School of Environmental Engineering, Wuhan Textile University, Wuhan, 430073, PR China.
College of Environmental and Bioengineering, Henan University of Engineering, No. 1 Xianghe Road, Zhengzhou, 451191, China.
Chemosphere. 2022 Jul;299:134481. doi: 10.1016/j.chemosphere.2022.134481. Epub 2022 Apr 1.
To enhance the efficiency of photogenerated electron transport in the photo-Fenton reaction, we report a Fe-doped UiO-66 containing Fe-O-Zr bonds for the photo-Fenton reaction system. The modulation changes the energy bandgap from 3.89 eV to 2.02 eV, and its absorption edge is red-shifted from the UV region to the visible range. Simultaneously, Fe-O-Zr reduces the redox internal resistance, enhances the photocurrent and catalytic process, and suppresses the compounding of photogenerated electrons and holes. These promote the valence cycling of Fe(III)/Fe(II) in the photo-Fenton reaction. Compared with UiO-66, the hydroxyl radical generation efficiency of this reaction system was increased by 5.8 times (UiO-66: 0.0009 mM/min, FeUiO-1: 0.0053 mM/min). The degradation efficiency of BPA was increased by 100.8 times (UiO-66: 0.0012 min, FeUiO-1: 0.121 min), and the removal rate of TOC also reached 69.55%. The removal rate of BPA was maintained at more than 85% through 5 cycles. The reaction system was able to maintain a removal rate more than 97% at pH:3-9. In the presence of anions, such as Cl, SO, NO (10 mM), the degradation rates of BPA were still above 94%. The catalytic efficiency was 2.02 times higher under natural light than relative to dark conditions. It was demonstrated by EPR and inhibition experiments that the main active species in the reaction were hydroxyl radicals and vacancies. The HOMO energy level and LUMO energy level of the intermediates were analyzed, and the possible degradation pathways of the active species were speculated. Evaluation of the biological toxicity of intermediates demonstrated that the system can effectively detoxify BPA. This investigation provides a reference method to enhance the efficiency of the photo-Fenton reaction of MOFs.
为了提高光芬顿反应中光生电子传输的效率，我们报告了一种含有 Fe-O-Zr 键的 Fe 掺杂 UiO-66，用于光芬顿反应体系。这种调制从 3.89eV 改变能带隙到 2.02eV，其吸收边缘从紫外区红移到可见区。同时，Fe-O-Zr 降低了氧化还原内电阻，增强了光电流和催化过程，抑制了光生电子和空穴的复合。这些促进了光芬顿反应中 Fe(III)/Fe(II)的价循环。与 UiO-66 相比，该反应体系的羟基自由基生成效率提高了 5.8 倍（UiO-66：0.0009mM/min，FeUiO-1：0.0053mM/min）。BPA 的降解效率提高了 100.8 倍（UiO-66：0.0012min，FeUiO-1：0.121min），TOC 的去除率也达到了 69.55%。通过 5 次循环，BPA 的去除率保持在 85%以上。该反应体系在 pH:3-9 时能保持 97%以上的去除率。在阴离子存在下，如 Cl、SO、NO（10mM），BPA 的降解率仍高于 94%。自然光下的催化效率比黑暗条件下高 2.02 倍。通过 EPR 和抑制实验证明，反应中的主要活性物质是羟基自由基和空位。分析了中间体的 HOMO 能级和 LUMO 能级，推测了活性物质的可能降解途径。对中间体生物毒性的评价表明，该体系能有效地解毒 BPA。这项研究为提高 MOFs 光芬顿反应的效率提供了一种参考方法。
