Shape Control of Cobalt Carbonate Particles by a Hydrothermal Process in a Mixed Solvent: An Efficient Precursor to Nanoporous Cobalt Oxide Architectures and Their Sensing Property

Shape-controlled synthesis of CoCO 3 crystals has been achieved by a hydrothermal process in a mixed solvent of water and ethanol (or glycerol). Uniform CoCO 3 crystals with novel structures can be fabricated by tuning the volume ratio of water and ethanol (or glycerol). The results demonstrated that the as-prepared CoCO 3 crystal can act as an efficient precursor for production of nanoporous Co 3 O 4 particles with pore sizes of 2.5 and 60 nm by calcination at 500 °C. The nanoporous Co 3 O 4 particles show sensitive response and reversibility in sensing performance.