An iron based organic framework coated with nickel hydroxide for energy storage, conversion and detection.

Although electrode materials based on metal organic frameworks (MOFs) were widely studied in the electrochemistry field, the origin of poor conductivity is still a bottleneck restricting their development. Herein, we constructed a conductive circuit by growing a layer of hydroxide on the surface of the Fe-MOF, and composite materials (Fe-MOF@Ni(OH)2) are applied in the fields of supercapacitor, OER, and electrochemical sensing. Fe-MOF@Ni(OH)2 not only maintains the intrinsic advantages of Fe-MOF, but also improves the electrical conductivity. Fe-MOF@Ni(OH)2 exhibits a high specific capacity of 188 mAh g-1 at 1 A g-1 . The energy density of the asymmetric supercapacitor (Fe-MOF@Ni(OH)2-20//AC) reaches 67.1 Wh kg-1. During the oxygen evolution reaction, the overpotential of the material is 280 mV at 10 mA cm-2, and the Tafel slope is 37.6 mV dec-1. The electrochemical sensing tests showed the detection limit of BPA is 5 μM. Hence, these results provide key insights into the design of multifunctional electrode materials.