Support Information:

S1. Top views of the TiO2 NTs fabricated at 10 V in BMIM-BF4 with water contents of a) 95 wt% and b) 2 wt%.

S2. Theta 2-theta XRD spectrum of the annealed IL-NTs-50V.

a b

Electronic Supplementary Material (ESI) for Journal of Materials ChemistryThis journal is © The Royal Society of Chemistry 2011

S3. Top views of TiO2 NTs fabricated in BMIM-BF4 with 2.6 wt% water under anodization potential of a) 50 V; b) 30 V; c) 20 V; d) 10 V.

c

ba

d

Electronic Supplementary Material (ESI) for Journal of Materials ChemistryThis journal is © The Royal Society of Chemistry 2011