Photoelectrocatalytic tio2-based multi-radical oxidative purifying device for surface pathogen inactivation

Overview

This technology is a photoelectrocatalytic surface disinfection device built around a nanostructured black TiO2 material that generates multiple reactive radicals when activated by light and a low bias voltage. Designed in the form of a kitchen mop, the device creates a thin film of ion-containing water between the material and a contaminated surface, producing radicals that inactivate biological pathogens such as bacteria and viruses. By leveraging ions naturally present in tap water as the radical source material, the system achieves disinfection without requiring added chemical sanitizers.

The approach addresses the need for effective, chemical-free surface decontamination across settings including healthcare facilities, food preparation areas, laboratories, and consumer environments. Unlike traditional disinfection methods that rely on chemical agents, this device uses photocatalytic oxidation to neutralize pathogens on contact.

Technical specifications

Core technology:

• Nanostructured black TiO2 photoelectrocatalytic material engineered for visible-light absorption
• Multi-radical oxidative purifying (MOP) configuration integrated into a mop-style form factor
• Broad-spectrum light source surrounding a sheet of the black TiO2 material
• Low bias voltage (1 to 5 V) applied without causing water electrolysis due to existing overpotential in the TiO2 system
• Spray nozzle delivering a thin film of ion-containing solution (e.g., tap water) between the device and the target surface

Operating parameters validated in laboratory testing:

• Illumination at 25 mW/cm2 with increasing voltage progressively inactivates coliform bacteria
• Wavelengths of 405 nm and above combined with low bias voltages achieve full pathogen inactivation
• DPD (N,N-diethyl-p-phenylenediamine) dye measurements confirmed radical generation
• Initial validation demonstrated inactivation of coliform bacteria at concentrations of 2100 CFU/100 mL

Radical generation mechanism:

• Small amounts of chlorine and other ions naturally present in tap water serve as the source material for radical formation
• The combination of photoexcitation and applied bias drives the radical-generating reactions at the material surface

Technology readiness level

The technology is currently at an early-to-mid stage of development. The core black TiO2 photoelectrocatalytic material has been validated in a reactor configuration for water purification, demonstrating effective inactivation of coliform bacteria under controlled illumination and bias conditions. Published results confirm the relationship between light intensity, applied voltage, and pathogen inactivation efficacy.

Next-phase development will focus on two aims: first, synthesizing the nanostructured black TiO2 material and integrating it into a functional mop-like device with an integrated light source and spray nozzle; second, testing the device's effectiveness against a broader range of pathogens including E. coli, cryptosporidium, and avian coronavirus, with systematic exploration of exposure time and light intensity parameters. The device is not yet commercially available and requires prototype fabrication and expanded pathogen validation before market readiness.