[en] Highlights: • Compared with earlier reported MoO₂ samples, our products have larger sizes and fine crystallinity. • Almost all reported methods to prepare MoO₂ flakes concern the reduction of MoO₃, here we show another non-reducing route based on disproportionation reaction. • Besides microflakes, MoO₂ nanorods were also found in samples for the first time. • The results of using different MoO_3−x precursors to prepare MoO₂ was studied. Experimental study on one evaporation process to deposit MoO₂ microflakes on SiO₂/Si substrate is reported. A chemical mechanism based on disproportionation reaction has been suggested and oxides MoO_3−x been found to be active precursors. As-prepared rhomboidal crystals have large sizes and high crystallinity, the size lengths of which can excess 200 μm and thicknesses of which are 20–100 nm. Uniform MoS₂ films can grow on their surfaces in suitable sulfuration process. The fine crystallinity, low evaporation rate and conductive property of these MoO₂ crystals make them potential alternative precursor/substrate for growth of 2D chalcogenides MoX₂ (X = S, Se, Te).