Spontaneous hydrogen peroxide formation in pure water microdroplets
In plain words
Some experiments report that spraying pure water into tiny droplets makes hydrogen peroxide with no added chemicals. Other experiments trace the peroxide to ozone from air or to contact with surfaces.
Precise statement
For water microdroplets of radius 1 to 20 micrometers produced by spraying or condensation in an oxygen-free and ozone-free atmosphere, determine whether H2O2 forms at concentrations above 1 micromolar from water oxidation at the interface. An answer is a yes or no from controlled experiments that exclude dissolved oxygen, ozone, electrode and solid-contact sources, together with the energy source if yes.
What would settle it
Isotope-labeled (H2 18O) experiments in rigorously controlled atmospheres with independent quantification of peroxide.
Status in the literature
Unverified note
Since the 2019 report, claims and counterclaims have attributed the peroxide to interfacial fields, contact electrification or ambient ozone; contested as of 2024 (not rechecked for 2025-2026).