Fabrication of 3D bi-functional binder-free electrode by hydrothermal growth of MIL-101(Fe) framework on nickel foam: A supersensitive electrochemical sensor and highly stable supercapacitor

In present investigation, we report unique and successful fabrication of 3D bi-functional binder free electrode by hydrothermal growth of Fe based metal organic frameworks on nickel foam (MIL-101(Fe)/NF) for supersensitive electrochemical sensor and high capacitance supercapacitor. The materials characteristics were investigated by XRD, FTIR, RAMAN, FE-SEM, and BET techniques. The FE-SEM results revealed the formation of octahedral spindles nanosheets of MIL-101(Fe) fully covered on the nickel foam. In applications involving an electrochemical sensor or a supercapacitor, the binder-free MIL-101(Fe)/NF electrode provided excellent results by modestly avoiding dead mass of binders. The determination capability of MIL-101(Fe)/ NF electrode as an electrochemical sensor of lead (Pb2+) ions has been investigated by differential pulse voltammetry (DPV) technique. According to the findings, the MIL-101(Fe)/NF exhibits excellent sensing performance towards Pb2+ ions with low detection limit of 0.169 nM and high sensitivity of 22.6 mu A/M. Moreover, the electrode exhibits ideal sensor characteristics such as good selectivity, reproducibility, repeatability and stability. In addition, the structure of MIL-101(Fe)/NF electrode provides elevated electroactive sites, which altogether provides shorter path for electron passage and electrolyte diffusion process, which resulted in a high specific capacitance. At a scan rate of 10 mVs1, the MIL-101(Fe)/NF electrode exhibits a specific capacitance of 210 Fg-1. Capacitance retention of greater than 98% is demonstrated by the fabricated electrode, even after 1000 cycles. The present investigated results and novel strategies to develop multifunctional materials will open innovative avenues for material scientist.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

In this study, a 3D bi-functional binder-free electrode was successfully fabricated by hydrothermal growth of Fe based metal organic frameworks on nickel foam. The electrode demonstrated excellent performance as an electrochemical sensor and a supercapacitor. The results showed that the electrode exhibited high sensitivity, selectivity, reproducibility, and stability as an electrochemical sensor, and high specific capacitance with good capacitance retention as a supercapacitor.