Photocatalytic iron-doped titania nanoparticles for converting salt water into bleach

Overview

This solution is a photocatalytic nanoparticle material designed to generate sanitizing hypochlorite (bleach) directly from salt water using ordinary household visible light. The nanoparticles are composed of iron-doped titania, combining the visible-light photocatalytic activity of titania with the chloride-oxidation selectivity of iron oxide. The result is a non-toxic, environmentally safe system that eliminates the need for users to handle or purchase traditional bleach. Potential applications include household surface disinfection, food-safe sanitization, healthcare surface cleaning, and emergency water treatment in resource-limited settings.

Technical specifications

Key features:

• Iron-doped titania nanoparticles (10–30 nm) optimized for maximum surface area and high photocatalytic activity
• Solution-based microwave synthesis using solubilizing surfactants to tune composition, particle size, and aqueous dispersibility
• Visible-light activation, including blue LED illumination at household-relevant irradiance (400 nm)
• Selective oxidation of chloride ion to hypochlorite ion at neutral pH, with reported selectivity exceeding 98 percent in related iron oxide systems
• Rapid disinfection capability, with pollutant dye degradation half-lives on the order of 10 minutes under simulated solar light using milligram-scale catalyst loadings
• Aqueous dispersibility enabling easy application as a spray or wash solution

Technology readiness level

The underlying components have been individually validated: titania nanoparticles have been shown to degrade aromatic dye pollutants under visible light, iron oxide films have demonstrated greater than 98 percent efficiency for chloride-to-hypochlorite oxidation with no catalyst degradation over several hours, and microwave synthesis methods for active oxide photocatalysts have been established. Composition, phase, and particle size have been verified using X-ray diffraction, Raman and infrared spectroscopy, and electron microscopy. The current project aims to integrate these validated components into a single consumer-ready system, with a one-year validation timeline focused on iodometric titration measurements of hypochlorite generation rates under blue LED illumination. Partnership is sought to support chemical reagents, a dedicated microwave reactor, access to analytical instruments, and key personnel to conduct the work.