Transition-Metal-Doped Molybdenum Diselenides with Defects and Abundant Active Sites for Efficient Performances of Enzymatic Biofuel Cell and Supercapacitor Applications

We have demonstrated the synthesis of defect-rich Ni-doped MoSe2 nanoplates (NiMoSe2) and their application as an efficient electrocatalyst for enzymatic biofuel cells and electrochemical pseudocapacitors. In this study, a new type of interpretation is proposed that a defective surface facilitates the effective entrapment of enzymes (glucose oxidase (GOD), laccase) for biofuel cells and additional ion diffusion for Faradic charge–discharge reaction. The transmission electron microscopy and UV–vis spectroscopy techniques scrutinized the formation of defects/distortions and the resultant successful entrapment of enzymes. The performed electrochemical characterizations of enzyme-immobilized NiMoSe2/nickel foam (NF) bioanode (NiMoSe2/GOD/NF) and biocathode (NiMoSe2/laccase/NF) exhibited better direct charge conductive behavior at the interface of enzymes and electrode material. Herein, the assembled biofuel cells exhibited an open-circuit voltage (VOC = 0.6 V) and a short-circuit current density (JSC = 8.629 mA cm–2) with a maximum power density (Pmax) of 1.2 mW cm–2. For the electrochemical pseudocapacitor application, the proposed NiMoSe2/NF exhibited excellent specific capacitance (535.74 F g–1), with 86.7% rate performance. Finally, this work suggests new insights into both enzymatic biofuel cell and supercapacitor applications.