Suzhou Key Laboratory of Green Chemical Engineering, School of Chemical and Environmental Engineering, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu, 215123, China; Université Clermont Auvergne, CNRS, SIGMA Clermont, Institut de Chimie de Clermont-Ferrand, F-63000 Clermont-Ferrand, France; Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China.
Université Clermont Auvergne, CNRS, SIGMA Clermont, Institut de Chimie de Clermont-Ferrand, F-63000 Clermont-Ferrand, France.
Chemosphere. 2020 Nov;258:127268. doi: 10.1016/j.chemosphere.2020.127268. Epub 2020 Jun 12.
In this work, UVA radiation that is part of solar light is taken as the irradiation source and radicals (HO, SO and HO/O) are generated through activation of hydrogen peroxide (HO), sodium persulfate (NaSO) and Bismuth catalyst (BiOCl), respectively. The distinguished performance in removing acetaminophen (ACTP), a model pharmaceutical pollutant, by these three radicals was compared for the first time. Effect of pH, halide ions concentration and interfacial mechanism have been investigated in detail. Interestingly, results show that heterogeneous UVA/BiOCl process has higher degradation efficiency than homogeneous UVA/HO and UVA/NaSO systems whatever the solution's pH. To explain these results, second order reaction rate constant (k) have been determined with laser flash photolysis (LFP) or radical scavenging experiments. The strongly interfacial-depended HO/O radicals have the lowest second order rate constant with ACTP but highest steady state concentration. BiOCl is much easier activated by UVA, and outstanding ACTP mineralization can be achieved. Combination of BiOCl and NaSO exhibits synergistic effects rather than antagonism effects with HO. This study highlights the relative effective utilization of solar light through interfacial directed BiOCl photocatalysis and its synergistic effects with traditional oxidants.
在这项工作中，我们将太阳光线中的 UVA 辐射作为辐照源，通过激活过氧化氢 (HO)、过硫酸钠 (NaSO) 和铋催化剂 (BiOCl)，分别产生自由基 (HO、SO 和 HO/O)。首次比较了这三种自由基在去除模型药物污染物对乙酰氨基酚 (ACTP) 方面的优异性能。详细研究了 pH 值、卤化物离子浓度和界面机制的影响。有趣的是，结果表明，无论溶液的 pH 值如何，多相 UVA/BiOCl 工艺的降解效率均高于均相 UVA/HO 和 UVA/NaSO 体系。为了解释这些结果，我们使用激光闪光光解 (LFP) 或自由基清除实验确定了二级反应速率常数 (k)。具有强界面依赖性的 HO/O 自由基与 ACTP 的二级速率常数最低，但稳态浓度最高。BiOCl 更容易被 UVA 激活，并且可以实现出色的 ACTP 矿化。BiOCl 和 NaSO 的组合表现出协同作用，而不是与 HO 的拮抗作用。本研究强调了通过界面定向 BiOCl 光催化和与传统氧化剂的协同作用相对有效地利用太阳能。
