Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan Institute of Technology, Wuhan, 430205, PR China and Key Laboratory of Novel Reactor and Green Chemical Technology of Hubei Province, Wuhan Institute of Technology, Wuhan 430205, PR China and School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, PR China.
Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan Institute of Technology, Wuhan, 430205, PR China and Key Laboratory of Novel Reactor and Green Chemical Technology of Hubei Province, Wuhan Institute of Technology, Wuhan 430205, PR China and School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430205, PR China and College of Post and Telecommunications, Wuhan Institute of Technology, Wuhan 430073, PR China.
Dalton Trans. 2019 Sep 21;48(35):13260-13272. doi: 10.1039/c9dt02582k. Epub 2019 Aug 16.
A series of multi-shelled Fe/Sn-doped ZnO microspheres were synthesized by calcining carbon microspheres as sacrificial templates. The crystal structure, morphology and optical properties of prepared photocatalysts were investigated by X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Scanning Transmission Electron Microscopy (STEM), X-ray Photoelectron Spectroscopy (XPS), UV-Vis absorption spectroscopy (UV-Vis DRS), Photoluminescence (PL) spectroscopy and transient photocurrent techniques. FESEM and STEM images demonstrated that the samples had a multi-shelled structure and the doping elements were uniformly dispersed in the ZnO matrix. DRS and PL spectra and photocurrent measurements show that the Fe/Sn doped-ZnO samples exhibited higher visible absorption and lower recombination rates of photogenerated electron-hole (e/h) pairs. These advantages resulted in higher photodegradation efficiency of these catalysts towards methylene blue (MB) and ciprofloxacin (CIP). Moreover, the band structure and density of states of the un-doped ZnO and Fe/Sn-doped ZnO models with three different doping ratios were calculated based on the CASTEP code. The roles of the Fe/Sn dopant in the ZnO matrix were found to be band gap control and electron density adjustment due to the Fe(3d) and Sn(5s, 5p) orbitals. This work has a certain reference value for constructing multi-shelled photocatalysts with doping modification and investigating the mechanism of enhanced photoactivity at the microscopic level.
一系列多壳层的 Fe/Sn 掺杂 ZnO 微球通过煅烧碳微球作为牺牲模板合成。采用 X 射线衍射（XRD）、场发射扫描电子显微镜（FESEM）、扫描透射电子显微镜（STEM）、X 射线光电子能谱（XPS）、紫外可见吸收光谱（UV-Vis DRS）、光致发光（PL）光谱和瞬态光电流技术对制备的光催化剂的晶体结构、形貌和光学性质进行了研究。FESEM 和 STEM 图像表明，样品具有多壳层结构，掺杂元素均匀分散在 ZnO 基体中。DRS 和 PL 光谱以及光电流测量表明，Fe/Sn 掺杂-ZnO 样品表现出更高的可见光吸收和更低的光生电子-空穴（e/h）对复合率。这些优势导致这些催化剂对亚甲基蓝（MB）和环丙沙星（CIP）的光降解效率更高。此外，基于 CASTEP 代码计算了未掺杂 ZnO 和具有三种不同掺杂比的 Fe/Sn 掺杂 ZnO 模型的能带结构和态密度。发现由于 Fe(3d)和 Sn(5s, 5p)轨道的存在，Fe/Sn 掺杂剂在 ZnO 基质中的作用是控制能带隙和调整电子密度。这项工作对于构建具有掺杂修饰的多壳层光催化剂和在微观水平上研究增强光活性的机制具有一定的参考价值。
