The unique electronic properties of graphene, a one atom thick carbon layer, were reported by scientists in 2004. Since this time graphene has subsequently been found to display several more unique ...and fascinating electrical, optical and mechanical properties. One particular area in which graphene has reportedly made an impact is in the field of electrochemistry, such as in providing enhancements in energy storage/generation and electrochemical sensing applications. Since 2005, when graphene was shown to be fabricated by the so-called 'Scotch tape technique' where multiple layers of graphene are peeled from a slab of Highly Ordered Pyrolytic Graphite using adhesive tape and transferred onto an appropriate substrate, other fabrication methodologies of graphene have emerged. In the majority of cases, graphene is produced and supplied in solution, such that graphene has to be immobilised onto the desired surface. A fabrication process where graphene is grown upon a substrate and is ready for implementation is the Chemical Vapour Deposition (CVD) of graphene. In this perspective article we overview recent developments in the fabrication of CVD graphene and explore its utilisation in electrochemistry, considering its fundamental understanding through to applications in sensing and energy related devices.
We overview recent developments in the fabrication of CVD graphene and explore its utilisation in electrochemistry, examining fundamental understandings through to applications in sensing and energy related devices.
The fabrication, characterization, and energy storage capacity of a graphene-oxide (GO)-based supercapacitor device is reported. This device is fabricated via a facile screen-printing technique, ...providing a highly reproducible and flexible symmetrical supercapacitor device. The capacitive properties of these GO devices are investigated in both aqueous electrolytes and room temperature ionic liquids. The GO devices are shown to improve the capacitive performance from 0.82 F g–1 displayed by a graphitic screen, to a competitive 423 F g–1, representing a ca. 500-fold increase. The GO supercapacitor device also exhibits an impressive power handling capability of up to 13.9 kW kg–1 and an energy density of 11.6 Wh kg–1. This work demonstrates that GO, before it has been reduced to graphene, is a high performance supercapacitor material of its own right.
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IJS, KILJ, NUK, PNG, UL, UM
We demonstrate that the “electrocatalytic” hydrogen peroxide detection reported at multiwalled carbon nanotube modified electrodes is due to iron oxide particles arising from the chemical vapor ...deposition nanotube fabrication process rather than due to intrinsic catalysis attributable to the carbon nanotubes arising, for example, from edge plane-like sites/defects.
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Creatinine, a molecule created within skeletal muscles as a product of work, is a widely studied molecule within the bioanalytical field, which can be used to reflect the state of renal and muscle ...function utilizing a range of known analytical techniques.
In this review the current analytical methods utilized for the quantification of creatinine are overviewed. After first exploring the biochemistry of creatinine, we then focus upon past and present analytical methodologies including high performance liquid chromatography, capillary electrophoresis and colourimetry for its sensing, and lastly diligently explore the electrochemical protocols used by scientists to detect creatinine and associated compounds, which include potentiometry, amperometry and microfluidic technologies.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
3D printing technology provides a unique platform for rapid prototyping of numerous applications due to its ability to produce low cost 3D printed platforms. Herein, a graphene-based polylactic acid ...filament (graphene/PLA) has been 3D printed to fabricate a range of 3D disc electrode (3DE) configurations using a conventional RepRap fused deposition moulding (FDM) 3D printer, which requires no further modification/ex-situ curing step. To provide proof-of-concept, these 3D printed electrode architectures are characterised both electrochemically and physicochemically and are advantageously applied as freestanding anodes within Li-ion batteries and as solid-state supercapacitors. These freestanding anodes neglect the requirement for a current collector, thus offering a simplistic and cheaper alternative to traditional Li-ion based setups. Additionally, the ability of these devices' to electrochemically produce hydrogen via the hydrogen evolution reaction (HER) as an alternative to currently utilised platinum based electrodes (with in electrolysers) is also performed. The 3DE demonstrates an unexpectedly high catalytic activity towards the HER (-0.46 V vs. SCE) upon the 1000th cycle, such potential is the closest observed to the desired value of platinum at (-0.25 V vs. SCE). We subsequently suggest that 3D printing of graphene-based conductive filaments allows for the simple fabrication of energy storage devices with bespoke and conceptual designs to be realised.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Crystalline 2D hexagonal boron nitride (2D-hBN) nanosheets are explored as a potential electrocatalyst toward the electroanalytical sensing of dopamine (DA). The 2D-hBN nanosheets are electrically ...wired via a drop-casting modification process onto a range of commercially available carbon supporting electrodes, including glassy carbon (GC), boron-doped diamond (BDD), and screen-printed graphitic electrodes (SPEs). 2D-hBN has not previously been explored toward the electrochemical detection/electrochemical sensing of DA. We critically evaluate the potential electrocatalytic performance of 2D-hBN modified electrodes, the effect of supporting carbon electrode platforms, and the effect of “mass coverage” (which is commonly neglected in the 2D material literature) toward the detection of DA. The response of 2D-hBN modified electrodes is found to be largely dependent upon the interaction between 2D-hBN and the underlying supporting electrode material. For example, in the case of SPEs, modification with 2D-hBN (324 ng) improves the electrochemical response, decreasing the electrochemical oxidation potential of DA by ∼90 mV compared to an unmodified SPE. Conversely, modification of a GC electrode with 2D-hBN (324 ng) resulted in an increased oxidation potential of DA by ∼80 mV when compared to the unmodified electrode. We explore the underlying mechanisms of the aforementioned examples and infer that electrode surface interactions and roughness factors are critical considerations. 2D-hBN is utilized toward the sensing of DA in the presence of the common interferents ascorbic acid (AA) and uric acid (UA). 2D-hBN is found to be an effective electrocatalyst in the simultaneous detection of DA and UA at both pH 5.0 and 7.4. The peak separations/resolution between DA and UA increases by ∼70 and 50 mV (at pH 5.0 and 7.4, respectively, when utilizing 108 ng of 2D-hBN) compared to unmodified SPEs, with a particularly favorable response evident in pH 5.0, giving rise to a significant increase in the peak current of DA. The limit of detection (3σ) is found to correspond to 0.65 μM for DA in the presence of UA. However, it is not possible to deconvolute the simultaneous detection of DA and AA. The observed electrocatalytic effect at 2D-hBN has not previously been reported in the literature when supported upon carbon or any other electrode. We provide valuable insights into the modifier–substrate interactions of this material, essential for those designing, fabricating, and consequently performing electrochemical experiments utilizing 2D-hBN and related 2D materials.
