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Photoreduction of inorganic carbon(+IV) by elemental sulfur: Implications for prebiotic synthesis in terrestrial hot springs.

ABSTRACT: Terrestrial hydrothermal systems have been proposed as alternative birthplaces for early life but lacked reasonable scenarios for the supply of biomolecules. Here, we show that elemental sulfur (S0), as the dominant mineral in terrestrial hot springs, can reduce carbon dioxide (CO2) into formic acid (HCOOH) under ultraviolet (UV) light below 280 nm. The semiconducting S0 is indicated to have a direct bandgap of 4.4 eV. The UV-excited S0 produces photoelectrons with a highly negative potential of -2.34 V (versus NHE, pH 7), which could reduce CO2 after accepting electrons from electron donors such as reducing sulfur species. Simultaneously, UV light breaks sulfur bonds, benefiting the adsorption of charged carbonates onto S0 and assisting their photoreduction. Assuming that terrestrial hot springs covered 1% of primitive Earth's surface, S0 at 10 ?M could have produced maximal 109 kg/year HCOOH within 10-cm-thick photic zones, underlying its remarkable contributions to the accumulation of prebiotic biomolecules.

SUBMITTER: Li Y

PROVIDER: S-EPMC7673799 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature

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Photoreduction of inorganic carbon(+IV) by elemental sulfur: Implications for prebiotic synthesis in terrestrial hot springs.

Li Yanzhang Y Li Yan Y Liu Yi Y Wu Yifu Y Wu Junqi J Wang Bin B Ye Huan H Jia Haoning H Wang Xiao X Li Linghui L Zhu Meixiang M Ding Hongrui H Lai Yong Y Wang Changqiu C Dick Jeffrey J Lu Anhuai A

Science advances 20201118 47

Terrestrial hydrothermal systems have been proposed as alternative birthplaces for early life but lacked reasonable scenarios for the supply of biomolecules. Here, we show that elemental sulfur (S0), as the dominant mineral in terrestrial hot springs, can reduce carbon dioxide (CO2) into formic acid (HCOOH) under ultraviolet (UV) light below 280 nm. The semiconducting S0 is indicated to have a direct bandgap of 4.4 eV. The UV-excited S0 produces photoe ...[more]

PMID: 33208363

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Photoreduction of inorganic carbon(+IV) by elemental sulfur: Implications for prebiotic synthesis in terrestrial hot springs.

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Photoreduction of inorganic carbon(+IV) by elemental sulfur: Implications for prebiotic synthesis in terrestrial hot springs.

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