Facile synthesis of B-MCM-41 with controlled morphologies using water–acetone media Jinchang Zhang a , Min Liu a , Chunshan Song a,b,⇑ , Xinwen Guo a,⇑ a State Key Laboratory of Fine Chemicals, Department of Catalysis Chemistry and Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116012, PR China b EMS Energy Institute, Department of Energy and Mineral Engineering, The Pennsylvania State University, University Park, PA 16802, USA article info Article history: Received 25 May 2010 Received in revised form 10 October 2010 Accepted 12 October 2010 Available online 19 October 2010 Keywords: B-MCM-41 Water–acetone Controlled morphologies Nanorod Nanosphere abstract B-MCM-41 nanoparticles with controlled morphologies including nanorods and nanospheres have been synthesized in water–acetone media using cetyltrimethylammonium bromide (CTAB) as the template and boric acid as boron source. It was found that the total boron content in the product increases with reducing both the water-to-acetone molar ratios in the synthesis gel and hydrothermal temperature. The framework boron content rises with the increase in the hydrothermal temperature. From transmis- sion electron microscopy (TEM) images, it was observed that mesoporous parallel channels run along the long axis in major areas in the nanorods, whereas the radially arranged mesopore channels are present in the nanospheres. Additionally, hydrothermal treatment leads to rougher surfaces while retaining the morphologies and nanostructures of these boron-containing mesoporous silicas. Ó 2010 Elsevier Inc. All rights reserved. 1. Introduction Since the synthesis of the crystalline mesoporous M41S materi- als by Mobil researchers [1,2], many subsequent studies have fo- cused on the MCM-41 material possessing unidirectional, channel-like pores of uniform size which are arranged in a regular hexagonal pattern. Their extraordinary high surface area and dis- tinct adsorption properties opened up many potential applications in catalysis, separation and nanostructured materials [3–5]. There is no doubt that the presence of these very large pores combined with acidic properties opens up new possibilities for processing and/or producing large molecules. Incorporation of foreign atoms in the framework of silica-based MCM-41 such as Al [6], Ga [7], Ti [8],V [9],B [10–13] has been reported. The substitution of Si by B during the synthesis of MCM-41 is ex- pected to modify the acidic properties of these materials and there- by their catalytic properties. Regarding the borosilicate mesoporous molecular sieves, Oberhagemann et al. [14] used a single silica source, tetramethoxy silane, whereas Trong On et al. [15] took lu- dox and sodium silicate to synthesize B-MCM-41. It was found [16] that the borosilicate molecular sieves in which boron occupies the site of the framework aluminium and the protonic form of boro- silicate molecular sieves, are less acidic than their aluminosilicate counterparts due to lack of strong Brönsted acidity. In the literature few reports are available on synthesis of spherical B-MCM-41; therefore it is still a challenge to control the morphology by simply changing composition parameter of the synthetic solutions. Herein, we report a facile synthesis of B-MCM-41 materials with controlled morphologies using cetyltrimethylammonium bromide (CTAB) as the template, H 3 BO 3 as boron source, and the ammo- nia-catalyzed hydrolysis of TEOS in water–acetone at room temper- ature. It was found that the morphology of the obtained B-MCM-41 can be readily controlled in the shape of nanorods and nanospheres by simply adjusting the water-to-acetone molar ratio. 2. Experimental 2.1. Materials CTAB (99 wt.%) and TEOS (99.9 wt.%) were obtained from Tian- jin Fine Chemical Institute. Boric acid (H 3 BO 3 ) was provided by Tianjin No. 3 Chemical Reagent Factory. Ammonia solution (NH 4 OH) (25–28 wt.%) was purchased from Shantou Xilong Chem- ical Reagent Factory and acetone was from Shenyang Federal Re- agent Factory. All chemicals are analytical grade and were used without further purification. 2.2. Synthesis The synthesis of mesoporous B-MCM-41 was achieved by the ammonia-catalyzed hydrolysis of TEOS in a mixed solvent of water 1387-1811/$ - see front matter Ó 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.micromeso.2010.10.012 ⇑ Corresponding authors. Address: EMS Energy Institute, Department of Energy and Mineral Engineering, The Pennsylvania State University, University Park, PA 16802, USA (C. Song). Tel.: +86 411 88993994; fax: +86 411 88993991 (X. Guo). E-mail addresses: csong@psu.edu (C. Song), guoxw@dlut.edu.cn (X. Guo). Microporous and Mesoporous Materials 139 (2011) 31–37 Contents lists available at ScienceDirect Microporous and Mesoporous Materials journal homepage: www.elsevier.com/locate/micromeso