beta-Co(OH)(2) hollow-ware stacked nanosheets have been synthesized at low temperature (60 degrees C) through a simple surfactant-free technique. The factors on the formation of the hollowware-like stacked nanosheets have been studied and a possible formation mechanism is proposed. Thermally stable porous Co3O4 with the same morphology was prepared by thermal decomposition of the as-prepared Co(OH)(2). The catalytic properties of the porous Co3O4 and Au/Co3O4 are reported. (C) 2010 Elsevier B.V. All rights reserved.