Highly Symmetrical Rh Nanonail Flowers

Abstract Uniform and well‐defined Rh nanonail flowers were successfully prepared by a facile solvothermal approach. The as‐prepared Rh nanonail flower with a crown diameter of about 90 nm consisted of twelve uniform nanonails originated from the same center with highly symmetrical distribution, in which each nanonail bounded with {111} facets was about 45 nm in length comprised of a pentaprism‐shaped nail stem of 10 nm in cross section and a pentapyramid‐shaped nail cap of 20 nm in diameter. The volume ratio of ethylamine (EA)/oleamine (OAm) was essential for the formation of the highly symmetrical Rh nanonail flowers. The selective adsorption of EA and OAm on (111) and (100) planes of the dodecahedral seeds, followed by the lateral epitaxial growth and the axial growth of pentagonal surfaces, drove to form the pentapyramid caps and pentaprism stems, respectively. The as‐prepared Rh nanonail flowers demonstrated significantly enhanced electrocatalytic activity and higher stability than commercial Rh black.