Shaping powdered active carbons into monoliths without decreasing mesoporosity by using silica sol as binder

Powdered active carbon (PAC) was converted into monoliths without decreasing mesoporosity by using silica sol as a binder. The effects of sol dosage on physical properties of monoliths were investigated. The results indicated that using the sol could make the monoliths possess higher mesopore volume (Vmeso-BJH) and/or mesopore fraction (Vmeso-BJH/Vt) than the PAC, due to the mesoporous framework formed by the sol in the presence of PAC. Increasing the sol dosage could elevate the Vmeso-BJH or Vmeso-BJH/Vt of monoliths. When the dosage was 3.0 mL, we obtained a crack-free, regularly-shaped, and water-stable monolith with a Vmeso-BJH of 0.41 mL/g, Vmeso-BJH/Vt of 78.8%, BET specific area of 657 m2/g, and compressive strength of 1.7 Mpa. This research was favorable for preparing carbon-based mesoporous monoliths promising in removing large molecules from wastewater.