SHORT COMMUNICATION Porous carbon and carbon composite hollow spheres Shujiang Ding & Chengliang Zhang & Xiaozhong Qu & Jiguang Liu & Yunfeng Lu & Zhenzhong Yang Received: 12 October 2007 / Revised: 22 December 2007 / Accepted: 7 March 2008 / Published online: 30 May 2008 # Springer-Verlag 2008 Abstract In this communication, we propose a template approach toward synthesis of carbon hollow spheres by direct carbonization of highly crosslinked sulfonated poly- styrene gel hollow spheres (sPS). The sulfonic acid group can facilitate carbonization. Moreover, the acid group can also induce a favorable growth of other materials within the sPS gel-forming carbon-based composite shell such as bi- continuous C/SiO 2 and their derivative ceramic SiC. Release of small molecules during polymers decomposition results porous shell. Keywords Carbon . Composite . Hollow spheres Introduction Hollow spheres and capsules have spurred great interest due to their broad applications [1–7]. Among these materials, hollow carbon spheres with shorter transportation pathway than their counterpart solid ones are in particular promising owning to their potential applications, such as catalyst supports [8] and anode materials in lithium secondary batteries [9]. Generally, hollow carbon spheres are synthesized by shock-compression technique [10], pyrolysis of a core-shell latex [11], solvothermal synthesis [12–14] which require rigorous conditions, expensive apparatus, or lack of structural control. It is, therefore, desired to develop a facile and scaleable method enabling the efficient synthesis of hollow carbon spheres. Recently, some novel methods have been developed for facile synthesis of mesoporous carbon hollow spheres such as by chemical vapor deposition or pyrolysis of polymer against mesoporous inorganic templates.[15–17] Both particle size and microstructure of the shell can be tuned. However, the shell may be easily fractured by the arisen osmotic pressure during the template removal. However, it is not easy to incorporate other functional materials within the carbon matrix especially in one step. The synthesis of hollow carbon and carbon nanocompo- site spheres. As schematically illustrated in Scheme 1, our synthesis strategy begins with sulfonated hollow polysty- rene spheres (sPS). Carbonization process catalyzed by the embedded sulfuric acid moiety (-SO 3 H) [18–20] converts the spheres into hollow carbon spheres. Small molecules released during this process create pores within the carbon shells and form a porous network. Meanwhile, various building components, such as metal ions and clusters of metal oxide, can be readily absorbed or grown within the sPS shells [21–24], which provides a simple and flexible approach to synthesize various carbon nanocomposite spheres in one step. As a proof of the concept, a sol–gel process of silica can be undertaken within the sPS shells to form hollow silica or sPS spheres. Carbonization and subsequent high temperature treatment convert the silica or sPS spheres into hollow carbon or silica nanocomposite spheres and crystalline SiC spheres, respectively. Different from the conventional core-shell based synthesis, the step Colloid Polym Sci (2008) 286:1093–1096 DOI 10.1007/s00396-008-1865-3 Electronic supplementary material The online version of this article (doi:10.1007/s00396-008-1865-3) contains supplementary material, which is available to authorized users. S. Ding : C. Zhang : X. Qu : J. Liu : Y. Lu : Z. Yang (*) State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China e-mail: yangzz@iccas.ac.cn Y. Lu(*) Department of Chemical and Biomolecular Engineering, University of California at Los Angeles, Los Angeles, CA 90095-1592, USA e-mail: luucla@ucla.edu