MoS2负载量对MoS2/TiO2光催化降解苯酚效率的影响及其作用机理研究

Effect of MoS2 loading on the photocatalytic performance of MoS2/TiO2 nanocomposites in phenol degradation and the corresponding reaction mechanism analysis

  • 摘要: 通过水解法制备TiO2纳米颗粒,与经过超声处理后的MoS2片层纳米材料复合制备MoS2/TiO2纳米催化剂,考察不同MoS2负载量对其光催化降解苯酚效率及路径的影响。XRD、SEM、EDS、FT-IR和UV-vis DRS等表征结果表明,复合催化剂主要由锐钛矿型TiO2和MoS2组成;剥离后的MoS2呈现薄片层状结构,均匀地分散在TiO2纳米颗粒当中。光催化降解苯酚性能测试结果显示,对于MoS2/TiO2催化剂,MoS2负载量的提高有利于光催化降解苯酚效率的提高;当MoS2负载量为27%时,复合MoS2/TiO2纳米颗粒的光催化性能最佳,反应80 min后可将苯酚完全降解。通过对苯酚降解过程中生成中间产物跟踪发现,MoS2负载量的提高有利于促进中间产物苯醌、对苯二酚以及邻苯二酚的生成,进而提升了MoS2/TiO2复合材料的光催化性能。

     

    Abstract: MoS2/TiO2 nanocomposites was prepared by mixing MoS2 with hydrothermally synthesized TiO2; the effects of MoS2 loading on the photocatalytic performance of MoS2/TiO2 in phenol degradation were investigated. The XRD, SEM, EDS, FT-IR and UV-vis DRS characterization results show that for the MoS2/TiO2 nanocomposites, lamellar MoS2 is uniformly dispersed around the TiO2 nanoparticles. The increase of MoS2 loading is beneficial to the photocatalytic degradation of phenol; with a MoS2 loading of 27%, the MoS2/TiO2 nanoparticles exhibited the highest photocatalytic activity, over which phenol can be completely degraded in 80 min. The intermediates during reaction are further tracked to investigate the reaction kinetics of photodegradation of phenol over MoS2/TiO2 nanocomposties. The results reveal that an increase in MoS2 loading is able to promote the formation of various intermediates such as benzoquinone, hydroquinone and catechol, which can further enhance the overall photodegradation efficiency.

     

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