The influence of the acid source on the structural and anti-oxidation properties of ordered mesoporous carbons

Abstract

The synthesis of ordered mesoporous carbons (OMCs) was carried out under acidic aqueous conditions, by cooperative self-assembly of phenol–formaldehyde resol and surfactant F127. The influence of the acid source on the structural and anti-oxidation properties of the OMCs was investigated. The acids (HCl, HNO₃, H₃PO₄ and H₂SO₄) used in the synthesis are sufficient to induce the self-assembly of resol and F127 to form the mesophase, while the final products carbonized at 600 °C show different structural properties. This was mainly due to the different decomposition behaviors of the surfactant during the carbonization process, which depends on the nature of the anions from the acids. After oxidization in acidic (NH₄)₂S₂O₈ solution, the H₃PO₄ catalyzed sample undergoes a minimum reduction in surface area and pore volume, and exhibits a larger adsorptive capacity for Co²⁺, compared with those using HCl and HNO₃ as catalyst. This was related to the incorporation of the phosphorus atoms in the sample with H₃PO₄ as catalyst, which is in favour of increasing the carbonization degree of the sample, and they can also act as adsorptive sites for Co²⁺.