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.