Cravanzola Sara, Sarro Marco, Cesano Federico, Calza Paola, Scarano Domenica
Department of Chemistry, NIS (Nanostructured Interfaces and Surfaces) Inter-Departmental Centre and INSTM Centro di Riferimento, University of Torino, Via P. Giuria, 7, 10125 Torino, Italy.
Nanomaterials (Basel). 2018 Mar 29;8(4):207. doi: 10.3390/nano8040207.
S-doped TiO₂ and hybrid MoS₂/TiO₂ systems have been synthesized, via the sulfidation with H₂S of the bare TiO₂ and of MoO supported on TiO₂ systems, with the aim of enhancing the photocatalytic properties of TiO₂ for the degradation of carbamazepine, an anticonvulsant drug, whose residues and metabolites are usually inefficiently removed in wastewater treatment plants. The focus of this study is to find a relationship between the morphology/structure/surface properties and photoactivity. The full characterization of samples reveals the strong effects of the H₂S action on the properties of TiO₂, with the formation of defects at the surface, as shown by transmission electron microscopy (TEM) and infrared spectroscopy (IR), while also the optical properties are strongly affected by the sulfidation treatment, with changes in the electronic states of TiO₂. Meanwhile, the formation of small and thin few-layer MoS₂ domains, decorating the TiO₂ surface, is evidenced by both high-resolution transmission electron microscopy (HRTEM) and UV-Vis/Raman spectroscopies, while Fourier-transform infrared (FTIR) spectra give insights into the nature of Ti and Mo surface sites. The most interesting findings of our research are the enhanced photoactivity of the MoS₂/TiO₂ hybrid photocatalyst toward the carbamazepine mineralization. Surprisingly, the formation of hazardous compounds (i.e., acridine derivatives), usually obtained from carbamazepine, is precluded when treated with MoS₂/TiO₂ systems.
通过对裸露的TiO₂以及负载在TiO₂体系上的MoO₂用H₂S进行硫化处理,合成了S掺杂的TiO₂和MoS₂/TiO₂混合体系,目的是提高TiO₂对卡马西平(一种抗惊厥药物)降解的光催化性能,其残留和代谢产物在废水处理厂中通常难以有效去除。本研究的重点是找出形态/结构/表面性质与光活性之间的关系。样品的全面表征揭示了H₂S作用对TiO₂性质的强烈影响,通过透射电子显微镜(TEM)和红外光谱(IR)表明在表面形成了缺陷,同时光学性质也受到硫化处理的强烈影响,TiO₂的电子态发生了变化。与此同时,高分辨率透射电子显微镜(HRTEM)和紫外-可见/拉曼光谱都证明了在TiO₂表面形成了小而薄的几层MoS₂域,而傅里叶变换红外(FTIR)光谱则深入了解了Ti和Mo表面位点的性质。我们研究中最有趣的发现是MoS₂/TiO₂混合光催化剂对卡马西平矿化的光活性增强。令人惊讶的是,当用MoS₂/TiO₂体系处理时,通常由卡马西平产生的有害化合物(即吖啶衍生物)的形成被阻止了。