MoS_2负载量对MoS_2/TiO_2光催化降解苯酚效率的影响及其作用机理研究

通过水解法制备TiO_2纳米颗粒,与经过超声处理后的MoS_2片层纳米材料复合制备MoS_2/TiO_2纳米催化剂,考察不同MoS_2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TiO_2和MoS_2组成;剥离后的MoS_2呈现薄片层状结构,均匀地分散在TiO_2纳米颗粒当中。光催化降解苯酚性能测试结果显示,对于MoS_2/TiO_2催化剂,MoS_2负载量的提高有利于光催化降解苯酚效率的提高;当MoS_2负载量为27%时,复合M o S2/TiO_2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,MoS_2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MoS_2/TiO_2复合材料的光催化性能。

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

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.