Farrag Mostafa
Chemistry Department, Faculty of Science, Assiut University, Assiut, 71516, Egypt.
Sci Rep. 2023 Oct 17;13(1):17634. doi: 10.1038/s41598-023-44819-8.
For the first time, covalently anchoring size selected silver nanoclusters [Ag(MNBA)] on the BiS@UiO-66-NH and MoS@UiO-66-NH heterojunctions were constructed as novel photocatalysts for photodegradation of methylene blue (MB) dye. The anchoring of Ag on MoS@UiO-66-NH and BiS@UiO-66-NH heterojunctions extended the light absorption of UiO-66-NH to the visible region and improved the transfer and separation of photogenerated charge carriers through the heterojunctions with a unique band gap structure. The UV-Vis-NIR diffuse reflectance spectroscopic analysis confirmed that the optical absorption properties of the UiO-66-NH were shifted from the UV region at 379 nm to the visible region at ~ 705 nm after its doping with BiS nanorods and Ag nanoclusters (BiS@UiO-66-NH-S-Ag). The prepared BiS@UiO-66-NH-S-Ag and MoS@UiO-66-NH-S-Ag photocatalysts exhibited exceptional photocatalytic activity for visible light degradation of MB dye. The photocatalysts exhibited complete decolorization of the MB solution (50 ppm) within 90 and 120 min stirring under visible light irradiation, respectively. The supper photocatalytic performance and recycling efficiency of the prepared photocatalysts attributed to the covalent anchoring of the ultra-small silver clusters (Ag) on the heterojunctions surface. The X-ray photoelectron spectroscopic analysis confirmed the charge of the silver clusters is zero. The disappearance of the N-H bending vibration peak of primary amines in the FTIR analysis of BiS@UiO-66-NH-S-Ag confirmed the covalent anchoring of the protected silver nanoclusters on the UiO-66-NH surface via the condensation reaction. The BiS@UiO-66-NH-S-Ag catalyst exhibited excellent recyclability efficiency more than five cycles without significant loss in activity, indicating their good potential for industrial applications. The texture properties, crystallinity, phase composition, particle size, and structural morphology of the prepared photocatalysts were investigated using adsorption-desorption N isotherms, X-ray diffraction (XRD), HR-TEM, and FE-SEM, respectively.
首次将尺寸选择的银纳米团簇[Ag(MNBA)]共价锚定在BiS@UiO-66-NH和MoS@UiO-66-NH异质结上，构建了用于光降解亚甲基蓝(MB)染料的新型光催化剂。Ag锚定在MoS@UiO-66-NH和BiS@UiO-66-NH异质结上，将UiO-66-NH的光吸收扩展到可见光区域，并通过具有独特带隙结构的异质结改善了光生电荷载流子的转移和分离。紫外-可见-近红外漫反射光谱分析证实，在UiO-66-NH掺杂BiS纳米棒和Ag纳米团簇（BiS@UiO-66-NH-S-Ag）后，其光吸收特性从379 nm的紫外区域转移到了约705 nm的可见光区域。制备的BiS@UiO-66-NH-S-Ag和MoS@UiO-66-NH-S-Ag光催化剂对可见光降解MB染料表现出优异的光催化活性。在可见光照射下搅拌90分钟和120分钟内，光催化剂分别使MB溶液（50 ppm）完全脱色。制备的光催化剂的超强光催化性能和循环效率归因于超小银团簇（Ag）在异质结表面的共价锚定。X射线光电子能谱分析证实银团簇的电荷为零。BiS@UiO-66-NH-S-Ag的傅里叶变换红外光谱分析中伯胺的N-H弯曲振动峰消失，证实了受保护的银纳米团簇通过缩合反应共价锚定在UiO-66-NH表面。BiS@UiO-66-NH-S-Ag催化剂表现出优异的循环效率，超过五个循环且活性无明显损失，表明其在工业应用中具有良好的潜力。分别使用吸附-脱附N等温线、X射线衍射（XRD）、高分辨透射电子显微镜（HR-TEM）和场发射扫描电子显微镜（FE-SEM）研究了制备的光催化剂的织构性质、结晶度、相组成、粒径和结构形态。
