Oxychlorine and Carbonate Generation by Simulated Electrostatic Discharge of Martian Dust Activities and Detection by Raman Spectroscopy

Abstract

The Martian atmosphere and surface materials can be impacted by electrochemical reactions that occur during dust activity on Mars. Prior research has shown that in the dry Martian surface environment, electrostatic discharge (ESD) can generate oxychlorine along with converting CO₂ to carbonate dust. To comprehend the carbon and chlorine cycles on Mars, research on carbonates and oxychlorine is crucial, as is investigating the effects of coexisting minerals. In support of this work, precise methods for measuring ESD reactions are needed. Herein, ESD reactions on chloride (NaCl) and potential coexisting minerals SiO₂ or TiO₂ were investigated under simulated Martian atmosphere conditions, and Raman spectroscopy was used to measure trace products. Based on Raman measurements, the influences of coexisting minerals on the production of carbonates and oxychlorine during ESD reactions were investigated. Our findings suggest that Raman spectroscopy has sensitive quantitative detection capabilities in aqueous solutions, offering a useful technique for the quantitative detection of laboratory products. Carbonate continuously accumulated with increasing discharge time, with 14–22 times greater yield (1.43–4.77‰ and 5% error) than perchlorate (0.10–0.24‰ and 20% error) and 5–16 times greater yield than chlorate (0.28–0.44‰ and 20% error). The yields of the above products were found to depend on the type, content, and particle size of coexisting minerals. Our findings are crucial for understanding the current geological history, atmospheric evolution, and substance cycling on Mars, as well as for retracing the development of Martian atmospheric and hydrological environments.