First-Principles Evaluation of the Morphology of WS2 Nanotubes for Application as Visible-Light-Driven Water-Splitting Photocatalysts

One-dimensional tungsten disulfide (WS2) single-walled nanotubes (NTs) with either achiral, i.e., armchair (n, n) and zigzag-type (n, 0), or chiral (2n, n) configuration with diameters dNT > 1.9 nm have been found to be suitable for photocatalytic applications, since their band gaps correspond to the frequency range of visible light between red and violet (1.5 eV 1.9 nm, the condition eVB < eO2/H2O < eH2/H2O < eCB is fulfilled. The values of eVB and eCB have been found to depend only on the diameter and not on the chirality ...