Simple preparation of Ag-BTC-modified Co3Mo7O24 mesoporous material for capacitance and H2O2-sensing performances

Abstract

Injecting polyoxometalate (POM) clusters into metal organic frameworks (MOFs) can not only provide more additional redox centers, but also solve the problems of easy agglomeration and low stability of POMs. Herein, we prepared {Co₃Mo₇O₂₄}@[Ag₄(μ-Hbtc)(μ-H₂btc)]_1/2 (shortened as {Co₃Mo₇O₂₄}@Ag-BTC-2, btc = 1,3,5-benzyltricarboxylic acid) by a simple grinding method and characterized its morphology and composition. {Co₃Mo₇O₂₄}@Ag-BTC-2 showed high specific capacitance (260.7 F g⁻¹) and high capacitance retention (99.8% after 5000 cycles) in a three-electrode system with nickel foam as a collector. A symmetrical supercapacitor fabricated with {Co₃Mo₇O₂₄}@Ag-BTC-2 delivers an energy density of 4.9 W h kg⁻¹ at 355.1 W kg⁻¹. The capacitance retention reached 97.6% after 5000 cycles. In addition, {Co₃Mo₇O₂₄}@Ag-BTC-2 as a H₂O₂ sensor showed a wide linear range (1 μM to 0.43 mM), a low detection limit (0.33 μM) and a strong anti-interference ability, and can be used to detect H₂O₂ in real blood serum specimens. These results show that POMOF materials with high performance can be prepared by a simple grinding method.