Premium
Nanoparticles of Mesoporous SO 3 H‐Functionalized Si‐MCM‐41 with Superior Proton Conductivity
Author(s) -
Marschall Roland,
Bannat Inga,
Feldhoff Armin,
Wang Lianzhou,
Lu Gao Qing Max,
Wark Michael
Publication year - 2009
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.200801235
Subject(s) - mesoporous material , materials science , surface modification , nanoparticle , conductivity , chemical engineering , proton , mesoporous silica , particle (ecology) , micrometer , particle size , nanotechnology , organic chemistry , chemistry , catalysis , physics , oceanography , optics , quantum mechanics , geology , engineering
Nanometer‐sized mesoporous silica particles of around 100‐nm diameter functionalized with a large amount of sulfonic acid groups are prepared using a simple and fast in situ co‐condensation procedure. A highly ordered hexagonal pore structure is established by applying a pre‐hydrolysis step in a high‐dilution synthesis approach, followed by adding the functionalization agent to the reaction mixture. The high‐dilution approach is advantageous for the in situ functionalization since no secondary reagents for an effective particle and framework formation are needed. Structural data are determined via electron microscopy, nitrogen adsorption, and X‐ray diffraction, proton conductivity values of the functionalized samples are measured via impedance spectroscopy. The obtained mesoporous SO 3 H‐MCM‐41 nanoparticles demonstrate superior proton conductivity than their equally loaded micrometer‐sized counterparts, up to 5 × 10 −2 S cm −1 . The mesoporosity of the particles turns out to be very important for effective proton transport since non‐porous silica nanoparticles exhibit worse efficient proton transport, and the obtained particle size dependence might open up a new route in rational design of highly proton conductive materials.