Facile synthesis of carbon quantum dots loaded with mesoporous g-C3N4 for synergistic absorption and visible light photodegradation of fluoroquinolone antibiotics
Facile synthesis of carbon quantum dots loaded with mesoporous g-C3N4 for synergistic absorption and visible light photodegradation of fluoroquinolone antibiotics
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轻松合成负载介孔g-C3N4的碳量子点，用于氟喹诺酮类抗生素的协同吸收和可见光光降解
DOI：
10.1039/c7dt04360k
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发表时间：
2018
影响因子：
4
通讯作者：
Liu Guoguang
中科院分区：
文献类型：
--
作者：
Wang Yingfei;Wang Fengliang;Feng Yiping;Xie Zhijie;Zhang Qianxin;Jin Xiaoyu;Liu Haijin;Liu Yang;Lv Wenying;Liu Guoguang
开发一种简便、高效的负载介孔g-C3N4 （mpg-C3N4/CQDs）的碳量子点合成方法迫在眉睫。本研究提出了一种简单的方法，通过煅烧CQDs、氰酰胺和二氧化硅胶体的混合物来合成mpg-C3N4/CQDs。得到的复合材料仍然保留了相当大的总表面积，这可以提供更多的吸附位点；因此提高了氟喹诺酮类抗生素（FQs）的吸附能力。在可见光照射下，mpg-C3N4/CQDs对FQs降解的光催化活性高于散装g-C3N4或mpg-C3N4。这种增强可能归因于mpg-C3N4的高表面积，独特的上转换光致发光（PL）特性以及CQDs的有效电荷分离。FQs的清除符合Langmuir-Hinshelwood （L-H）降解动力学模型和吸收伪二级动力学模型，表明表面反应和化学吸附在光催化过程中起重要作用。电子自旋共振（ESR）技术和活性物质（RSs）清除实验结果表明，超氧阴离子自由基（O2˙−）和光空穴（h+）是引发FQs降解的主要活性物质。基于中间体的鉴定和活性位点的预测，提出了氧氟沙星（OFX）的降解途径。残留抗生素活性实验表明，mpg-C3N4/CQDs具有非常理想的降低抗生素活性的性能。
The development of facile and efficient synthetic approaches of carbon quantum dots loaded with mesoporous g-C3N4 (mpg-C3N4/CQDs) is of critical urgency. Here, a facile strategy was developed to synthesize the mpg-C3N4/CQDs by using calcinations of the mixture of CQDs, cyanamide, and silica colloid. The obtained composite still retained a considerable total surface area, which could offer a larger population of adsorption sites; therefore enhance the capacity for the adsorption of fluoroquinolones antibiotics (FQs). Under visible light irradiation, mpg-C3N4/CQDs demonstrated a higher photocatalytic activity for FQs degradation than did bulk g-C3N4 or mpg-C3N4. This enhancement might have been ascribed to the high surface area of the mpg-C3N4, unique up-converted photoluminescence (PL) properties, and the efficient charge separation of the CQDs. The eradication of FQs followed the Langmuir–Hinshelwood (L–H) kinetic degradation model and absorption pseudo-second-order kinetic model, indicating that surface reactions and chemical sorption played significant roles during the photocatalysis process. The results of electron spin resonance (ESR) technology and reactive species (RSs) scavenging experiments revealed that the superoxide anion radical (O2˙−) and photo-hole (h+) were the primarily active species that initiated the degradation of FQs. Based on the identification of intermediates and the prediction of reactive sites, the degradation pathways of ofloxacin (OFX) were proposed. A residual antibiotic activity experiment revealed that mpg-C3N4/CQDs provided very desirable performance for the reduction of antibiotic activity.