Zhang Jianyu, Su Chunli, Xie Xianjun, Liu Peng, Huq Md Enamul
School of Environmental Studies, China University of Geosciences Wuhan 430074 China
State Key Laboratory for Information Engineering in Surveying Mapping and Remote Sensing, Wuhan University Wuhan 430079 China.
RSC Adv. 2020 Oct 7;10(61):37028-37034. doi: 10.1039/d0ra05275b.
HKUST-1 is a copper-based metal-organic framework (MOF) and potential photocatalyst, but minimal research has addressed the performance and mechanism of HKUST-1 in the visible light photocatalytic degradation of dyes. In the present work, HKUST-1 was applied as a photocatalyst to activate peroxomonosulfate (PMS) under visible light (Vis) for dye removal in aqueous solution. The results showed that the removal efficiency of two cationic dyes [rhodamine B (RhB) and methylene blue (MB)] was greater than 95% within 120 min. Free radicals such as SO ˙, ·OH were present in the degradation process, with SO ˙ playing a dominant role. Zeta potential, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy data were used to investigate the degradation mechanism. In the degradation process, surface charge attraction between HKUST-1 and cationic dyes promotes removal efficiency, with the degradation efficiency of cationic dyes (MB and RhB) more than 50% higher than for anionic dyes [acid orange 7 (AO) and methyl red (MR)]. On the other hand, HKUST-1 has been proved to activate PMS by conducting photoelectrons, which accelerated the degradation of dyes. Compared with the reaction conditions of PMS/Vis, when the HKUST-1 was present (HKUST-1/PMS/Vis), the degradation rates of MB and RhB increased by 62.7 and 63.2%, respectively.
HKUST-1是一种铜基金属有机框架材料（MOF），也是一种潜在的光催化剂，但针对HKUST-1在可见光光催化降解染料方面的性能和机理的研究极少。在本研究中，HKUST-1被用作光催化剂，在可见光（Vis）下活化过一硫酸盐（PMS）以去除水溶液中的染料。结果表明，两种阳离子染料[罗丹明B（RhB）和亚甲基蓝（MB）]在120分钟内的去除效率大于95%。降解过程中存在诸如SO˙、·OH等自由基，其中SO˙起主导作用。利用zeta电位、X射线光电子能谱和光致发光光谱数据研究了降解机理。在降解过程中，HKUST-1与阳离子染料之间的表面电荷吸引提高了去除效率，阳离子染料（MB和RhB）的降解效率比阴离子染料[酸性橙7（AO）和甲基红（MR）]高出50%以上。另一方面，已证明HKUST-1通过传导光电子来活化PMS，从而加速了染料的降解。与PMS/Vis的反应条件相比，当存在HKUST-1（HKUST-1/PMS/Vis）时，MB和RhB的降解速率分别提高了62.7%和63.2%。
