Optimised graphite/carbon black loading of recycled PLA for the production of low-cost conductive filament and its application to the detection of β-estradiol in environmental samples.

The production, optimisation, physicochemical, and electroanalytical characterisation of a low-cost electrically conductive additive manufacturing filament made with recycled poly(lactic acid) (rPLA), castor oil, carbon black, and graphite (CB-G/PLA) is reported. Through optimising the carbon black and graphite loading, the best ratio for conductivity, low material cost, and printability was found to be 60% carbon black to 40% graphite. The maximum composition within the rPLA with 10 wt% castor oil was found to be an overall nanocarbon loading of 35 wt% which produced a price of less than £0.

Exploring the Role of the Connection Length of Screen-Printed Electrodes towards the Hydrogen and Oxygen Evolution Reactions.

Zero-emission hydrogen and oxygen production are critical for the UK to reach net-zero greenhouse gasses by 2050. Electrochemical techniques such as water splitting (electrolysis) coupled with renewables energy can provide a unique approach to achieving zero emissions. Many studies exploring electrocatalysts need to "electrically wire" to their material to measure their performance, which usually involves immobilization upon a solid electrode.

The Voltammetric Detection of Cadaverine Using a Diamine Oxidase and Multi-Walled Carbon Nanotube Functionalised Electrochemical Biosensor.

Cadaverine is a biomolecule of major healthcare importance in periodontal disease; however, current detection methods remain inefficient. The development of an enzyme biosensor for the detection of cadaverine may provide a cheap, rapid, point-of-care alternative to traditional measurement techniques. This work developed a screen-printed biosensor (SPE) with a diamine oxidase (DAO) and multi-walled carbon nanotube (MWCNT) functionalised electrode which enabled the detection of cadaverine via cyclic voltammetry and differential pulse voltammetry.

2D-Hexagonal Boron Nitride Screen-Printed Bulk-Modified Electrochemical Platforms Explored towards Oxygen Reduction Reactions.

A low-cost, scalable and reproducible approach for the mass production of screen-printed electrode (SPE) platforms that have varying percentage mass incorporations of 2D hexagonal boron nitride (2D-hBN) (2D-hBN/SPEs) is demonstrated herein. These novel 2D-hBN/SPEs are explored as a potential metal-free electrocatalysts towards oxygen reduction reactions (ORRs) within acidic media where their performance is evaluated. A 5% mass incorporation of 2D-hBN into the SPEs resulted in the most beneficial ORR catalysis, reducing the ORR onset potential by ca.

Facile synthesis of Ni/NiO nanocomposites: the effect of Ni content in NiO upon the oxygen evolution reaction within alkaline media.

We present the facile synthesis of Ni/NiO nanocomposites, a solution combustion methodology, where the composition of metallic Ni within NiO is controlled by varying the annealing time, from 4 minutes up to 8 hours. The various Ni/NiO nanocomposites are studied electrically wiring them upon screen-printed graphite macroelectrodes by physical deposition. Subsequently their electrochemical activity, towards the oxygen evolution reaction (OER), is assessed within (ultra-pure) alkaline media (1.

Rapid antibiotic susceptibility testing using resazurin bulk modified screen-printed electrochemical sensing platforms.

Urinary tract infections (UTIs) are one of the most common types of bacterial infection. UTIs can be associated with multidrug resistant bacteria and current methods of determining an effective antibiotic for UTIs can take up to 48 hours, which increases the chances of a negative prognosis for the patient. In this paper we report for the first time, the fabrication of resazurin bulk modified screen-printed macroelectrodes (R-SPEs) demonstrating them to be effective platforms for the electrochemical detection of antibiotic susceptibility in complicated UTIs.

Recent advances in 2D hexagonal boron nitride (2D-hBN) applied as the basis of electrochemical sensing platforms.

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.

Platinum nanoparticle decorated vertically aligned graphene screen-printed electrodes: electrochemical characterisation and exploration towards the hydrogen evolution reaction.

We present the fabrication of platinum (Pt) nanoparticle (ca. 3 nm average diameter) decorated vertically aligned graphene (VG) screen-printed electrodes (Pt/VG-SPE) and explore their physicochemical characteristics and electrocatalytic activity towards the hydrogen evolution reaction (HER) in acidic media (0.5 M HSO).

Graphene Oxide Bulk-Modified Screen-Printed Electrodes Provide Beneficial Electroanalytical Sensing Capabilities.

We demonstrate a facile methodology for the mass production of graphene oxide (GO) bulk-modified screen-printed electrodes (GO-SPEs) that are economical, highly reproducible and provide analytically useful outputs. Through fabricating GO-SPEs with varying percentage mass incorporations (2.5%, 5%, 7.

Tailoring the electrochemical properties of 2D-hBN physical linear defects: physicochemical, computational and electrochemical characterisation.

Monolayer hexagonal-boron nitride films (2D-hBN) are typically reported within the literature to be electrochemically inactive due to their considerable band gap ( 5.2-5.8 eV).

Magnetron Sputter-Coated Nanoparticle MoS Supported on Nanocarbon: A Highly Efficient Electrocatalyst toward the Hydrogen Evolution Reaction.

The design and fabrication of inexpensive highly efficient electrocatalysts for the production of hydrogen via the hydrogen evolution reaction (HER) underpin a plethora of emerging clean energy technologies. Herein, we report the fabrication of highly efficient electrocatalysts for the HER based on magnetron-sputtered MoS onto a nanocarbon support, termed MoS/C. Magnetron sputtering time is explored as a function of its physiochemical composition and HER performance; increased sputtering times give rise to materials with differing compositions, i.

addition of graphitic carbon into a NiCoO/CoO composite: enhanced catalysis toward the oxygen evolution reaction.

