Preparation of magnetic sorbent based on exfoliated graphite with different content of cobalt ferrite

Abstract

Exfoliated graphite (EG) containing CoFe2O4 was obtained by impregnation of expandable graphite in mixed solution of FeCl3 and Co(NO3)2 and subsequent thermal treatment of expandable graphite at 1000 oC in air atmosphere. Expandable graphite based on graphite bisulfate of I and II stages, graphite nitrate of II stage and electrochemical graphite nitrate with different degrees of the graphite matrix oxidation was used. The different preparation conditions lead to different CoFe2O4 content in EG, which is varied from 7 to 45 wt.%. Obtained EG is characterized by high sorption capacity toward oil (25 g/g) and low water absorption (2 g/g).