Bi2S3/CNFs复合材料制备及其光催化性能

Photocatalytic properties of Bi2S3 /CNFs composite photocatalyst and its preparation

摘要:

采用水热法制备硫化铋（Bi2S3）和活性纳米碳纤维掺杂硫化铋复合材料（Bi2S3/CNFs），以降解水溶液中甲硝唑（MTZ）抗生素。通过XRD、SEM、TEM、FT-IR、XPS、UV-vis和PL等对样品的晶型、形貌、结构、元素组成、表面官能团、光学性质等进行表征。结果表明，活性纳米碳纤维（CNFs）引入Bi2S3中，可降低光生电子-空穴对的复合速率，提高其光催化活性。在可见光照射下，考察了Bi2S3/CNFs复合材料光催化降解MTZ的活性，发现CNFs掺量为47%（以Bi2S3质量计，下同）时，Bi2S3/CNFs复合材料光催化性能优异，在3 h内，MTZ的降解率为92%。Bi2S3/CNFs复合材料在三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Bi2S3/CNFs上对MTZ的降解，而·OH和h+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理。

Abstract:

Bismuth sulfide (Bi2S3) and activated carbon nanofiber doped bismuth sulfide composites (Bi2S3/CNFs) were prepared by the hydrothermal method to remove metronidazole (MTZ) from the aqueous solution. The photocatalyst was specified by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy（FT-IR）, X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance and photoluminescence（PL）. The results show that the introduction of active carbon nanofibers (CNFs) into Bi2S3 can reduce the recombination rate of the photogenerated-electron-hole pairs and improve the photocatalytic activity. The photocatalytic degradation of MTZ by Bi2S3/CNFs composite was assessed under visible light irradiation. It was found that the photocatalytic activity of Bi2S3/CNFs composite was excellent when the CNFs content was 47% (based on the mass of Bi2S3, the same below), and the removal rate of MTZ was 92% within 3 h. Bi2S3/CNFs composites also showed strong stability and recoverability after three cycles. In addition, the experimental results of active group capture showed that hydroxyl radical (·OH), photogenerated hole (h+) and superoxide radical (·O2-) were involved in the degradation of MTZ on Bi2S3/CNFs, and·OH and h+ were the main active components of the system.