A one-pot hydrothermal synthesis strategy for MoS2 is developed that allows to simultaneously control both the crystallite size and geometric nanoconfinement environment (i.e., interlayer distance and guest species density) of the material. Pristine MoS2 is obtained following a hydrothermal process outlined by X. Geng et al., and the particle size is controlled by adjusting the pH of the precursor solution, with more acidic conditions yielding