Dopamine-Assisted Synthesis of MoS2 Nanosheets on Carbon Nanotube for Improved Lithium and Sodium Storage Properties

Hybrid materials with delicate composition and morphology usually promote advanced functions. We report a simple synthesis approach to coaxially grow MoS2 nanosheets on carbon nanotubes (CNTs), which were precoated with polydopamine (PDA), with the ability to readily control phase and morphology. It is found that the thin PDA layer on CNTs surface with abundant catechol base and chinone base can effectively attract both Mo4+ and S2– for subsequently in situ forming MoS2 shell and sheet-like morphology, and therefore, it is essential for the successful deposition of MoS2. The as-prepared MoS2 nanosheets/CNTs (MoS2@CNT) composite with a unique hierarchical hybrid nanostructure with large active surface and enhanced structural robustness has greatly promoted the charge-transfer process and enhanced the electrochemical properties when used as the electrode materials for lithium-ion batteries and sodium-ion batteries. As the anode materials for LIBs, the MoS2@CNTs electrode exhibited extremely stable cycling performance with an excellent capacity of 747.3 mA h g–1 over 200 cycles at 200 mA g–1. As for SIBs, MoS2@CNT showed a high capacity of 512.4 mA h g–1 at 200 mA g–1 after 100 cycles. These results demonstrated the importance of the synthesis and the application potentials of MoS2@CNTs electrodes with both long cycling performance and good rate capability in future energy-storage devices.