Titania Nanotubes Decorated with Cu(I) and Cu(II) Oxides: Antibacterial and Ethylene Scavenging Functions To Extend the Shelf Life of Bananas

Abstract

Titanium nanotubes (TNTs) were prepared using TiO₂ and decorated with CuO and Cu₂O to have photocatalytic efficiency under visible light. TNTs decorated with copper oxides (TNT–CuO and TNT–Cu₂O) were confirmed by the elemental mapping and XPS results. Unlike TNT and TiO₂, TNT–CuO and TNT–Cu₂O showed higher photocatalytic activity, such as antimicrobial and ethylene scavenging activities under visible light. Between the two types of copper oxide-decorated TNTs, TNT–Cu₂O showed photocatalytic activity higher than that of TNT–CuO. The ethylene scavenging activity of TNT–Cu₂O was about 40% higher than that of TNTs and TNT–CuO. The photocatalytic activity of titanium-based nanoparticles was compared through fresh banana packaging. Bananas packaged with TiO₂ and TNTs showed higher weight loss and decreased firmness. In contrast, TNT–Cu₂O-packaged bananas maintained the fruit’s firmness, reduced weight loss, and delayed browning, maintaining the freshness for 7 days. TNT–Cu₂O is likely to be used as an effective ethylene scavenging material to extend the shelf life of fruits and vegetables.