Adsorption is a popular technology for solving water-pollution problems because it is highly efficient, affordable and environmentally friendly. In this study, a dual competition strategy was developed to improve oxytetracycline adsorption by modulating the UiO-66 defects. A series of defect-rich hierarchical porous UiO-66 was prepared using the competitive strategy of bi-metal (Zn/Zr) and bi-ligand (terephthalic acid/monocarboxylic acid). Compared with the pristine UiO-66, the defect-rich hierarchical porous UiO-66 has a higher adsorption efficiency and faster adsorption rate. Among them, the greatest adsorption ability of But-HP-UiO-66 was 209.97 mg∙g at pH= 6.0, which was 9.89 times greater than UiO-66. The kinetic and isotherm fitting results showed that the adsorption was consistent with the Elovich and Freundlich models. According to the response surface model design based on four factors (OTC concentration, pH, humic acid and SO intensity), But-HP-UiO-66 exhibited an excellent adsorption effect and strong anti-jamming ability. The prominent advantages of this composite are its rich pore structure and abundant defects. The adsorption mechanism showed that the electrostatic interactions, metal-organic complexation, pore adsorption, hydrogen bonding and π-π interactions performed vital functions. This study provides a promising method for manufacturing strongly hierarchical porous MOFs and strengthens their potential applications in antibiotic elimination.

中文翻译：

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双竞争策略改性多级孔UiO-66复合材料对土霉素的吸附

吸附是解决水污染问题的热门技术，因为它高效、经济且环保。在本研究中，开发了一种双重竞争策略，通过调节 UiO-66 缺陷来改善土霉素吸附。采用双金属（Zn/Zr）和双配体（对苯二甲酸/一元羧酸）的竞争策略制备了一系列富含缺陷的分级多孔UiO-66。与原始UiO-66相比，富含缺陷的分级多孔UiO-66具有更高的吸附效率和更快的吸附速率。其中，But-HP-UiO-66在pH=6.0时的最大吸附量为209.97 mg∙g，是UiO-66的9.89倍。动力学和等温线拟合结果表明吸附符合Elovich和Freundlich模型。根据基于OTC浓度、pH、腐植酸和SO强度四个因素的响应面模型设计，But-HP-UiO-66表现出优异的吸附效果和较强的抗干扰能力。该复合材料的突出优点是其丰富的孔隙结构和丰富的缺陷。吸附机理表明静电相互作用、金属有机络合、孔隙吸附、氢键和π-π相互作用发挥着重要作用。这项研究为制造强分级多孔 MOF 提供了一种有前途的方法，并增强了它们在消除抗生素方面的潜在应用。