ISO 19722:2017

Overview

ISO 19722:2017 specifies a laboratory test method to determine photocatalytic activity of semiconducting photocatalytic materials by measuring dissolved oxygen (DO) consumption. The method quantifies oxygen consumed during photocatalytic oxidation of phenol in aqueous solution as an indicator of mineralization activity. It applies to powder test samples and film test pieces of semiconducting photocatalysts (e.g., titanium dioxide-based fine ceramics) targeting water contaminants, but it excludes materials conjugated with organic binders that themselves decompose under photocatalysis.

Key topics and technical requirements

• Principle: Photocatalytic oxidation of organic pollutants consumes dissolved O2; measuring DO decrease gives photocatalytic oxygen demand (POD) as an activity metric.
• Test materials: Phenol reagent (>99 wt%) as the probe organic; purified/distilled water; purified air; DO-saturated water for conditioning.
• Sample types: Powder suspensions and immersed film test pieces; separate preparation and measurement procedures for each.
• Apparatus:
  • Ultraviolet (UV) irradiation source - black light lamps (BL / BLB) with peak wavelength ~351 nm (per ISO 10677).
  • UV radiometer calibrated to the lamp spectral response.
  • DO analyser and DO electrode for continuous DO measurement.
  • Magnetic stirrer, specified test vessels and implements described in annexes.
• Test procedure: Controlled temperature and UV exposure, blank tests (blank POD(%)), measurement sequences for dark and irradiated conditions, and calculation of POD.
• Evaluation & reporting: Standardized reporting requirements and example data treatment are provided; interlaboratory results and informative annexes support reproducibility.

Practical applications - who uses ISO 19722

• Research and development teams evaluating new semiconducting photocatalysts and coatings for water treatment.
• Quality control laboratories assessing batch-to-batch photocatalytic performance of powders and films.
• Accredited testing labs (ISO/IEC 17025) performing comparative activity measurements for manufacturers of fine ceramics and photocatalytic materials.
• Product development for water purification, self‑cleaning surfaces, antimicrobial coatings, and environmental remediation where aqueous-phase photocatalysis is relevant.

Related standards

• ISO 10677 - Ultraviolet light source for testing semiconducting photocatalytic materials (lamp characteristics).
• ISO 5814 - Determination of dissolved oxygen (electrochemical probe method).
• ISO/IEC 17025 - Laboratory competence requirements (applicable for accredited testing).

ISO 19722:2017 is a practical, reproducible method for quantifying photocatalytic oxidation capacity in the aqueous phase using DO consumption and is especially useful for comparing semiconducting photocatalysts in R&D and quality assurance workflows.