Quantum dots (QDs) derived from two-dimensional (2D) nanosheets (NSs), especially ultrathin transition metal dichalcogenide (TMD, e.g. WS₂, WSe₂, MoS₂, MoSe₂) NSs, have attracted great attention due to their broad band absorption and high charge mobility. Herein, WS₂ QDs, one of the emerging extraordinary zero-dimensional (0D) TMD materials, were applied to the preparation of novel 0D/2D heterojunctions of WS₂ QDs/BiOCl nanosheets. The obtained WS₂/BiOCl composites exhibited significantly enhanced visible-light-driven photocatalytic activity as compared with pure BiOCl. The results indicated that the holes (h⁺) and O₂˙⁻ are the main active species generated by the catalysts under visible light irradiation. The enhanced photocatalytic performance could be due to the broad band absorption and up-conversion properties of the WS₂ QDs as well as the band alignment and the strong coupling between the WS₂ QDs and BiOCl NSs, leading to a broadened light absorption range and enhanced efficiency for electron–hole pair production and separation. These findings offer exciting opportunities using the extraordinary 2D TMD material-derived quantum dots for the fabrication of novel 0D/2D composites and may provide new insights into the application of the novel 0D/2D composites in catalysis.

中文翻译：

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结合BiOCl纳米片的 WS ₂量子点增强的可见光驱动的光催化作用：协同效应和机理研究†

源自二维（2D）纳米片（NSs）的量子点（QDs），尤其是超薄过渡金属二硫化碳（TMD，例如WS ₂，WSe ₂，MoS ₂，MoSe ₂）NSs，由于其宽带性而备受关注吸收和高电荷迁移率。在这里，WS ₂ QDs，一种新兴的非凡零维（0D）TMD材料之一，被用于制备WS ₂ QDs / BiOCl纳米片的新型0D / 2D异质结。与纯BiOCl相比，所获得的WS ₂ / BiOCl复合物表现出显着增强的可见光驱动的光催化活性。结果表明，孔（h ⁺）和O ₂ ˙ ^-是通过可见光照射下的催化剂中产生的主要的活性物质。增强的光催化性能可能归因于WS ₂ QD的宽带吸收和上转换特性，以及WS ₂ QD与BiOCl NS之间的能带排列和强耦合，从而导致了更宽的光吸收范围并增强了电子-空穴对生产和分离的效率。这些发现提供了使用非常规2D TMD材料衍生的量子点制造新颖的0D / 2D复合材料的令人兴奋的机会，并且可能为新颖的0D / 2D复合材料在催化中的应用提供新的见解。