Modulation of Photoluminescence of Monolayer MoS$_{\mathrm{2}}$

Modulation of photoluminescence (PL) of two-dimensional materials is important for its optoelectronic and catalysis applications. We have systematically studied the effect of thermal and photo-reaction of various ambient molecules (H$_{\mathrm{2}}$O, O$_{\mathrm{2}}$, and N$_{\mathrm{2}})$ on the photoluminescence of CVD grown monolayer MoS$_{\mathrm{2}}$. The results show that the photoreaction of the O$_{\mathrm{2}}$ with MoS$_{\mathrm{2}}$ monolayer can affect the PL intensity. For the application of desulfurization of gasoline, we compared the difference in the interaction of pyridine molecules with monolayer MoS$_{\mathrm{2}}$. Our results show that liquid pyridine and gaseous pyridine interact differently with MoS$_{\mathrm{2}}$ monolayers.