Preparation of mesoporous carbon aerogels via ambient pressure drying using a self-sacrificing melamine-formaldehyde template

Abstract

In order to overcome the pore collapse phenomenon during the ambient pressure drying and subsequent carbonization processes, we propose herein a new strategy of preparing mesoporous carbon aerogel (MeCA) based on a sol–gel polymerization method coupling with two key steps of introducing the self-sacrificing melamine-formaldehyde template (MF) and carefully adjusting the heating rate of the carbonization. The solid-state MF substituting the liquid-state solvent in the pores of organic wet gel effectively alleviates the capillary pressure, preventing the mesopores from collapse during ambient pressure drying, and then decomposes into gases slowly during the modified carbonization process. As a result, the obtained MeCA with the slimmest skeleton demonstrates a pore volume of 0.82 cm3 g−1, a surface area of 534 m2 g−1 and a well-retained mesoporous structure with a pore size of 11 nm. This value of the mesopore size, to our knowledge, is the smallest one of the ever reported MeCAs prepared by ambient pressure drying. We believe that this approach may open the doors for the preparation of carbon aerogels with desired nanostructure for numerous applications.