RESUMO
To address the poor electronic conductivity and easily dissolved in electrolyte of polyoxometalates (POMs), and considering the high electrical conductivity and configuration advantages of crumpled graphene balls (CGBs), herein, a series of POM-based coordination polymers [Cu(pyttz)2 ]PMo12 @CGB (n, n=1, 2, 3) were successfully synthesized, and electrochemical lithium storage performance and lithium ion diffusion kinetics were comprehensively investigated. Galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS) study confirm that [Cu(pyttz)2 ]PMo12 @CGB (n, n=1, 2, 3) integrates the advantage of high electronic conductivity of CGB and excellent Li+ migration kinetics of POMs, which greatly ameliorates the electrochemical performances of POMs, among [Cu(pyttz)2 ]PMo12 @CGB (2) exhibits an excellent reversible specific capacity of around 941.4â mA h g-1 at 0.1â A g-1 after 150â cycles and admirable rate performance. This work will promote the development of POMCP anodes, thus fulfilling their potential in high-performance LIBs.
RESUMO
To improve the peroxidase-like activities of metal-organic frameworks (MOFs) as nanozymes, a ternary MIL-100(Fe)@PMo12@3DGO nanocomposite was designed and fabricated by encapsulating Keggin-type H3PMo12O40 (PMo12) with fast and reversible multi-electron redox processes and an electron-rich structure into MIL-100(Fe), then being covered by three-dimensional graphene (3DGO) with higher conductivity, larger surface area, higher porosity, and better chemical stability. As a consequence, the as-prepared MIL-100(Fe)@PMo12@3DGO nanocomposite exhibits excellent peroxidase-like activities, namely, the lowest limit of detection (0.14 µM) in the range of 1-100 µM for glucose to date, to the best of our knowledge, attributed to the individual and synergistic effects of H3PMo12O40, 3DGO and MIL-100(Fe).