Multifunctional flower-like WS2 hybrids with carbon nanotube veins and WS2 petals: Its sodium ion storage and hydrogen evolution properties

A hierarchical flower-like hybrid with tungsten disulfide (WS₂) nano-sheet petals and multi-walled carbon nanotube (MWCNT) veins is prepared via a facile solvothermal method. High concentration functional groups and defects on the acid-treated MWCNTs bundles initiated the growth of WS₂ nano-flowers with an average diameter of 500 nm, inducing strong interface interaction between WS₂ and MWCNTs. Furthermore, the MWCNTs are adopted as viens to improve the electron transportation and as interconnected 3D network to alleviate the structural change and restacking of WS₂ petals. Meanwhile, the WS₂ nano-flowers with abundant edge tungsten atoms are beneficial for sodium ion storage and hydrogen evolution reaction. As a result, the hybrid exhibits excellent electrochemical performances: a specific capacity of 250 mAh g⁻¹ at 0.5 A g⁻¹ after 45 cycles is retained as anode for sodium ion battery; an 80 mV dec⁻¹ Tafel slope and an overpotential of −0.25 V (vs. RHE) are delivered with excellent stability in acidic condition.