米团簇与TiO ₂（B）纳米片之间的强化学相互作用和协同效应。最后，提出了一种协同机制，用于在Pd / TNS上对多卤代联苯进行光催化脱卤。