Facile Preparation, Structural Control and Spheroidization of Mesoporous Carbons Using Hydrolyzed Water Glass as a Template

Mesoporous carbons(MC) with controlled pore structure were synthesized using hydrolyzed water glass(sodium silicate) as hard template precursor. The mixture of carbon precursor(resorcinol-formaldehyde) sol and silica sol followed by Sol-Gel process generated a polymer/silica dual hydrogels. After ambient drying, carbonization and HF etching, mesoporous carbons with developed mesoporous structure were obtained. The hydrolysis conditions of water glass including hydrolysis temperature and hydrolysis time, and the weight ratio of RF polymer to silica were studied respectively to investigate their effects on the mesoporous structure. The microstructures of the mesoporous carbons were characterized by N2 adsorption, SEM and TEM observations. It was found that as-prepared mesoporous carbons displayed disordered mesoporous channels which replicated from the initial colloidal silica networks. The average mesopore size could be precisely adjusted in the range from 6 nm to 12 nm by tuning the hydrolysis time and hydrolysis temperature, while the total porosity could be controlled by changing the weight ratio of polymer precursor to silica. Furthermore, with the assistant of suspension polymerization and spray drying technologies, spherical mesoporous carbons with millimetre and micrometer-sized particles were drying technologies, spherical mesoporous carbons with millimetre and micrometer-sized particles were produced, respectively. The present work provides a low-cost approach for deliberately controlling the mesoporous structure and spherical morphology to mesoporous carbons that can be extended to many different applications.