State Key Laboratory of Mechanical Transmissions, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, PR China; Chongqing Institute of Modern Construction Industry Development, Chongqing 400060, PR China.
State Key Laboratory of Mechanical Transmissions, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, PR China.
J Colloid Interface Sci. 2019 Nov 15;556:466-475. doi: 10.1016/j.jcis.2019.08.082. Epub 2019 Aug 24.
In this work, we have synthesized Cu-doped MnO@diatomite successfully though a one-step hydrothermal approach. Meanwhile, application for degradation of methylene blue in Fenton-like system was investigated. The compounds were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscope (XPS), Inductively Coupled Plasma analysis (ICP) and UV-vis spectroscopy measurements, beam scanning electron microscope (FIB/SEM), energy dispersive X-ray spectrometer (EDS). The observations revealed that copper was indeed intercalated into layered structure of MnO and Density functional theory (DFT) calculations predicted that Cu intercalated MnO@diatomite brought about the narrowing of band gap and the enhancing of charge mobility during catalysis. Electron Density Difference of CuMnD demonstrated excellent oxidation ability to dissociate HO and generate hydroxyl radical (OH) to degrade the MB. Moreover, the proper copper doping of sample is more easily to form oxygen defect, which generate more surface hydroxyl groups as reaction sites for surface adsorption. In addition, the degradation efficiency of CuMnD was tremendously influenced by the initial pH, HO dosage and copper content of catalyst. Ultimately, 0.02-25-CuMnD along with molar ration of Cu/Mn with 0.4402 showed the best degradation efficiency which was about 96.2% within 4 h with 16.5 mM of HO and pH 2.06.
在这项工作中，我们通过一步水热法成功合成了掺铜的 MnO@硅藻土。同时，研究了其在类芬顿体系中降解亚甲基蓝的应用。通过 X 射线衍射（XRD）、X 射线光电子能谱（XPS）、电感耦合等离子体分析（ICP）和紫外可见光谱测量、束扫描电子显微镜（FIB/SEM）、能谱（EDS）对化合物进行了表征。观察结果表明，铜确实嵌入到 MnO 的层状结构中，密度泛函理论（DFT）计算预测，Cu 嵌入 MnO@硅藻土在催化过程中导致带隙变窄和电荷迁移率提高。CuMnD 的电子密度差显示出优异的氧化能力，能够解离 HO 并生成羟基自由基（OH）以降解 MB。此外，样品中适当的铜掺杂更容易形成氧缺陷，从而产生更多的表面羟基作为表面吸附的反应位点。此外，CuMnD 的降解效率受到初始 pH 值、HO 用量和催化剂中铜含量的极大影响。最终，0.02-25-CuMnD 与 Cu/Mn 的摩尔比为 0.4402 时，在 16.5 mM 的 HO 和 pH 值为 2.06 的条件下，在 4 h 内表现出最佳的降解效率，约为 96.2%。
