An effective and green synthesis method for building photoluminescent molybdenum sub-oxide nanophase materials is reported. The method is based on plasma-enhanced hot filament chemical vapor deposition with N2 and MoO3 precursors. The microanalysis conformed that the nanomaterials are composed of MoO2 and Mo4O11 phases. Studies on formation mechanism indicate that the formation of different molybdenum oxide phases is the result of MoO3 reduction in different environments. The photoluminescence properties of molybdenum sub-oxide nanophase materials were studied at room temperature. The results reveal photoluminescence emission in a broad range from ultraviolet to infrared. This emission is attributed to electron transitions between the conduction and valence bands, between conduction and localized levels, and plasmon generation. These studies advance the knowledge of structural and optical properties of sub-stoichiometric molybdenum oxide nanomaterials and can contribute to the development of advanced optoelectronic devices.