Glucose Oxidation Performance of Zinc Nano-Hexagons Decorated on TiO2 Nanotube Arrays

Abstract

Electrochemically anodized TiO2 nanotube arrays (NTAs) were used as a support material for the electrodeposition of zinc nanoparticles. The morphology, composition, and crystallinity of the materials were examined using scanning electron microscopy (SEM). Electrochemical impedance spectroscopy (EIS) was performed to evaluate the electrochemical properties of TiO2 NTAs. Annealing post-anodization was shown to be effective in lowering the impedance of the TiO2 NTAs (measured at 1 kHz frequency). Zinc nanohexagons (NHexs) with a mean diameter of ~300 nm and thickness of 10–20 nm were decorated on the surface of TiO2 NTAs (with a pore diameter of ~80 nm and tube length of ~5 µm) via an electrodeposition process using a zinc-containing deep eutectic solvent. EIS and CV tests were performed to evaluate the functionality of zinc-decorated TiO2 NTAs (Zn/TiO2 NTAs) for glucose oxidation applications. The Zn/TiO2 NTA electrocatalysts obtained at 40 °C demonstrated enhanced glucose sensitivity (160.8 μA mM−1 cm−2 and 4.38 μA mM−1 cm−2) over zinc-based electrocatalysts reported previously. The Zn/TiO2 NTA electrocatalysts developed in this work could be considered as a promising biocompatible electrocatalyst material for in vivo glucose oxidation applications.