Co3O4 nanoparticles were readily obtained via thermal decomposition of cobalt oxalate nanorods precursor, which was synthesized by microemulsion-mediated solvothermal method. Experimental results revealed that the molar ratio of water to surfactant and the concentration of reactants played important roles in morphological control of CoC2O4 center dot 2H(2)O nanorods as well as Co3O4 nanoparticles. Catalytic activity of Co3O4 nanoparticles for methane combustion was also investigated. The results showed a high conversion efficiency (similar to 67%) at a lower temperature (350 degrees C) compared with bulk Co3O4, indicating a significant improvement for availability of the natural gas combustion and the removal of toxic gases. (C) 2009 Elsevier B.V. All rights reserved.