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Journal of ZheJiang University (Engineering Science)  2022, Vol. 56 Issue (3): 476-484    DOI: 10.3785/j.issn.1008-973X.2022.03.006
Photocatalytic performance of ZnO/g-C3N4 composite photocatalysts in microfluidic reactors
Hua-zhen LIU(),Hao ZHOU*()
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China
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The ZnO/g-C3N4 composite photocatalysts with different mass fractions of ZnO were synthesized by a simple impregnation method. The structure, morphology, chemical compositions and optical properties of the samples were analyzed. The as-prepared samples were fixed to microfluidic reactors, respectively. The photocatalytic performance of these reactors was evaluated by the degradation of different dyes (methylene blue, neutral red, malachite green, and rhodamine B) under visible light. The characterization indicated that there was an interaction between ZnO and g-C3N4 in the as-prepared composite. And the composite could make good use of visible light. Also, compared with g-C3N4, the recombination of photogenerated electron-hole pairs in the composite was obviously inhibited. The results of photocatalytic experiments displayed that 6% ZnO/g-C3N4 exhibited the best photocatalytic performance compared to other mass fractions of ZnO. When the light intensity was 60 klx and the liquid flow rate was 20 μL/min, the degradation efficiency of rhodamine B solution reached 98.9%. The photocatalytic degradation of methylene blue by multiple cycle tests was also studied, indicating the sample's stability and reliability when conducting photocatalytic degradation experiments in microfluidic reactors.

Key wordsZnO/g-C3N4 composite      photocatalytic technology      microfluidic reactor      degradation of dye     
Received: 26 March 2021      Published: 29 March 2022
CLC:  X 703  
Fund:  国家自然科学基金创新研究群体项目(51621005)
Corresponding Authors: Hao ZHOU     E-mail:;
Cite this article:

Hua-zhen LIU,Hao ZHOU. Photocatalytic performance of ZnO/g-C3N4 composite photocatalysts in microfluidic reactors. Journal of ZheJiang University (Engineering Science), 2022, 56(3): 476-484.

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采用浸渍法合成ZnO质量分数不同的ZnO/g-C3N4复合光催化剂,分析样品的结构、形态、化学组成和光学性能等. 将制备好的样品固定到微流控芯片中,降解不同的染料(亚甲基蓝、中性红、孔雀石绿、罗丹明B),评价样品在可见光下的光催化性能. 样品的表征结果表明,在ZnO/g-C3N4复合物中,ZnO、g-C3N4间存在相互作用,ZnO/g-C3N4复合物对可见光的利用更为充分;与g-C3N4相比,在ZnO/g-C3N4复合物中光生电子-空穴对的复合明显被抑制. 光催化实验结果表明,6 % ZnO/g-C3N4具有最佳光催化性能,在光照强度为60 klx,液体流速为20 μL/min时,其对罗丹明B溶液的降解效率为98.9%.多次循环后的光催化降解亚甲基蓝性能研究表明,样品在微流控芯片中进行光催化降解实验具有稳定性和可靠性.

关键词: ZnO/g-C3N4复合材料,  光催化技术,  微流控芯片,  降解染料 
Fig.1 Photo of microfluidic reactor and design of microchannels
Fig.2 Fabrication process of microfluidic reactor
Fig.3 Schematic diagram of experimental system
Fig.4 XRD patterns of prepared CN, ZnO, ZnO/CN composites
Fig.5 SEM images of CN, ZnO and 6% ZnO/CN and EDS image of 6% ZnO/CN
Fig.6 FT-IR spectra of CN, ZnO and 6% ZnO/CN photocatalysts
Fig.7 High resolution XPS spectra of CN, ZnO and 6% ZnO/CN
Fig.8 Optical properties analysis of CN, ZnO and 6% ZnO/CN composites
Fig.9 PL spectra of CN, ZnO/CN composites excited at 365 nm
Fig.10 Effect of flow rate on photocatalytic degradation efficiency of MB solution (light intensity: 50 klx)
Fig.11 Effect of light intensity on photocatalytic degradation efficiency of MB solution (flow rate: 20 μL/min)
Fig.12 Cycle runs of photocatalytic degradation MB solution experiment (light intensity: 60 klx, flow rate: 20 μL/min)
Fig.13 Photocatalytic degradation of NR, MG and MB solution with different photocatalysts (light intensity: 60 klx, flow rate: 20 μL/min)
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