Mimicking the Microbial Oxidation of Elemental Sulfur with a Biphasic Electrochemical Cell

Abstract

The lack of an artificial system that mimics elemental sulfur (S 8 ) oxidation by microorganisms inhibits a deep mechanistic understanding of the sulfur cycle in the biosphere and the metabolism of sulfur-oxidizing microorganisms. In this article, we present a biphasic system that mimics biochemical sulfur oxidation under ambient conditions using a liquid|liquid (L|L) electrochemical cell and gold nanoparticles (AuNPs) as an interfacial catalyst. The interface between two solvents of very different polarity is an ideal environment to oxidise S 8 , overcoming the incompatible solubilities of the hydrophobic reactants (O 2 and S 8 ) and hydrophilic products (H + , SO 3 2– , SO 4 2– , etc. ). The interfacial AuNPs provide a catalytic surface onto which O 2 and S 8 can adsorb. Control over the driving force for the reaction is provided by polarizing the L|L interface externally and tuning the Fermi level of the interfacial AuNPs by the adsorption of aqueous anions.

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Identifiers

DOI

10.26434/chemrxiv.14153798.v1

Journal

ChemRxiv

Year

2021