催化学报

催化学报 ›› 2020, Vol. 41 ›› Issue (3): 474-484.DOI: 10.1016/S1872-2067(19)63501-1

• 论文 • 上一篇    下一篇

氧化石墨烯量子点修饰氧掺杂多孔g-C3N4在光催化降解和抗菌中的应用

徐婧a,b,c,d, 黄金a,b,c,d, 王周平a,b,c,d, 朱永法e   

  1. a 江南大学食品科学与技术国家重点实验室, 江苏无锡 214122;
    b 江南大学食品学院, 江苏无锡 214122;
    c 江南大学食品安全国际合作联合实验室, 江苏无锡 214122;
    d 江苏省食品安全与质量控制协同创新中心, 江苏无锡 214122;
    e 清华大学化学系, 北京 100084
  • 收稿日期:2019-07-25 修回日期:2019-09-04 出版日期:2020-03-18 发布日期:2019-11-19
  • 通讯作者: 王周平, 朱永法
  • 基金资助:
    国家自然科学基金（21707052）；江苏省农业科技自主创新资金（CX（18）2025）；中央高校基本科研业务费专项资金（JUSRP11905，JUSRP51714B）；江苏省重点研发计划（BE2017623）.

Enhanced visible-light photocatalytic degradation and disinfection performance of oxidized nanoporous g-C3N4 via decoration with graphene oxide quantum dots

Jing Xua,b,c,d, Jin Huanga,b,c,d, Zhouping Wanga,b,c,d, Yongfa Zhue   

  1. a State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China;
    b School of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China;
    c International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, Jiangsu, China;
    d Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi 214122, Jiangsu, China;
    e Department of Chemistry, Tsinghua University, Beijing 100084, China
  • Received:2019-07-25 Revised:2019-09-04 Online:2020-03-18 Published:2019-11-19
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (21707052), Jiangsu Agriculture Science and Technology Innovation Fund (CX(18)2025), Fundamental Research Funds for the Central Universities (JUSRP11905 and JUSRP51714B), and Key Research and Development Program of Jiangsu Province (BE2017623).

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摘要： 偶氮类合成色素具有遗传毒性、致癌性和致泻性，而食源性致病菌易引发细菌性感染和食物中毒事件，食品加工过程中产生的色素废水和致病菌废水若未经妥善处理就排入水体，会对水体及环境造成污染，废水中的偶氮类色素和致病菌还会通过食物链对人体健康产生威胁.因此，寻求更为高效、绿色、安全的处理技术和净化材料有效去除食品废水中高污染性和毒害性的偶氮类色素和致病菌显得尤为迫切.
g-C3N4是一种具有可见光响应的有机半导体光催化材料，广泛应用于降解污染物、杀灭致病菌、催化有机反应等领域.然而，g-C3N4本身存在着比表面积小、光吸收性能差、光氧化能力低以及光生载流子迁移效率低等缺点，限制了其光催化性能.针对上述问题，我们对g-C3N4的空间和电子结构进行了设计，将形貌调控、元素掺杂和助催化剂修饰三种改性方法相结合，以获得兼具大比表面积、优异光吸收性能、强氧化能力以及快速光生载流子迁移能力的高活性g-C3N4基光催化体系.
本文通过水热法制备了氧掺杂多孔氮化碳（PCNO），通过酸剥离法制备了氧化石墨烯量子点（ox-GQDs），最后通过自组装法将助催化剂ox-GQDs修饰到PCNO上，制备了ox-GQDs/PCNO复合光催化剂.零维的ox-GQDs可以通过氢键、π-π作用和化学键作用，与二维的PCNO实现紧密接触，均匀地分散在PCNO的表面和内部孔道上.由于ox-GQDs独特的上转换特性、电子捕获能力和过氧化物酶活性，ox-GQDs/PCNO复合光催化剂具有比PCNO更佳的光吸收性能、更高的电荷转移效率以及更强的光氧化能力.因此，ox-GQDs/PCNO复合材料在降解偶氮类色素和杀灭致病菌方面均表现出更为优异的可见光催化性能，活性最佳的复合材料ox-GQDs-0.2%/PCNO降解偶氮类色素苋菜红的速率常数约是PCNO的3.1倍，并且该材料能在可见光照射4 h内杀灭99.6%的大肠杆菌，远超过PCNO 31.9%的抗菌活性.另外，光生空穴、超氧自由基和羟基自由基被证实是ox-GQDs/PCNO体系在光催化反应中产生的活性物种，可以彻底矿化偶氮类色素并有效杀灭致病菌.本研究可以拓展g-C3N4基光催化剂在环境净化领域的应用前景，并为阐明ox-GQDs在复合光催化体系中的作用提供新的见解.

 

关键词: 光催化, 氧掺杂多孔g-C3N4, 氧化石墨烯量子点, 降解, 抗菌

Abstract: Oxidized nanoporous g-C3N4 (PCNO) decorated with graphene oxide quantum dots (ox-GQDs) was successfully prepared by a facile self-assembly method. As co-catalysts, the ultrasmall zero-dimensional (0D) ox-GQDs can achieve uniform dispersion on the surface/inner channels of PCNO, as well as intimate contact with PCNO through hydrogen bonding, π-π, and chemical bonding interactions. In contrast with PCNO, the ox-GQDs/PCNO composite photocatalysts possessed improved light-harvesting ability, higher charge-transfer efficiency, enhanced photooxidation capacity, and increased amounts of reactive species due to the upconversion properties, strong electron capturing ability, and peroxidase-like activity of the ox-GQDs. Therefore, the visible-light photocatalytic degradation and disinfection performances of the ox-GQDs/PCNO composite were significantly enhanced. Remarkably, the composite with a 0.2 wt.% deposited amount of ox-GQDs (ox-GQDs-0.2%/PCNO) exhibited optimum amaranth photodegradation activity, with a corresponding rate about 3.1 times as high as that of PCNO. In addition, ox-GQDs-0.2%/PCNO could inactivate about 99.6% of Escherichia coli (E. coli) cells after 4 h of visible light irradiation, whereas only~31.9% of E. coli cells were killed by PCNO. Furthermore, h+,·O2-, and·OH were determined to be the reactive species generated in the photocatalytic process of the ox-GQDs/PCNO system; these species can thoroughly mineralize azo dyes and effectively inactivate pathogenic bacteria.

Key words: Photocatalysis, Oxidized nanoporous g-C3N4, Graphene oxide quantum dots, Degradation, Disinfection

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