Ultrafast epitaxial growth of CuO nanowires using atmospheric pressure plasma with enhanced electrocatalytic and photocatalytic activities

Abstract

This work reports an environment friendly alternative to epitaxially grow copper oxide nanowires (NWs) on copper substrates using single step atmospheric pressure plasma jet assisted oxidation. NWs of average length 300 nm are grown rapidly in 5 minutes along with transforming the surface to superhydrophilic. This method introduces defects in the nanowire structure which is otherwise difficult to achieve due to the highly isotropic nature of nanowire growth. High resolution transmission electron microscopy reveals vacancies and structural defects such as lattice twinning and kinks. Theoretical investigations using density functional theory calculations indicated that oxygen vacancies reduces the adsorption energy of methanol molecules onto the CuO (111) surface and shifts the Fermi level towards conduction band. During electrocatalysis, these defect-rich nanowires exhibit twice the catalytic activity toward oxygen evolution reaction (OER) and methanol oxidation reaction (MOR) in comparison to the traditionally thermally grown nanowires. Moreover, retreating the electrodes after each stability test drops the contact resistance similar to the prisitine sample. Additionally, these NW photocathodes demonstrate an exceptional photocurrent of 2.2 mAcm -2 and have an excellent degradation activity towards organic pollutants namely phenol and paracetamol. This facile growth method can be used to engineer nanowires of other transition metals with enhanced activities.

Ultrafast materials synthesis and manufacturing techniques for emerging energy and environmental applications

“…Ultrafast synthesis techniques also have not demonstrated high-resolution (sub-nm) spatially resolved materials, yet they are possible and highly desired in applications such as catalysis. [240][241][242] A versatile choice of materials can be synthesized with future highly spatial and temporal resolved ultrafast synthesis techniques. The scalable production (in kilograms or tons) of highly precise materials (in terms of microstructures and resolutions) is also challenging but of vital importance to a broader application of ultrafast manufacturing.…”

Recent Advances in Synthesis, Modification, Characterization, and Applications of Carbon Dots

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