Monodispersed Cu-2(OH)(3)Cl nanoplatelets, Cu(OH)(2) nanowires, CuO nanoparticles and nanoribbons with a spherical morphology were synthesized using hydrothermal and heat-treatment reactions, and their H-2 storage characteristics were examined. The Cu-2(OH)(3)Cl nanoplatelets particles formed immediately after mixing the reactant, which subsequently formed larger uniform spherical particles in the submicron range. This procedure highlights a practical strategy for producing spherical Cu(OH)2 and CuO materials consisting of monodispersed nanocrystals. The spherical aggregates of Cu-2(OH)(3)Cl nanoplatelets heat-treated at 473 K could reversibly store up to 2.35 wt.% H-2 at 38 bar and 293 K. (c) 2006 Elsevier B.V. All rights reserved.