The present study considers the ways in which redox enzyme modules are coupled in living cells for linking reductive and oxidative half-reactions, and then reviews examples in which this concept can ...be exploited technologically in applications of coupled enzyme pairs. We discuss many examples in which enzymes are interfaced with electronically conductive particles to build up heterogeneous catalytic systems in an approach which could be termed synthetic biochemistry We focus on reactions involving the H
/H
redox couple catalysed by NiFe hydrogenase moieties in conjunction with other biocatalysed reactions to assemble systems directed towards synthesis of specialised chemicals, chemical building blocks or bio-derived fuel molecules. We review our work in which this approach is applied in designing enzyme-modified particles for H
-driven recycling of the nicotinamide cofactor NADH to provide a clean cofactor source for applications of NADH-dependent enzymes in chemical synthesis, presenting a combination of published and new work on these systems. We also consider related photobiocatalytic approaches for light-driven production of chemicals or H
as a fuel. We emphasise the techniques available for understanding detailed catalytic properties of the enzymes responsible for individual redox half-reactions, and the importance of a fundamental understanding of the enzyme characteristics in enabling effective applications of redox biocatalysis.
Photoreforming of lignocellulose is a promising approach toward sustainable H2 generation, but this kinetically challenging reaction currently requires UV-absorbing or toxic light absorbers under ...harsh conditions. Here, we report a cyanamide-functionalized carbon nitride, NCN CN x , which shows enhanced performance upon ultrasonication. This activated NCN CN x allows for the visible-light driven conversion of purified and raw lignocellulose samples into H2 in the presence of various proton reduction cocatalysts. The reported room-temperature photoreforming process operates under benign aqueous conditions (pH ≈ 2–15) without the need for toxic components.
Photoreforming of lignocellulose is a promising approach toward sustainable H
generation, but this kinetically challenging reaction currently requires UV-absorbing or toxic light absorbers under ...harsh conditions. Here, we report a cyanamide-functionalized carbon nitride,
CN
, which shows enhanced performance upon ultrasonication. This activated
CN
allows for the visible-light driven conversion of purified and raw lignocellulose samples into H
in the presence of various proton reduction cocatalysts. The reported room-temperature photoreforming process operates under benign aqueous conditions (pH ≈ 2-15) without the need for toxic components.
Long cycle life and high energy/power density are imperative to energy storage systems. Polyaniline (PANI) has shown great potential as an electrode material but is limited by poor cycling and rate ...performance. We present a molecular design approach of binding short-chain aniline trimers (ATs) and carbon nanotubes (CNTs) through the formation of amide covalent linkages enabled by a simple laser scribing technique. The covalently coupled AT/CNT (cc-AT/CNT) composite retains 80% of its original capacitance after 20 000 charge/discharge cycles, which readily outperforms long-chain PANI/CNT composites without covalent connections. The compact AT/CNT heterointerfaces produce fast charge/discharge kinetics and excellent rate capability. The flexible symmetric quasi-solid-state devices can be stably cycled beyond 50 000 cycles, at least 5 times longer than most PANI/CNT-based symmetric supercapacitors reported to date. This molecular design of durable conducting polymer-based electrode materials enabled by laser irradiation presents a feasible approach toward robust advanced energy storage devices.
Energy storage technologies have emerged as a critical component in the sustainable development of the global energy landscape. Aqueous energy storage systems are considered to be a promising ...solution to reliably store the energy generated from renewable sources and deliver electricity to the grid on demand. From bulk storage to uninterrupted power supply, large-scale energy storage systems of various power capacity and discharge frequency are needed, requiring rational designs of different electrochemical systems. In this work, unconventional high-energy-density supercapacitors and innovative fast-charging batteries are explored. Utilizing a facile laser scribing fabrication approach, earth-abundant, low-cost, electrochemically active vanadium oxides are incorporated onto highly conductive graphene scaffold. Symmetric supercapacitors based on this composite electrode exhibit high energy densities that are close to conventional batteries. Furthermore, with synthetic modifications, the vanadium oxides/graphene composite is applied as the cathode material in a zinc-ion battery, leading to state-of-the-art rate capability and high-rate cycling stability. Moreover, the synthesis and charge storage mechanism of the pseudocapacitive electrode are further investigated in an aqueous hybrid Li-ion battery.
Technological breakthroughs in energy storage are being driven by the development of next‐generation supercapacitors with favorable features besides high‐power density and cycling stability. In this ...innovation, graphene and its derived materials play an active role. Here, the research status of graphene supercapacitors is analyzed. Recent progress is outlined in graphene assembly, exfoliation, and processing techniques. In addition, electrochemical and electrical attributes that are increasingly valued in next‐generation supercapacitors are highlighted along with a summary of the latest research addressing chemical modification of graphene and its derivatives for future supercapacitors. The challenges and solutions discussed in the review hopefully will shed light on the commercialization of graphene and a broader genre of 2D materials in energy storage applications.
Next‐generation supercapacitors with features beyond high‐power density and cycling stability are crucial for advancing energy storage technologies. This review analyzes the research status of graphene supercapacitors, highlighting attributes that are increasingly valued in the next‐generation devices, and summarizing the latest research addressing chemical modification of graphene and its derivatives for emerging capacitive energy storage applications.
