Self-organized double-wall oxide nanotube layers on glass-forming Ti-Zr-Si(-Nb) alloys

Abstract In this work, we report for the first time on the use of melt spun glass-forming alloys - Ti 75 Zr 10 Si 15 (TZS) and Ti 60 Zr 10 Si 15 Nb 15 (TZSN) - as substrates for the growth of anodic oxide nanotube layers. Upon their anodization in ethylene glycol based electrolytes, highly ordered nanotube layers were achieved. In comparison to TiO 2 nanotube layers grown on Ti foils, under the same conditions for reference, smaller diameter nanotubes (~ 116 nm for TZS and ~ 90 nm for TZSN) and shorter nanotubes (~ 11.5 μm and ~ 6.5 μm for TZS and TZSN, respectively) were obtained for both amorphous alloys. Furthermore, TEM and STEM studies, coupled with EDX analysis, revealed a double-wall structure of the as-grown amorphous oxide nanotubes with Ti species being enriched in the inner wall, and Si species in the outer wall, whereby Zr and Nb species were homogeneously distributed.