An Aqueous Cooperative Assembly Route To Synthesize Ordered Mesoporous Carbons with Controlled Structures and Morphology

Abstract

A facile aqueous pathway has been demonstrated for the synthesis of ordered mesoporous carbon materials with hexagonal or cubic structures through the self-assembly of phenol/formaldehyde resols and triblock copolymer templates. Highly ordered mesoporous carbons FDU-16 with body-centered cubic structure (space group Im 3̄ m ) have been synthesized under a basic aqueous condition by using triblock copolymer Pluronic F127 (EO 106 PO 70 EO 106 ) as a template. Hydrocarbon (hexadecane or decane) can be used in the Pluronic P123 (EO 20 PO 70 EO 20 ) system as a swelling agent to synthesize highly ordered mesoporous carbons FDU-15 with 2-D hexagonal ( p 6 m ) structure. The pore size of FDU-15 can be tailored from 4.1 to 6.8 nm by simply varying the hydrocarbon molecules. Mesoporous carbon materials FDU-14 with bicontinuous cubic ( Ia 3̄ d ) structure can be formed at a P123/phenol molar ratio higher than 0.04. A phase transformation from Ia 3̄ d to p 6 m occurs as the P123/phenol ratio decreases. It is proposed that the cooperative assembly of resols and triblock copolymers driven by one-layer hydrogen bonds between the PEO segments and resols in aqueous solutions may favor the formation of mesostructures. Moreover, the morphology of the obtained mesoporous carbon materials can be controlled on the millimeter (1−5 mm) or micrometer (5−200 μm) scale. The simple aqueous route can give materials with a diversity of structures and morphologies, and this may offer the obtained materials very promising application prospects.