Enhanced electrochemical catalytic activity of new nickel hydroxide nanostructures with (100) facet

Owing to their scientific and technological importance, inorganic single crystals with highly reactive surfaces have long been studied. Unfortunately, surfaces with high reactivity usually diminish rapidly during the crystal growth process as a result of surface energy minimization. The crystal planes of nickel hydroxide play an essential role in determining its catalytic oxidation properties. In this study, β-Ni(OH)₂ nanocolumns with well-defined crystal planes have been synthesized by a facile solution-based hydrothermal method. TEM and XRD studies reveal that the assembled stacking of the Ni(OH)₂ nanocrystals leads to the predominantly exposed planes as unusually reactive (100) facet rather than the stable (001) facet in the hexagonal nanoslice structures. Consequently, it is demonstrated that the β-Ni(OH)₂ nanocolumns are more electrochemical catalytic active than their counterparts, nanoslices and nanoplates. The current study indicates that catalysts with well-defined reactive surface can be "designed" through controlled synthesis of nanostructures.