Fabrication and characterization of carbon quantum dots decorated hollow porous graphitic carbon nitride through polyaniline for photocatalysis
Fabrication and characterization of carbon quantum dots decorated hollow porous graphitic carbon nitride through polyaniline for photocatalysis
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DOI：
10.1016/j.cej.2021.131739
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发表时间：
2021-08-24
影响因子：
15.1
通讯作者：
Sasaki, Keiko
中科院分区：
文献类型：
--
作者：
Balakumar, Vellaichamy;Ramalingam, Manivannan;Sasaki, Keiko
无金属光催化剂被广泛用于通过消除有毒和不可生物降解的化合物来净化水溶液。期望开发具有高电荷分离和迁移效率的光催化剂。碳量子点（CQDs）的加入可以提高聚苯胺石墨化氮化碳（PANI）的光吸收能力，减少空穴和电子的复合。在本研究中，一种新型的CQDs修饰聚苯胺与中空多孔石墨氮化碳（CN）通过原位聚合和超声波处理。结果表明，该纳米复合材料具有较高的比表面积和较高的可见光吸收率。在可见光下，环丙沙星（CIP）的光催化降解效果较好. CN-PANICQDs的光催化活性提高了5.0%，这是由于其较高的电荷分离，以及通过CN，PANI和CQDs之间的激发电子异质结破坏了复合速率。高光电流强度、低光致发光发射和电阻进一步证实了这种效应。此外，不同的参数，包括催化剂的重量，初始CIP浓度，和阴离子的干扰效果在CIP去除过程中进行了研究。通过清除剂试验确定了CIP降解的主要活性物种为H+、中心点OH和中心点O-2（-）。该复合光催化剂具有良好的重复使用性和稳定性。确定了降解中间体和反应途径。此外，光催化剂的有效性进行了评估，使用不同的有毒污染物，包括吡虫啉，四环素，苯酚，和罗丹明B在类似的条件下。CQDs修饰的CN-PANI被证明是一种有前途的高效光降解水中有毒污染物的材料。
Metal-free photocatalysts are widely used to decontaminate aqueous solutions by eliminating toxic and nonbiodegradable compounds. It is desirable to develop a photocatalyst with high charge separation and migration efficiency. The addition of carbon quantum dots (CQDs) to graphitic carbon nitride with polyaniline (PANI) can improve its light absorption abilities and reduce the recombination of holes and electrons. In this study, a novel CQDs decorated on PANI with hollow porous graphitic carbon nitride (CN) was fabricated via an in situ polymerization followed by an ultra-sonication. The optimal CQDs-loaded CN-PANI nanocomposite exhibited the high visible light absorption with a high specific surface area. Furthermore, better photocatalytic degradation of ciprofloxacin (CIP) was achieved under the visible light. The improved photocatalytic activity of CN-PANICQDs (5.0%) can be attributed to its higher charge separation, and destruction of recombination rate through the heterojunction of excited electrons among CN, PANI, and CQDs. This effect was further confirmed by high photocurrent intensity, low photoluminescence emission, and electrical resistance. In addition, different parameters including catalyst weight, initial CIP concentration, and interfering effect of anions during CIP removal were investigated. The main active species in the degradation of CIP were identified to h+, center dot OH, and center dot O-2(-) through the scavenger test. The high reusability and stability of the photocatalyst composite were also verified. The degradation intermediates and reaction pathways were identified. Furthermore, the effectiveness of the photocatalyst was evaluated using different toxic pollutants including imidacloprid, tetracycline, phenol, and rhodamine B under similar conditions. The CQDs-decorated CN-PANI was proved as a promising material for efficient photodegradation of toxic pollutants in water.