Nano-TiO2 photocatalytic device with applied polarization for on-demand oxidizing solution generation

Overview

This proposal describes a compact, flow-through device that generates an oxidizing disinfection solution on demand using a photocatalytic titanium dioxide (TiO2) surface combined with a small electrical current and light. The intended application is home and small-scale disinfection, where the device passes water or salt water across an illuminated, polarized TiO2 nanolayer to produce a solution containing active oxygen species or, when salt water is used, active chlorine species. By addressing the core limitation of conventional TiO2 photocatalysis, namely the rapid recombination of photogenerated electrons and holes, the design aims to make photocatalytic oxidation practical for consumer-scale water treatment.

Technical specifications

• Photocatalytic surface: A nano-sized titanium dioxide monolayer is formed on a conductive metal substrate to serve as the reactive interface.
• Charge separation mechanism: A small constant current source applies a positive polarization to the substrate, spatially separating photogenerated electrons (reducing side) from holes (oxidizing side) so that oxidizing species can accumulate in the flowing liquid.
• Light source: The TiO2 surface is photo-irradiated through a transparent glass layer using sunlight, enabling low-energy operation.
• Flow-through reactor geometry: A thin channel between the glass layer and the TiO2 surface allows water or salt water to flow across the active area, collecting the generated oxidizing solution.
• Dual-mode operation: The reactor can be operated with deionized water to produce a solution enriched in active oxygen, or with a NaCl solution to produce a solution containing active chlorine.
• Performance variables under study: Yield of the target oxidizing solution as a function of illumination intensity and applied polarization voltage.
• Form factor: Designed as a relatively small, quickly buildable device intended for home consumer use.

Technology readiness level

The hypothesis has not yet been experimentally validated. The research team is familiar with the individual steps required to fabricate the TiO2 nanolayer and to assemble the device, and estimates that a prototype reactor can be built and tested within approximately six months. Planned near-term validation includes fabricating the TiO2 nanolayer on a substrate, applying positive polarization through a constant current source, irradiating the surface with sunlight, and flowing water or salt water through the channel to characterize the resulting oxidizing solution in both deionized and NaCl modes. The current stage is best described as early-stage concept validation, with proof-of-concept prototyping as the next milestone before any assessment of commercial readiness.