Solvothermal polycondensation of novolacs phenolic-resin to nanopowders and their derived activated nanocarbons as efficient adsorbents for water cleaning

摘要

Novolacs phenolic-resin (PF) was easily polycondensed into polymeric powders with sizes and morphologies ranging from microspheres to nanoparticles by a simple solvothermal process without adding any crosslinking agent. Activating the highly divided PF powders by CO2 resulted in nanosize activated carbons with high specific surface area (2092 m(2) g(-1)) and large pore volume (1.33 cm(3) g(-1)) while preserving a high carbon yield of about 38 wt%. As for adsorption tests, the micropore-dominated activated nanocarbons exhibited fast and high adsorption capabilities towards both Cr(VI) ions and bulky rhodamine B molecules due to their much improved external surface area and the greatly shortened intra-particle diffusion distance. The equilibrium adsorption amounts of Cr(VI) and RB on the activated nanocarbons as estimated by the Langmuir model were 200 and 990 mg g(-1), achieved within an adsorption time of 30 and 360 min, respectively.