Was H2O2 generated before oxygenic photosynthesis?

We obviously agree with Wu et al. that H2O2 might accumulate in the Archean land waters devoid of Fe2+. We do disagree on the topic of the half-life of H2O2, as the work cited in support for a longer half-live is not relevant to the conditions in the Archean ocean. While the existence of radicals in quartz is not in doubt, we do question the hypothesis that these radicals oxidize water to HO• and H2O2. The assay used by Wu et al. for the determination of H2O2 was not validated.