Accelerated photocatalytic degradation of diclofenac by a novel CQDs/BiOCOOH hybrid material under visible-light irradiation: Dechloridation, detoxicity, and a new superoxide radical model study
Accelerated photocatalytic degradation of diclofenac by a novel CQDs/BiOCOOH hybrid material under visible-light irradiation: Dechloridation, detoxicity, and a new superoxide radical model study
复制标题
新型 CQDs/BiOCOOH 杂化材料在可见光照射下加速光催化降解双氯芬酸：脱氯、解毒和新的超氧自由基模型研究
DOI：
10.1016/j.cej.2017.09.118
复制
发表时间：
2018-01-15
影响因子：
15.1
通讯作者：
Liu, Guoguang
中科院分区：
文献类型：
--
作者：
Chen, Ping;Zhang, Qianxin;Liu, Guoguang
一种可见光驱动和环境相容的光催化剂被认为是废水处理工艺的潜在应用。在本研究中，我们利用碳量子点（CQDs）对BiOCOOH进行修饰，目的是消除光催化剂的紫外限制，同时提高其光催化活性。研究了CQDs/BiOCOOH复合材料的结构、形态和其他特性，证实了CQDs与BiOCOOH的成功偶联。在可见光照射下，CQDs含量为2.0%时，其光降解双氯芬酸（DCF）的反应速度是原始BiOCOOH的4.64倍。CQDs有助于增强BiOCOOH的可见光吸收，从而显著提高了可见光收集，以及界面电荷转移和分离。通过一个新的模型研究发现，O-2（中心点-）对DCF的降解起主要作用。通过质谱分析和理论计算，确定了主要中间体，主要途径是e（-）还原反应、O(2)（中心点-）攻击反应和(OH)-O中心点加成反应。选择费氏弧菌、亚棘连丝菌和大水蚤进行急性毒性评价，随着总有机碳和总有机氯化合物的减少，水蚤的急性毒性先升高后降低。合成的CQDs/BiOCOOH光催化剂具有优异的脱氯、矿化和脱毒性能，清楚地表明了该策略的潜力。
A visible light-driven and environmentally compatible photocatalyst is considered to be a potential application for wastewater treatment processes. In the present study, we employed carbon quantum dots (CQDs) to modify BiOCOOH with the aim of negating the UV limit of the photocatalyst, while increasing its photocatalytic activity. The structure, morphologies, and other characteristics of CQDs/BiOCOOH composites were investigated, which confirmed that CQDs were successfully coupled with BiOCOOH. Under visible light irradiation, a very low CQDs content of 2.0% weight resulted in a 4.64-fold more rapid reaction rate in the photodegradation of diclofenac (DCF) than pristine BiOCOOH. The CQDs served to enhance the visible light absorption of BiOCOOH, which significantly improved visible-light harvesting, as well as interfacial charge transfer and separation. Through a new model study it was revealed that O-2(center dot-) was predominantly responsible for DCF degradation. Based on mass spectrometry and theoretical calculations, primary intermediates were identified, and the key pathways proceeded mainly through e(-) reduction, O(2)(center dot-)attack, and (OH)-O-center dot addition reactions. The Vibrio fischeri, Desmodesmus subspicatus, and Daphnia magna were selected to evaluate the acute toxicity, which initially increased and furtherdecreased when the total organic carbon and organic chlorine compounds were reduced. The excellent dechloridation, mineralization, and detoxicity properties via the synthetic CQDs/BiOCOOH photocatalysts clearly demonstrated the potential of this strategy.