Abstract:
The production of cheap, efficient, and stable photocatalysts for degrading antibiotic contaminants remains challenging. Herein, Bi2O3/boron nitride (BN)/Co3O4 ternary composites were synthesized using the impregnation method. The morphological characteristics, structural features, and photochemical properties of the prepared photocatalysts were investigated via X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy, and ultraviolet-visible (Vis) diffuse reflectance spectrum techniques. BN was used as a charge transfer bridge in the ternary composites, which afforded a heterojunction between the two semiconductors. The formation of the heterojunction substantially enhanced the charge separation and improved the photocatalyst performance. The degradation activity of the Bi2O3/BN/Co3O4 ternary composites against norfloxacin (NOR) under Vis light irradiation was investigated. The degradation rate of NOR using 5-wt% Bi2O3/BN/Co3O4 reached 98% in 180 min, indicating excellent photocatalytic performance. The ternary composites also exhibited high photostability with a degradation efficiency of 88.4% after five cycles. Hydroxyl radicals (•OH), superoxide radicals (•O2-), and holes (h+) played a synergistic role in the photocatalytic reaction, where h+ and •O2- were more important than •OH. Consequently, seven intermediates and major photocatalytic degradation pathways were identified. Toxicity experiments showed that the toxicity of the degradation solution to Chlorella pyrenoidosa decreased. Finally, the ecotoxicity of NOR and its intermediates were analyzed using the Toxicity Estimation Software Tool, with most intermediates exhibiting low toxicity.
摘要:
廉价的生产,高效,和稳定的光催化剂降解抗生素污染物仍然具有挑战性。在这里,采用浸渍法合成了Bi2O3/氮化硼(BN)/Co3O4三元复合材料。形态特征,结构特征,并通过X射线衍射研究了所制备的光催化剂的光化学性质,傅里叶变换红外光谱,X射线光电子能谱,扫描电子显微镜,高分辨率透射电子显微镜,和紫外可见(Vis)漫反射光谱技术。BN被用作三元复合材料中的电荷转移桥,这提供了两个半导体之间的异质结。异质结的形成大大增强了电荷分离并改善了光催化剂的性能。研究了Bi2O3/BN/Co3O4三元复合材料在可见光照射下对诺氟沙星(NOR)的降解活性。使用5-wt%的Bi2O3/BN/Co3O4在180分钟内对NOR的降解率达到98%,表明优异的光催化性能。该三元复合材料在5次循环后还表现出高的光稳定性,降解效率为88.4%。羟基(•OH),超氧自由基(•O2-),空穴(h+)在光催化反应中起到了协同作用,其中h+和·O2-比·OH更重要。因此,确定了七个中间体和主要的光催化降解途径。毒性实验表明,降解液对蛋白核小球藻的毒性降低。最后,使用毒性估计软件工具分析NOR及其中间体的生态毒性,大多数中间体表现出低毒性。