We present a rapid, environmentally benign one-pot synthesis technique for the production of a NiCoO/CoO and graphite composite that demonstrates efficient electrocatalysis towards the Oxygen Evolution Reaction (OER), in 1.0 M KOH. The NiCoO/CoO/graphitic carbon composite that displayed optimal OER catalysis was synthesized by nitrate decomposition in the presence of citric acid (synthesized glycine and sucrose variants displayed inferior electro kinetics towards the OER).

Mass-producible 2D-WS bulk modified screen printed electrodes towards the hydrogen evolution reaction.

A screen-printable ink that contained varying percentage mass incorporations of two dimensional tungsten disulphide (2D-WS) was produced and utilized to fabricate bespoke printed electrodes (2D-WS-SPEs). These WS-SPEs were then rigorously tested towards the Hydrogen Evolution Reaction (HER) within an acidic media. The mass incorporation of 2D-WS into the 2D-WS-SPEs was found to critically affect the observed HER catalysis with the larger mass incorporations resulting in more beneficial catalysis.

Nanodiamond based surface modified screen-printed electrodes for the simultaneous voltammetric determination of dopamine and uric acid.

The electroanalytical detection of the neurotransmitter dopamine (DA) in the presence of uric acid (UA) is explored for the first time using commercially procured nanodiamonds (NDs). These are electrically wired via surface modification upon screen-printed graphite macroelectrodes (SPEs). The surface coverage of the NDs on the SPEs was explored in order to optimize electroanalytical outputs to result in well-resolved signals and in low limits of detection.

A facile electrochemical intercalation and microwave assisted exfoliation methodology applied to screen-printed electrochemical-based sensing platforms to impart improved electroanalytical outputs.

Screen-printed electrodes (SPEs) are ubiquitous with the field of electrochemistry allowing researchers to translate sensors from the laboratory to the field. In this paper, we report an electrochemically driven intercalation process where an electrochemical reaction uses an electrolyte as a conductive medium as well as the intercalation source, which is followed by exfoliation and heating/drying via microwave irradiation, and applied to the working electrode of screen-printed electrodes/sensors (termed EDI-SPEs) for the first time. This novel methodology results in an increase of up to 85% of the sensor area (electrochemically active surface area, as evaluated using an outer-sphere redox probe).

Mass-Producible 2D-MoS-Impregnated Screen-Printed Electrodes That Demonstrate Efficient Electrocatalysis toward the Oxygen Reduction Reaction.

Two-dimensional molybdenum disulfide (2D-MoS) screen-printed electrodes (2D-MoS-SPEs) have been designed, fabricated, and evaluated toward the electrochemical oxygen reduction reaction (ORR) within acidic aqueous media. A screen-printable ink has been developed that allows for the tailoring of the 2D-MoS content/mass used in the fabrication of the 2D-MoS-SPEs, which critically affects the observed ORR performance. In comparison to the graphite SPEs (G-SPEs), the 2D-MoS-SPEs are shown to exhibit an electrocatalytic behavior toward the ORR which is found, critically, to be reliant upon the percentage mass incorporation of 2D-MoS in the 2D-MoS-SPEs; a greater percentage mass of 2D-MoS incorporated into the 2D-MoS-SPEs results in a significantly less electronegative ORR onset potential and a greater signal output (current density).

3D Printed Graphene Based Energy Storage Devices.

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.

Defining the origins of electron transfer at screen-printed graphene-like and graphite electrodes: MoO2 nanowire fabrication on edge plane sites reveals electrochemical insights.

Molybdenum (di)oxide (MoO2) nanowires are fabricated onto graphene-like and graphite screen-printed electrodes (SPEs) for the first time, revealing crucial insights into the electrochemical properties of carbon/graphitic based materials. Distinctive patterns observed in the electrochemical process of nanowire decoration show that electron transfer occurs predominantly on edge plane sites when utilising SPEs fabricated/comprised of graphitic materials. Nanowire fabrication along the edge plane sites (and on edge plane like-sites/defects) of graphene/graphite is confirmed with Cyclic Voltammetry, Scanning Electron Microscopy (SEM) and Raman Spectroscopy.

2D molybdenum disulphide (2D-MoS2) modified electrodes explored towards the oxygen reduction reaction.

Two-dimensional molybdenum disulphide nanosheets (2D-MoS2) have proven to be an effective electrocatalyst, with particular attention being focused on their use towards increasing the efficiency of the reactions associated with hydrogen fuel cells. Whilst the majority of research has focused on the Hydrogen Evolution Reaction (HER), herein we explore the use of 2D-MoS2 as a potential electrocatalyst for the much less researched Oxygen Reduction Reaction (ORR). We stray from literature conventions and perform experiments in 0.

2D nanosheet molybdenum disulphide (MoS2) modified electrodes explored towards the hydrogen evolution reaction.

We explore the use of two-dimensional (2D) MoS2 nanosheets as an electrocatalyst for the Hydrogen Evolution Reaction (HER). Using four commonly employed commercially available carbon based electrode support materials, namely edge plane pyrolytic graphite (EPPG), glassy carbon (GC), boron-doped diamond (BDD) and screen-printed graphite electrodes (SPE), we critically evaluate the reported electrocatalytic performance of unmodified and MoS2 modified electrodes towards the HER. Surprisingly, current literature focuses almost exclusively on the use of GC as an underlying support electrode upon which HER materials are immobilised.