Department of Inorganic and Analytical Chemistry, University of Szeged, H-6720, Szeged, Dóm tér 7, Hungary.
Department of Applied and Environmental Chemistry, University of Szeged, H-6720, Szeged, Rerrich Béla tér 1, Hungary; Institute of Physical Metallurgy, Metal Forming and Nanotechnology, University of Miskolc, HU-3515, Miskolc, Egyetemváros, Hungary.
Chemosphere. 2021 Oct;280:130636. doi: 10.1016/j.chemosphere.2021.130636. Epub 2021 Apr 23.
BiOI, BiOCl, and their composites (BiOI:BiOCl) with molar ratios from 95:5 to 5:95 were synthesized and tested in the transformation of methyl orange (MO) and sulfamethoxypyridazine (SMP) antibiotic, using three various LED light sources: UV LEDs (398 nm), cool and warm white LEDs (400-700 nm). The 80:20 BiOI:BiOCl photocatalyst showed the best adsorption capacity for MO and enhanced activity compared to BiOI and BiOCl. The apparent quantum yield (Φ) of the MO and SMP transformation for cool and warm white light was slightly lower than for 398 nm UV radiation. The effect of methanol and 1,4-benzoquinone proved that the transformation is initiated mainly via direct charge transfer, resulting in the demethylation of MO and SO extrusion from SMP. The change of photocatalytic efficiency was followed during three cycles. After the first one, the transformation rates decreased, but there was no significant difference between the second and third cycles. The decreased efficiency is most probably caused by the intermediates, whose continuous accumulation was observed during the cycles. Ecotoxicity measurements confirmed that no toxic substances were leached from the catalyst, but the transformation of both MO and SMP results in toxic intermediates. Using 80:20 BiOI:BiOCl and LED light source, the energy requirement of the removal is about half of the value determined using TiO and a mercury vapor lamp. The effect of some components of wastewater (Cl, HCO and humic acids), pH, and two matrices on the composite photocatalysts' efficiency and stability were also investigated.
BiOI、BiOCl 及其摩尔比为 95:5 至 5:95 的复合物（BiOI:BiOCl），使用三种不同的 LED 光源：UV LEDs（398nm）、冷白光和暖白光 LED（400-700nm），用于转化甲基橙（MO）和磺胺甲恶唑（SMP）抗生素。80:20 的 BiOI:BiOCl 光催化剂对 MO 具有最佳的吸附能力，并比 BiOI 和 BiOCl 具有更高的活性。冷白光和暖白光的 MO 和 SMP 转化的表观量子产率（Φ）略低于 398nm UV 辐射。甲醇和 1,4-苯醌的影响证明转化主要是通过直接电荷转移引发的，导致 MO 的脱甲基和 SMP 中 SO 的挤出。在三个循环过程中跟踪光催化效率的变化。第一次循环后，转化率降低，但第二次和第三次循环之间没有明显差异。效率降低的主要原因可能是中间体的不断积累。毒性测量证实催化剂中没有浸出有毒物质，但 MO 和 SMP 的转化会产生有毒中间体。使用 80:20 的 BiOI:BiOCl 和 LED 光源，去除所需的能量约为使用 TiO 和汞蒸气灯确定的值的一半。还研究了废水（Cl、HCO 和腐殖酸）、pH 值以及两种基质的一些成分对复合光催化剂效率和稳定性的影响。