Aqueous Zn batteries are promising for large-scale energy storage applications but are plagued by the lack of high-performance cathode materials that enable high specific capacity, ultrafast ...charging, and outstanding cycling stability. In this work, we design a laser-scribed nano-vanadium oxide (LNVO) cathode that can simultaneously achieve these properties. Our material stores charge through Faradaic redox reactions on/near the surface at fast rates owing to the small grain size (2-6 nm) of vanadium oxide and interpenetrating three-dimensional (3D) graphene network, displaying a surface-controlled capacity contribution (90%-98%). Multiple characterization techniques unambiguously reveal that zinc and hydronium ions co-insert with minimal LNVO lattice change upon cycling. As a result, we demonstrate that a high specific capacity of 553 mAh g
can be achieved by the LNVO/Zn system at 0.1 A g
and an impressive 264 mAh g
capacity can be retained at 100 A g
with a 10 s charge/discharge cycle, showing excellent rate capability. The LNVO/Zn is also capable of reaching >90% capacity retention after 3,000 cycles at a high rate of 30 A g
, as well as achieving both high energy (369 Wh kg
) and power densities (56,306 W kg
). Moreover, the LNVO cathode retains its excellent cycling performance when integrated into quasi-solid-state pouch cells, further demonstrating mechanical stability and its potential for practical application in wearable and grid-scale applications. This article is protected by copyright. All rights reserved.
The conducting polymer polyaniline (PANI) has been considered to be a promising pseudocapacitive electrode material for supercapacitors due to its high specific capacitance, low cost, and ...environmental friendliness. However, the poor cycling stability of PANI during the charge–discharge processes limits its widespread practical application. Herein, a facile synthetic method is demonstrated for covalently grafting an aniline tetramer (TANI), the basic building block of PANI, onto 3D graphene networks via perfluorophenylazide coupling chemistry to create a hybrid electrode material for ultralong‐life supercapacitors. The design, which substitutes long‐chain PANI with short‐chain TANI and introduces covalent linkages between TANI and 3D graphene, greatly enhances the charge–discharge cycling stability of PANI‐based supercapacitors. The electrode material, as well as the fabricated symmetric all‐solid‐state supercapacitors, exhibit extraordinary long cycle life (>85% capacitance retention after 30 000 charge–discharge cycles). The capacitance can be further boosted through fast and reversible redox reactions on the electrode surface using a redox‐active electrolyte while maintaining outstanding cycling stability (82% capacitance retention after 100 000 cycles for a symmetric all‐solid‐state device). While conducting polymers are known to be limited by their poor cycling stability, this work provides an effective strategy to achieve enhanced cycle life for conducting polymer‐based energy storage devices.
Through a one‐step solvothermal self‐assembly process, a facile “grafting to” approach via perfluorophenylazide coupling chemistry is demonstrated for the synthesis of a 3D graphene network with a covalently grafted aniline tetramer. The resulting electrode, as well as the fabricated symmetric supercapacitors, exhibit exceptional cycling stability, and a redox‐active electrolyte additive is further incorporated to boost the capacitance.
Mammalian Fuel Cells Produce Electric Current Shlosberg, Yaniv; Faynus, Mohamed A.; Huang, Ailun ...
ACS applied materials & interfaces,
07/2023, Letnik:
15, Številka:
29
Journal Article
Recenzirano
The increasing concern about climate change has led scientists around the world to develop clean energy technologies that may replace the traditional use of fossil fuels. A promising approach is the ...utilization of unicellular organisms as electron donors in bio-fuel cells. To date, this method has been limited to microorganisms such as bacteria, yeast, and microalgae. In this work, we show for the first time the concept of using mammalian cell cultures and organoids as electron donors in biofuel cells. We apply cyclic voltammetry to show that upon association of ARPE19 cells with the anode, they release reducing molecules to produce electricity. Furthermore, we apply 2D-fluorescence measurements and show that upon illumination, photosensitive stem cell-derived retinal organoids, which consist of rod photoreceptors and interneurons, secrete NADH and NADPH molecules that can donate electrons at the anode to produce photocurrent.
Supercapacitors have emerged as one of the leading energy‐storage technologies due to their short charge/discharge time and exceptional cycling stability; however, the state‐of‐the‐art energy density ...is relatively low. Hybrid electrodes based on transition metal oxides and carbon‐based materials are considered to be promising candidates to overcome this limitation. Herein, a rational design of graphene/VOx electrodes is proposed that incorporates vanadium oxides with multiple oxidation states onto highly conductive graphene scaffolds synthesized via a facile laser‐scribing process. The graphene/VOx electrodes exhibit a large potential window with a high three‐electrode specific capacitance of 1110 F g–1. The aqueous graphene/VOx symmetric supercapacitors (SSCs) can reach a high energy density of 54 Wh kg–1 with virtually no capacitance loss after 20 000 cycles. Moreover, the flexible quasi‐solid‐state graphene/VOx SSCs can reach a very high energy density of 72 Wh kg–1, or 7.7 mWh cm–3, outperforming many commercial devices. With Rct < 0.02 Ω and Coulombic efficiency close to 100%, these gel graphene/VOx SSCs can retain 92% of their capacitance after 20 000 cycles. The process enables the direct fabrication of redox‐active electrodes that can be integrated with essentially any substrate including silicon wafers and flexible substrates, showing great promise for next‐generation large‐area flexible displays and wearable electronic devices.
The vanadium oxides/graphene hybrid electrodes fabricated by a facile laser irradiation method have a high specific capacitance and a wide electrochemical window due to the presence of multiple vanadium oxidation states. The aqueous and gel symmetric supercapacitors based on the electrodes show high energy densities and power densities, excellent cycling stability and outstanding Coulombic efficiencies.
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