XAFS STUDY OF MOS2 INTERCALATION COMPOUNDS

MoS2 intercalated with Mn, Co, Ni, and Ru species, prepared from singl e layer MoS2 dispersions in water, were studied by x-ray absorption sp ectroscopy. M K-edge EXAFS results (M = Mn, Co, Ni) are consistent wit h an alternating MoS2-M(OH)(2) layered structure. For the Mn and Co in tercalates the MoS2 layers were found to be very similar to that of th e parent crystalline MoS2 with trigonal prismatic coordination of the Mo atoms. For the Ni and Ru intercalates, Mo K edge EXAFS revealed str uctural rearrangement of MoS2 layers similar to that observed for MoS2 single layers, with octahedral coordination of Mo, S K edge XANES spe ctra reveal that the rearrangement is coupled with a change in the ele ctronic structure of the S atoms in the matrix. These changes can be a ssociated with charge transfer between 'host' and 'guest' layers. In a ddition, SO42- and Mo6+ were detected in some of the intercalated mate rials, presumably due to exposure to air, suggesting that transition m etal intercalation may increase the susceptibility of the MoS2 layers to oxidation.