Vacuum ultraviolet photodissociation of sulfur dioxide and its implications for oxygen production in the early Earth's atmosphere.

ABSTRACT: The emergence of molecular oxygen (O₂) in the Earth's primitive atmosphere is an issue of major interest. Although the biological processes leading to its accumulation in the Earth's atmosphere are well understood, its abiotic source is still not fully established. Here, we report a new direct dissociation channel yielding S(¹D) + O₂(a¹Δ_g/X³Σ_g^-) products from vacuum ultraviolet (VUV) photodissociation of SO₂ in the wavelength range between 120 and 160 nm. Experimental results show O₂ production to be an important channel from SO₂ VUV photodissociation, with a branching ratio of 30 ± 5% at the H Lyman-α wavelength (121.6 nm). The relatively large amounts of SO₂

SUBMITTER: Chang Y 

PROVIDER: S-EPMC10411858 | biostudies-literature | 2023 Aug

REPOSITORIES: biostudies-literature