Template synthesis of mesoporous carbons with a controlled particle size

Abstract

Mesostructured silica materials synthesised with the aid of surfactants as structure directing agents were used as templates to fabricate mesoporous carbons. By modifying the operational parameters during the synthesis, the particle size of silica can be continuously modulated from nanometric particles (∼10–20 nm) to micrometric spherical particles (∼2–8 µm). The porous carbons fabricated by using the mesostructured silica as template maintain the size and shape of the template. In this way, the primary particle size of the obtained porous carbons can be easily selected in a wide range between 10 nm and 10 µm by using the appropriate silica template. These carbons exhibit large pore volumes (>1.4 cm³ g⁻¹), large BET surface areas (>1800 m² g⁻¹) and a porosity made up of pores with sizes in the mesopore range. The micrometric carbon shows a perfectly spherical morphology and a unimodal pore system made up of structural mesopores of ∼3 nm. The other carbons synthesised at the sub-micrometric and nanometric length scales exhibit, in addition to the framework-confined porosity (∼3 nm), a textural porosity arising from the interparticle voids between the primary particles.