The Pechini process was modified to provide an ethanothermal reduction route to molybdenum dioxide microspheres at ambient temperature. The effects of citric acid (CA), ethylene glycol (EG), and H2SO4 environment on the formation of molybdenum oxide MoO2) were studied. Nanoparticles with the average diameter about several nanometers were also obtained through conventional method for comparison. These particles could be assembled into microspheres by introducing CA as complexing agent and EG as esterification agent. The advantage of the method, apart from its simplicity and operation at ambient conditions, is the ability to tailor the morphology and crystallinity of the product by varying the composition and sulfuric acid concentration from the precursor solution. (c) 2006 Elsevier B.V. All rights reserved.