Sub-10 nm Anisotropic Copper Oxide Nanowires for Electrochemical Sensing

G. Pathiraja, D. Herr, H. Rathnayake
University of North Carolina at Greensboro,
United States

Keywords: metal oxide nanowires, copper oxide, greener, oriented attachment, electrochemical


Anisotropic metal oxide nanowires with sub-nm regime open the door to exploit singular aspects of the 1D-electronic density states where electrochemical sensing performance can be improved by lowering detection potentials, and increasing current, enabling larger scale redox conversion, consequently increasing the analytical sensitivity. Bringing the dimensionality to sub-10 nm regime provides greater surface area with novel intrinsic features and functions different from the bulk material. Here, we demonstrate a novel, facile and greener fabrication method to make sub-10 nm copper oxide (CuO) nanowires using a directed self-assembly guided oriented attachment (OA) process under ambient conditions. We have performed in-situ monitoring of copper hydroxide (Cu(OH)2) nanocrystals self- assembly and growth under the transmission electron microscope to observe the OA crystal growth process to form ultrathin copper hydroxide nanowires, with diameter < 10 nm. High aspect ratio of 1D CuO nanowires were fabricated via post annealing of Cu(OH)2 nanowires. This surfactant free, one-pot sol-gel route at low temperature allows us to make CuO nanowires with controlled-dimensions in sub-10 nm regime over a large area. Further, the analysis of electrochemical properties of CuO nanowires have shown the suitability for potential electrochemical-based microfluidic analytical devices. Publications: • Gayani Pathiraja, Ryan Yarbrough, Hemali Rathnayake. (2020). Fabrication of ultrathin CuO nanowires augmenting oriented attachment crystal growth directed self-assembly of Cu (OH)2 colloidal nanocrystals, Nanoscale Advances, 2, 2897-2906.