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.