An abiotic source of Archean hydrogen peroxide and oxygen that pre-dates oxygenic photosynthesis

Hydrogen peroxide (H2O2) has been proposed as an electron donor for photosynthesis before water, however, the amount of H2O2 available on early Earth was thought to be limited. Here the authors propose a new abiotic pathway wherein abrasion of quartz surfaces would have provided enough H2O2. The evolution of oxygenic photosynthesis is a pivotal event in Earth's history because the O-2 released fundamentally changed the planet's redox state and facilitated the emergence of multicellular life. An intriguing hypothesis proposes that hydrogen peroxide (H2O2) once acted as the electron donor prior to the evolution of oxygenic photosynthesis, but its abundance during the Archean would have been limited. Here, we report a previously unrecognized abiotic pathway for Archean H2O2 production that involves the abrasion of quartz surfaces and the subsequent generation of surface-bound radicals that can efficiently oxidize H2O to H2O2 and O-2. We propose that in turbulent subaqueous environments, such as rivers, estuaries and deltas, this process could have provided a sufficient H2O2 source that led to the generation of biogenic O-2, creating an evolutionary impetus for the origin of oxygenic photosynthesis.

Automated summary

Researchers propose a new theory that abrasion of quartz surfaces in the early Earth could have provided enough hydrogen peroxide for photosynthesis to serve as an electron donor; the evolution of oxygenic photosynthesis is significant in Earth's history, as the released oxygen fundamentally changed the planet's redox state and facilitated the emergence of multicellular life.