College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024, PR China.
Dalton Trans. 2023 Feb 21;52(8):2472-2484. doi: 10.1039/d2dt04030a.
Hierarchical micro/nanostructures assembled from nanorods and nanosheets have become promising candidates for photocatalysis. In this work, a series of hierarchical Cd-Ni-MOF micro/nanostructures, assembled from nanosheets and nanorods, were fabricated a two-step solvothermal process involving the partial replacement of Ni with Cd in the Ni-MOF-74 structure. Different morphologies were obtained by considering different volume ratios of DMF and ethanol as the solvent during synthesis. Hierarchical Cd-Ni-MOF-T/CdS/NiS hybrid micro/nanostructures were synthesized by Ni and Cd exchange of Cd-Ni-MOFs with S. The as-prepared samples, which were composed of thin nanosheets alone, exhibited the best photocatalytic H evolution rate of about 40.08 mmol g h. The p-n junction between CdS and NiS was found to be beneficial for the migration of photogenerated electrons from the conduction band (CB) of NiS to the CB of CdS. The heterojunction between CdS and Cd-Ni-MOF-T further promoted the transfer of an electron from the CB of CdS to the CB of Cd-Ni-MOF-T. Thus, this study demonstrated that hierarchical Cd-Ni-MOF-T/CdS/NiS architectures have a large specific surface area, leading to significantly improved photocatalytic activity.
由纳米棒和纳米片组装而成的分级微/纳结构已成为光催化的有前途的候选者。在这项工作中，通过两步溶剂热法制备了一系列由纳米片和纳米棒组装而成的分级 Cd-Ni-MOF 微/纳结构，该方法涉及在 Ni-MOF-74 结构中部分用 Cd 替代 Ni。通过考虑合成过程中 DMF 和乙醇的不同体积比作为溶剂，获得了不同的形貌。通过 Cd-Ni-MOF 与 S 的 Ni 和 Cd 交换合成了分级 Cd-Ni-MOF-T/CdS/NiS 杂化微/纳结构。所制备的样品由单独的薄纳米片组成，表现出约 40.08 mmol g h 的最佳光催化 H 2 演化率。发现 CdS 和 NiS 之间的 p-n 结有利于从 NiS 的导带 (CB) 向 CdS 的 CB 迁移光生电子。CdS 和 Cd-Ni-MOF-T 之间的异质结进一步促进了从 CdS 的 CB 到 Cd-Ni-MOF-T 的 CB 的电子转移。因此，这项研究表明，分级 Cd-Ni-MOF-T/CdS/NiS 结构具有大的比表面积，从而显著提高了光催化活性。
