Graphite Intercalation Compounds Prepared in Hydrofluoric Acid

Abstract

AbstractThe graphite intercalation compounds CxC8F17SO3 · yF and CxN(SO2CF3)2 are readily prepared under ambient conditions in 48 % hydrofluoric acid, using the oxidant K2MnF6. The product compositions are evaluated by mass uptake, TGA, and elemental analysis. PXRD peak position and peak width analyses indicate that the stable product CxC8F17SO3 · yF is obtained after 50 h. (x ≅ 18, y ≅ 4) and is comprised of a solid solution of stage 2 and 3. This material can be obtained within 1 h. at 50 °C. The addition of up to 83 vol. % conc. HNO3 or 17 % fuming H2SO4 produces a stage 2 intercalation compound within hours. Stage 2 CxN(SO2CF3)2 (x = 37) is obtained within 15 minutes under ambient condition in HF. The anion orientations for these GICs are evaluated by structural refinement. Larger anions containing –SO2CnF2n+1 substitutents can also be intercalated, although the reaction rates are very slow.