As shown in the literature, hexadecyltrimethylammonium bromide (CTAB) has been one of the most popular molecules for the preparation of Au and Ag nano-sized particles. In this work, we report a new sono-electrochemical pathway to prepare CTAB-capped micro-sized Au sheets in solutions. After complete removal of CTAB Au nanoparticles (NPs) were released from micro-sized Au sheets in solution, in which pH was reduced simultaneously. Therefore, enriched Au NPs can be controllably obtained from microsized Au sheets by increasing pH of solution. Experimental results indicate the particle sizes of released Au NPs with predominant (1 1 1) face is ca. 5 nm in diameter. Moreover, the catalytic activity of the prepared Au NPs was demonstrated by analyzing the decomposition of acetaldehyde in solution. (C) 2013 Elsevier B.V. All rights reserved,