CuS-Bi2WO6/活性纳米碳纤维的制备及其光催化性能

Preparation and photocatalytic properties CuS-Bi2WO6/carbon nanofibers composites

  • 摘要: 铬是一种常见的重金属污染物,广泛用于各种工业过程。采用溶剂热法制备了不同CNFs(活性纳米碳纤维)含量的CuS-Bi2WO6/CNFs复合光催化剂,改善可见光照射下六价铬的还原。通过XRD、SEM、TEM、FTIR、XPS、UV-Vis、PL和光电流等技术对样品的晶型、形貌、结构、元素组成、表面官能团、光学性质等进行了测试与表征,并考察了CuS-Bi2WO6/CNFs光催化还原Cr(VI)的活性。结果表明,CuS-Bi2WO6/CNFs复合材料的光催化活性明显高于CuS、Bi2WO6和CuS-Bi2WO6。在可见光照射下,1%CuS-Bi2WO6/CNFs对Cr(VI)还原表现出优异的光催化活性,在3 h内还原率为98%。1%CuS-Bi2WO6/CNFs复合材料在4次循环后也表现出良好的稳定性和可回收性。此外,活性基团捕获实验表明,羟基自由基(•OH)、光生空穴(h+)和超氧自由基(•O2)参与了CuS-Bi2WO6/CNFs对Cr(VI)的还原,而•O2是该体系的主要活性组分,并在此基础上初步探讨了光催化反应机制。本文的研究结果表明,通过简单可控的溶剂热法,可以实现CuS-Bi2WO6/CNFs的制备,并且证实了CuS-Bi2WO6/CNFs复合材料在六价铬处理方面的良好前景。

     

    Abstract: Chromium is a common heavy metal pollutant and extensively used in variety of industrial processes. CuS-Bi2WO6/CNFs (carbon nanofibers) composite photocatalysts with different CNFs content were prepared by solvothermal method to remove Cr(VI) from the aqueous solution. The crystal form, morphology, structure, elemental composition, surface functional groups and optical properties of the samples were characterized by XRD, SEM, TEM, FTIR, XPS, UV-Vis and PL. The photocatalytic degradation of Cr(VI) by CuS-Bi2WO6/CNFs composite materials was evaluated. The results show that the photocatalytic activity of the CuS-Bi2WO6/CNFs composite is obviously higher than that of the CuS、Bi2WO6 and CuS/Bi2WO6. Under visible light irradiation, 1%CuS-Bi2WO6/CNFs composites show higher photocatalytic degradation performance, and the reduction rate of Cr(VI) is 98% within 3 h. And 1%CuS-Bi2WO6/CNFs composites also show strong stability and recoverability after four cycles. In addition, the experimental results of active group capture show that hydroxyl radical (•OH), photogenerated hole (h+) and superoxide radical (•O2) are involved in the reduction of Cr(VI) on CuS-Bi2WO6/CNFs, and •O2 is the main active components of the system. The photocatalytic reaction mechanism was discussed. The research results show that the preparation of CuS-Bi2WO6/CNFs can be achieved by a simple and controllable solvothermal method, and it has confirmed the good prospects of CuS-Bi2WO6/CNFs composites in the treatment of hexavalent chromium.

     

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