REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto , 4169-007 Porto, Portugal.
ACS Appl Mater Interfaces. 2013 Dec 26;5(24):13382-90. doi: 10.1021/am4042564. Epub 2013 Dec 12.
A novel hybrid composite material, PMo10V2@MIL-101 was prepared by the encapsulation of the tetra-butylammonium (TBA) salt of the vanadium-substituted phosphomolybdate PMo10V2O40 (PMo10V2) into the porous metal-organic framework (MOF) MIL-101(Cr). The materials characterization by powder X-ray diffraction, Fourier transform infrared spectra and scanning electron microscopy confirmed the preparation of the composite material without disruption of the MOF porous structure. Pyrolytic graphite electrodes modified with the original components (MIL-101(Cr), PMo10V2), and the composite material PMo10V2@MIL-101 were prepared and their electrochemical responses were studied by cyclic voltammetry. Surface confined redox processes were observed for all the immobilized materials. MIL-101(Cr) showed one-electron reduction process due to chromium centers (Cr(III) → Cr(II)), while PMo10V2 presented five reduction processes: the peak at more positive potentials is attributed to two superimposed 1-electron vanadium reduction processes (V(V) → V(IV)) and the other four peaks to Mo-centred two-electron reduction processes (Mo(VI) → Mo(V)). The electrochemical behavior of the composite material PMo10V2@MIL-101 showed both MIL-101(Cr) and PMo10V2 redox features, although with the splitting of the two vanadium processes and the shift of the Mo- and Cr- centered processes to more negative potentials. Finally, PMo10V2@MIL-101 modified electrode showed outstanding enhanced vanadium-based electrocatalytic properties towards ascorbic acid oxidation, in comparison with the free PMo10V2, as a result of its immobilization into the porous structure of the MOF. Furthermore, PMo10V2@MIL-101 modified electrode showed successful simultaneous detection of ascorbic acid and dopamine.
一种新型的杂化复合材料 PMo10V2@MIL-101 通过将四丁基铵（TBA）盐的钒取代磷钼酸盐 PMo10V2O40（PMo10V2）封装到多孔金属-有机骨架（MOF）MIL-101（Cr）中制得。粉末 X 射线衍射、傅里叶变换红外光谱和扫描电子显微镜对材料的表征证实了复合材料的制备，而没有破坏 MOF 的多孔结构。用原始成分（MIL-101（Cr）、PMo10V2）和复合材料 PMo10V2@MIL-101 制备了热解石墨电极，并通过循环伏安法研究了它们的电化学响应。所有固定化材料都观察到表面限制的氧化还原过程。MIL-101（Cr）由于铬中心（Cr(III) → Cr(II)）表现出单电子还原过程，而 PMo10V2 则呈现出五个还原过程：在更正的电位处的峰归因于两个叠加的 1 电子钒还原过程（V(V) → V(IV)），而其他四个峰归因于 Mo 中心的双电子还原过程（Mo(VI) → Mo(V)）。复合材料 PMo10V2@MIL-101 的电化学行为表现出 MIL-101（Cr）和 PMo10V2 的氧化还原特征，尽管两个钒过程发生了分裂，而 Mo 和 Cr 中心过程移向更负的电位。最后，PMo10V2@MIL-101 修饰电极在抗坏血酸氧化方面表现出卓越的增强型钒基电催化性能，与游离 PMo10V2 相比，这是由于其固定在 MOF 的多孔结构中。此外，PMo10V2@MIL-101 修饰电极成功地同时检测了抗坏血酸和多巴胺。
