High toxic Cr(VI) has great harm to the environment and human body. The structural design of photocatalyst is an effective strategy to improve their photocatalytic activities. The Z-scheme heterojunction not only has excellent performance in the separation of photogenerated carriers, but also retains the strong redox ability of the catalyst. In this study, a dual Z-scheme Bi₂S₃-ZnS/MoSe₂ (BZM) photocatalyst with ZnS and Bi₂S₃ deposited on the surface of 2D MoSe₂ nanosheets is designed and prepared for the photocatalytic reduction of Cr(VI). The experimental results prove that BZM-0.15 shows the most excellent photocatalytic performance with the reduction efficiency of more than 95.4%, which is much higher than Bi₂S₃ (45.4%), ZnS (47.7%) and MoSe₂ (59.6%). Besides, BZM-0.15 also has good cycle stability. The Z-scheme heterojunction in Bi₂S₃-ZnS/MoSe₂ plays a vital role for enhancing the visible light absorption and efficiently promoting the photogenerated carriers transfer by providing double charge transfer channels. This research will offer a new method of designing and synthesizing a novel dual Z-scheme photocatalyst for effective photocatalytic reduction of Cr(VI).

高毒Cr(VI)对环境和人体有很大危害。光催化剂的结构设计是提高其光催化活性的有效策略。Z型异质结不仅在光生载流子分离方面具有优异的性能，而且还保留了催化剂强大的氧化还原能力。在这项研究中，一种双 Z 型 Bi ₂ S ₃ -ZnS/MoSe _{2 (BZM) 光催化剂在二维 MoSe 2}表面上沉积了 ZnS 和 Bi ₂ S ₃纳米片是为 Cr(VI) 的光催化还原而设计和制备的。实验结果证明BZM-0.15表现出最优异的光催化性能，还原效率超过95.4%，远高于Bi ₂ S ₃ (45.4%)、ZnS (47.7%)和MoSe ₂ (59.6%) . 此外，BZM-0.15还具有良好的循环稳定性。Bi ₂ S ₃ -ZnS/MoSe _{2中的Z型异质结}通过提供双电荷转移通道，对于增强可见光吸收和有效促进光生载流子转移起着至关重要的作用。本研究将为设计和合成新型双Z型光催化剂提供一种新方法，用于有效光催化还原Cr(VI)。