  Transition metal dichalcogenides (TMDs) exhibit unique properties and
potential applications when reduced to one-dimensional (1D) nanoribbons (NRs),
owing to quantum confinement and high edge densities. However, effective growth
methods for self-aligned TMD NRs are still lacking. We demonstrate a versatile
approach for the lattice-guided growth of dense, aligned TMD NR arrays via
chemical vapor deposition (CVD) on anisotropic sapphire substrates, without the
need for tailored surface steps. This method enables the synthesis of NRs with
widths below 10 nm, with their longitudinal axis parallel to the zigzag
direction. The growth is influenced by both the substrate and CVD temperature,
indicating the role of anisotropic precursor diffusion and substrate
interaction. The 1D nature of the NRs was asserted by the observation of
Coulomb blockade at low temperature. Pronounced catalytic activity was observed
at the edges of the NRs, indicating their promise for efficient catalysis.
