Self-ordered Mo-oxide Nanotube Arrays as Precursor for Aligned MoOx/MoS2   Core-Shell Nanotubular Structures with a High Density of Reactive Sites
  In the present work we demonstrate the self-organized formation of anodic Mo-oxide nanotube arrays grown on a Mo sheet under suitable electrochemical conditions in glycerol/NH4F electrolytes. The resulting amorphous tubes can be crystallized by annealing to MoO2 or MoO3. The tube walls then can be further sulfurized fully or partially to Mo-sulfide to form well-ordered arrays of vertically aligned MoOx/MoS2 nanotubes. Under optimized conditions, defined MoS2 sheets form on the oxide walls in a layer by layer low angle zig-zag arrangement that provide a high density of reactive stacking faults. These core-shell nanotube arrays, consisting of tubes with a conductive suboxide core and a functional high defect density MoS2 coating, are highly promising for applications such as electrocatalysis (hydrogen evolution) or ion insertion devices. 
Bowen Jin, Xuemei Zhou, Li Huang, Markus Licklederer, Min Yang, Patrik   Schmuki
cond-mat.mtrl-sci