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IJS, KILJ, NUK, PNG, UL, UM
This manuscript details the first report of a complete additively manufactured rotating disk electrode setup, highlighting how high-performing equipment can be designed and produced rapidly using ...additive manufacturing without compromising on performance. The additively manufactured rotating disk electrode system was printed using a predominantly acrylonitrile butadiene styrene (ABS) based filament and used widely available, low-cost electronics, and simplified machined parts to create. The additively manufactured rotating disk electrode system costs less than 2% of a comparable commercial solution (£84.47 ($102.26) total). The rotating disk electrode is also additively manufactured using a carbon black/polylactic acid (CB/PLA) equivalent, developing a completely additively manufactured rotating disk electrode system. The electrochemical characterization of the additively manufactured rotating disk electrode setup was performed using hexaamineruthenium(III) chloride and compared favorably with a commercial glassy carbon electrode. Finally, this work shows how the additively manufactured rotating disk electrode experimental system and additive manufactured electrodes can be utilized for the electroanalytical determination of levodopa, a drug used in the treatment of Parkinson’s disease, producing a limit of detection of 0.23 ± 0.03 μM. This work represents a step-change in how additive manufacturing can be used in research, allowing the production of high-end equipment for hugely reduced costs, without compromising on performance. Utilizing additive manufacturing in this way could greatly enhance the research possibilities for less well-funded research groups.
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High-energy batteries need significant cathodes which can simultaneously provide large specific capacities and high discharge plateaus. NASICON-structured Na
3
V
2
(PO
4
)
3
(NVP) has been utilised ...as a promising cathode to meet this requirement and be used in the construction of high energy batteries. For a hybrid-ion battery by employing metallic lithium as an anode, NVP exhibits an initial specific capacity of 170 mA h g
−1
in the voltage range of 1.6-4.8 V with a long discharge plateau around 3.7 V. Three Na(2) sites for NVP are found capable to be utilised through the application of a wide voltage window but only two of them are able to undergo ions exchange to produce a NaLi
2
V
2
(PO
4
)
3
phase. However, a hybrid-ion migration mechanism is suggested to exist to describe the whole ion transport in which the effects of a Na-ion "barrier" results in a lowered ion diffusion rate and observed specific capacity.
A promising Na
3
V
2
(PO
4
)
3
cathode for use in the construction of high energy batteries is presented along the
b
axis based upon an improved solution-based carbothermal reduction method which is compared to a carbothermal reduction approach. A high capacity of 170 mA h g
−1
is produced with good C-rate and cycling performances.
•3D printing of a range of in-house fabricated graphite/PLA filaments.•Proof-of-concept shown with the simultaneous detection of lead(II) and cadmium(II).•Benchmarked electrochemical characterisation ...and analysis.
Additive manufacturing (AM)/3D printing technology provides a novel platform for the rapid prototyping of low cost 3D platforms. Herein, we report for the first time, the fabrication, characterisation (physicochemical and electrochemical) and application (electrochemical sensing) of bespoke nanographite (NG)-loaded (25 wt%) AM printable (via fused deposition modelling) NG/PLA filaments. We have optimised and tailored a variety of NG-loaded filaments and their AM counterparts in order to achieve optimal printability and electrochemical behaviour. Two AM platforms, namely AM macroelectrodes (AMEs) and AM 3D honeycomb (macroporous) structures are benchmarked against a range of redox probes and the simultaneous detection of lead (II) and cadmium (II). This proof-of-concept demonstrates the impact that AM can have within the area of electroanalytical sensors.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
2D hexagonal boron nitride (2D-hBN) is a lesser utilised material than other 2D counterparts in electrochemistry due to initial reports of it being
non-conductive
. As we will demonstrate in this ...review, this common misconception is being challenged, and researchers are starting to utilise 2D-hBN in the field of electrochemistry, particularly as the basis of electroanalytical sensing platforms. In this critical review, we overview the use of 2D-hBN as an electroanalytical sensing platform summarising recent developments and trends and highlight future developments of this interesting, often overlooked, 2D material.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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