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

Abstract

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 (V OC = 0.6 V) and a short-circuit current density (J SC = 8.629 mA cm–2) with a maximum power density (P max) 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.

Enzymatic Biofuel Cell: Opportunities and Intrinsic Challenges in Futuristic Applications

“…Furthermore, most of the reaction products are tolerable to the host. Therefore, the enzyme electrode does not need to be separated or sealed off from physiological fluid [4c,5f,6,17] . Moreover, the enzymes have excellent specificity so that they not interfered with each other, which make it easier to design EBFCs in to single‐chamber cells without a separator, which greatly improves their miniaturization.…”

“…For glucose/O 2 EBFCs, the chief type of implantable EBFCs, the glucose oxidation reaction at anode was usually catalyzed by GOD or PQQ‐GDH those were sensitive to O 2 , yet O 2 is the only candidate of the cathode‐active reactant [5c,7a,9c,11b] . Therefore, the cathodic reaction and anodic reaction will interfere with each other, leading to a severe limit of the performance of EBFCs.…”

“…[ 3 ] In the beginning, the power output of BFCs is as low as μW cm −2 level. [ 4 ] With the deepening of research and exploration, such as optimizing the battery structure, developing efficient electrode materials, integrating multiple energy sources, etc., the power output of BFCs reaches to a higher threshold (mW cm −2 ), thus opening a practical pathway for low‐power applications [1c,e,4a,5] . However, with the soaring global demand for sustainable energy, the power generation of BFCs is expected to be increased to the magnitude of watt to ensure its practical application.…”

“…Despite tremendous potential of EBFCs in energy storage, [4b,5f,13] implantable energy supply devices, [ 8,11c–e,14 ] and biosensing system, [12i,15] and numerous practical attempts have been launched, the transition from fundamental research to practical application face a series of difficulties. Therefore, it is critical to reveal their inherent challenges via clarifying their structural design principles and working mechanisms.…”

Tungsten-Modulated Molybdenum Selenide/Graphene Heterostructure as an Advanced Electrode for All-Solid-State Supercapacitors

“…Notably, isoelectronic doping of TMDCs can result in the formation of ternary or quaternary alloys, which leads to changes in the physical and chemical properties of the materials (e.g., energy band, electrical, and optical properties) [19][20][21]. Previous reports show electrochemical enhancement and changes in the surface area and conductivity following isoelectronic doping [22,23].…”