Electrochemical Decoration of Additively Manufactured Graphene Macroelectrodes with MoO₂ Nanowires: An Approach to Demonstrate the Surface Morphology

Abstract

Additive manufacturing (AM) provides a unique platform for the rapid design and fabrication of complex structures. Printed structures can be used as is or as templates to be decorated with electrochemical deposited nanomaterials, which may be utilised as electrocatalytic sensing platforms. Novel methods are required to determine the electrochemical deposited morphology present on the electrode surfaces. Additively manufactured graphene macroelectrodes (AM-GMs) were fabricated using a commercially available feedstock and molybdenum (di)oxide (MoO2) was successfully electrochemically deposited onto the electrode surface. The electrochemically deposited MoO2 was analysed using scanning electron microscopy (SEM), optical interferometry, Raman spectroscopy and multifractal analysis (MFA). Although the electrochemical deposition of MoO2 nanowires were clearly visible using SEM, MFA enabled quantification of the MoO2 nanowires, deposited at a variety of time points (20 -300 s). MFA was utilised to generate quantitative data, derived from ƒ(α) curves, to determine the area of the electrochemical deposited MoO2 nanowires, including coverage, density, dispersion and clustering. The AM-GMs which were subjected to 300 s (maximum time period) of MoO2 electrodeposition demonstrated the greatest percentage area coverage (20.14 %). The use of such mathematical systems offers an inexpensive method to characterise the parameters of electrochemically-deposited materials.

Diverse surface properties reveal that substratum roughness affects fungal spore binding

“…An MFA was carried out in a manner similar to that adopted in our earlier articles ( Wickens et al, 2014 ; Slate et al, 2020 ). MFA is typically used to measure the density, dispersion, and clustering of objects on a surface.…”

“…Both A. niger 1988 and A. pullulans were retained in the lowest numbers to the silicon surfaces (2.8 3 10 2 spores cm 2 and 1.9 3 10 2 spores cm 2 , respectively) (Figure 6C). An MFA was carried out in a manner similar to that adopted in our earlier articles (Wickens et al, 2014;Slate et al, 2020). MFA is typically used to measure the density, dispersion, and clustering of objects on a surface.…”

Effects of Cationic and Anionic Surfaces on the Perpendicular and Lateral Forces and Binding of Aspergillus niger Conidia

“…Two binary images and the corresponding multifractal f (α) curves are shown (Figure 1), where numerical measures of density D 0 , dispersion ∆α, and clustering ∆ f are also given. For a gentle introduction to fractals and multifractals, see [33]; for the mathematical theory behind multifractals, see [34]; and for a more detailed example in surface morphology, see [35].…”

Additive manufactured graphene-based electrodes exhibit beneficial performances in Pseudomonas aeruginosa microbial fuel cells

“…The AM-GMs electrodes have previously been characterised using Raman spectroscopy by [61]. The Raman spectra of the AM-GMs feature the characteristic carbonaceous peaks, commonly referred to as the G and 2D (G′) bands at ca.…”