Electrolytically generated size-tunable micro-nano bubbles toward high-efficiency antibacterial applications in...

Area of Science:

• Materials Science
• Environmental Science
• Biotechnology

Background:

• Bacterial contamination in water is a major global health concern.
• Micro-nano bubbles (MNBs) offer an efficient and eco-friendly antibacterial solution.
• Controlling MNB size is key to optimizing their disinfection efficacy.

Purpose of the Study:

• To develop size-tunable micro-nano bubbles (MNBs) for water disinfection.
• To establish a correlation between electrode structure and MNB characteristics.
• To elucidate the mechanism behind MNB-mediated bacterial inactivation.

Main Methods:

• Electrochemical fabrication of MNBs using TiO2 nanotube arrays (TNTAs).
• Tuning MNB size by controlling TNTAs pore diameter.
• Assessing antibacterial efficacy against E. coli and S. aureus.
• Investigating hydroxyl radical generation via mechanistic studies.

Main Results:

• A strong positive correlation (R² = 0.965) was found between TNTAs pore diameter and MNB size.
• Smaller MNBs demonstrated significantly higher bactericidal rates (98.8% for E. coli, 98.0% for S. aureus).
• Smaller MNBs generate higher concentrations of hydroxyl radicals (•OH) upon collapse.

Conclusions:

• Electrode pore size precisely controls MNB size, enabling tunable antibacterial properties.
• MNB size directly influences hydroxyl radical generation and antibacterial performance.
• This study provides a foundation for developing advanced, eco-friendly water disinfection technologies.