An Electrochemical System for Gaseous ClO₂ Generation Using TiO₂ Nanorod Array Cathodes Toward Fruit Preservation

Area of Science:

• Electrochemistry
• Materials Science
• Food Science

Background:

• Efficient on-demand generation of chlorine dioxide (ClO2) is crucial for disinfection and food preservation.
• Current methods for gaseous ClO2 production face challenges in safety and efficiency.

Purpose of the Study:

• To develop a stable and efficient electrochemical system for ClO2 production.
• To investigate the mechanism and optimize conditions for ClO2 generation.
• To evaluate the disinfection and food preservation efficacy of the generated ClO2.

Main Methods:

• Utilized rutile titanium dioxide nanorod arrays (TiO2 NAs) as cathodes in an electrochemical system.
• Optimized cathodic potential and electrolyte composition (1 M NaClO3, 5 M H2SO4).
• Investigated the reaction mechanism involving oxygen reduction and in situ hydrogen peroxide formation.
• Decorated TiO2 NAs with ruthenium oxide (RuOx) nanoparticles to enhance performance.
• Assessed antibacterial activity against Escherichia coli and Staphylococcus aureus.
• Evaluated preservation effects on longan fruit over 8 days.

Main Results:

• Achieved highest ClO2 production efficiency at -0.10 V (vs. Ag/AgCl).
• Identified an O2-induced pathway where electrogenerated H2O2 reacts with ClO3- to form ClO2, improving safety.
• RuOx-decorated TiO2 NA cathodes showed enhanced catalytic activity and stability.
• Demonstrated >99% antibacterial efficiency against E. coli and S. aureus.
• Showcased significant reduction in weight loss and preserved hardness in stored longan fruit.

Conclusions:

• Developed a safe and efficient electrochemical system for on-demand ClO2 generation using TiO2 NAs.
• The O2-induced pathway eliminates the need for external H2O2, enhancing operational safety.
• The system shows strong potential for practical applications in food preservation and disinfection.