Tuning peculiar antimony micro- and nano-morphology via a novel electrodeposition approach Xiaohu Huang ⁎ , Yonggang Zhu, Xincun Dou, Guanghai Li Key Laboratory of Material Physics, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei, 230031, PR China Received 30 March 2007; accepted 7 May 2007 Available online 22 May 2007 Abstract Antimony (Sb) microspheres composed of antimony nanoplates or nanoparticles were synthesized via a novel electrodeposition technique onto the top surface of porous anodic alumina membrane (AAM) after the growth of antimony nanowires. The two kinds of morphologies could be controlled by altering the experimental parameters, and the size of the nanoplates could also be tuned by adjusting the deposition potential. Besides, the micro- and nano-structure had relative narrow size distribution. Based on the experimental results, the possible growth mechanism was also proposed briefly. The method demonstrated here extends the application of AAM and can be used to synthesize other micro- and nano- structured materials. © 2007 Elsevier B.V. All rights reserved. Keywords: Antimony; Nanomaterials; Deposition; Anodic alumina membrane 1. Introduction Microscale materials which comprise nanoscale structures have attracted extensive interest in recent years, due to their peculiar properties and potential application in micro- and nano- devices [1]. It is generally believed that the properties of the micro- and nano-structures are strongly dependent on their shapes and sizes [2,3], so it is important to synthesize various materials with different morphologies. Sb is a semimetal with an energy overlap of 180 meV between the conduction and valence bands at 4.2 K. Due to its potential application in thermoelectric device, Sb nanowires aroused great interests in the past few years [4–6]. Sb microspheres have been prepared through hydrothermal method [7], but it involves both high temperature and high pressure. Two- dimensional nanomaterials have been paid much attention recently, because of its extensive application in biological, chemical and medical field [8]. To the best of our knowledge, there have been no reports yet on the synthesis of Sb nanoplates. Herein, we report a novel route to synthesize Sb microspheres composed of nanoplates in mild condition (at room temperature and atmospheric pressure) for the first time. 2. Experimental In a typical synthesis, AAM was prepared by a two-step anodization process as described in previous work [9]. First, high purity aluminum (99.999%) sheet was anodized at 40 V DC in 0.3 M oxalic acid electrolyte at 4 °C for 4 h, then the alumina layer produced was removed. The second anodization was conducted under the same conditions as the first one for 12 h. After the anodization, the central aluminum substrate was removed in a saturated SnCl 4 solution, and the alumina barrier layer was dissolved in 6 wt.% phosphoric acid solution at 30 °C for 60 min. Sb micro- and nano-structures were deposited from a solution similar to that previous used [6], which consisted of 0.02 M SbCl 3 , 0.1 M citric acid and 0.05 M kalium citrate. Pulsed electrodeposition was performed at potential U applied between graphite anode and AAM cathode in a common two-electrode glass plating cell at room temperature. The pulse cycle is 1200 μs, the ratio of pulse deposition time (T on ) vs. delay time (T off ) each pulse is abbreviated to R. The deposition was conducted for another long time after the overgrowth of nanowires, which we Available online at www.sciencedirect.com Materials Letters 62 (2008) 249 – 251 www.elsevier.com/locate/matlet ⁎ Corresponding author. Tel.: +86 551 5591465; fax: +86 551 5591434. E-mail address: xhhuang@issp.ac.cn (X. Huang). 0167-577X/$ - see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.matlet.2007.05.010