In Situ Synthesis of Carbon Nanotube Hybrids with Alternate MoC and MoS₂ to Enhance the Electrochemical Activities of MoS₂

Molybdenum disulfides and carbides are effective catalysts for hydrogenation and hydridesulfurization, where MoS₂ nanostructures are also highly promising materials for lithium ion batteries. High surface-to-volume ratio and strong interactions with conducting networks are crucial factors for their activities. A new hybrid structure of multiwalled carbon nanotube (MWCNT) with alternate MoC nanoparticles and MoS₂ nanosheets (MoS₂ + MoC-MWCNT) has been synthesized by controlled carburization of core-shell MoS₂-MWCNT hybrid nanotubes and demonstrated by HRTEM, FFT, XRD, and Raman scattering. The MoS₂ nanosheets (∼10 nm) remain tightly connected to MWCNT surfaces with {001} planes in parallel to MWCNT walls and the highly crystallized α-MoC particles (∼10 nm) are adhered to MWCNTs at angles of 60-80° between {111} planes and MWCNT walls. The electrochemical performances of the hybrid structures have been demonstrated as anodes for lithium ion batteries to be significantly increased by breaking MoS₂ nanotubes into nanosheets (patches) on MWCNT surfaces, especially at high current rates. The specific capacities of MoS₂ + MoC-MWCNT sample with ∼23% MoS₂ have been demonstrated to be higher than those of MoS₂-MWCNTs containing ∼70% MoS₂.