Synthesis of {P2W18}-based coated structured nano materials with supercapacitors and H2O2 sensing

Abstract

The combination of metal-organic frameworks (MOFs) with large specific surface area and high stability and Dawson-type polyoxometalates (POMs) with excellent electron transfer ability to build a new inorganic-organic hybrid as energy storage materials can give full play to the advantages of both. Therefore, the inorganic organic hybrid nano material {Ag4K2P2W18O62}@[Ag3(μ-Hbtc)(μ-H2btc)]n (which became {Ag4K2P2W18O62}@Ag-BTC, where BTC = 1,3,5-benzenetricarboxylic acid) was synthesized by liquid-assisted grinding. The XRD, SEM, TEM characterization show that {Ag4K2P2W18O62}@Ag-BTC is a coating structure. The specific capacitance is 378.9 F g−1 at a current density of 1 A g−1, with a retention rate of 93.5 % for 5000 cycles. An energy density of 7.8 Wh kg−1 and the power density of 500.0 W kg−1 are obtained in water-based symmetric two-electrode supercapacitor system. In addition, when used as an H2O2 sensor, it has a broad detection range of 1.5 μM to 1.5 mM and the small detection limit of 0.206 μM, also offers excellent interference immunity and stability. Moreover, by applying this nano material to the detection of H2O2 in human serum, results are acceptable. The above result shows that the composite material synthesized by the liquid-assisted grinding method adequately combines properties of both parent materials is a viable strategy for achieving performance enhancement.