Synthesis of BaMo$_{\mathrm{3}}$ from Colloidal MoS$_{\mathrm{2}}$

MoS$_{\mathrm{2}}$ is typically considered to be a highly stable structure, but we have found that it spontaneously reacts with aqueous solutions containing Ba$^{\mathrm{2+}}$ to generate BaMoO$_{\mathrm{4}}$. This reaction occurs rapidly when the MoS$_{\mathrm{2}}$ is first exfoliated into nanoparticulate plates. In this study we investigate the oxidizing agent in this reaction, the fate of sulfur, and how the pH of the solution affects the production of BaMoO$_{\mathrm{4}}$. The reaction was found to be most efficient at high pH indicating that hydroxide may be involved in the mechanism. Inert atmosphere conditions and non-oxidizing anions were used to determine that water is the oxidizing agent. H$_{\mathrm{2}}$S was found in the product using GC-MS, implying that sulfur leaves as S$^{\mathrm{2-}}$.