Vertically aligned ultrathin MoS₂ nanosheets grown on graphene-wrapped hollow carbon microtubes derived from loofah sponge as advanced anodes for highly reversible lithium storage

Using low cost, environment-friendly, and sustainable biomass is a unique approach to the preparation carbon-based composites for lithium ion batteries. In our research, hollow, derived microtubes (HMD) were fabricated from graphene/loofah sponge. Each microtube was wrapped with graphene, resulting in conductivity improvement, and facilitated easily controlled growth of ultra-thin MoS₂ nanosheets. The method employed a simple process of soaking the HMD in graphene oxide (GO) dispersion liquid, and subsequent carbonization and activation of the HMD/rGO. When ultrathin MoS₂ nanosheets were vertically and uniformly grown on the surface of the HMD/rGO, via the hydrothermal method, the HMD/rGO/MoS₂ composite was obtained, and exhibited reversible lithium storage capacity of 838.2 mAh g⁻¹ at a current density of 0.2 A g⁻¹ after 200 cycles. This excellent electrochemical performance could be due to the high conductivity of HMD/rGO, a synergistic effect between HMD/rGO and MoS₂ nanosheets, a reasonable structural design, and the high theoretical specific capacity of MoS₂. Such a structure not only provides a novel, high-quality carbon template/matrix from cheap loofah sponge, but also provides a new way to design sustainable electrodes for electrochemical energy storage, and makes economical, multifunctional, carbon-based hybrids available for other applications.