• Protic ionic liquids were used to fabricate TiO 2 nanotubes as photoelectrocatalysts • Triethanolamine (TEA) was the most efficient PIL • Almost 100% of N 2 O was eliminated after 3h using the sample with 0.25 % v/v TEA • Anodes in Li-ion battery showed specific capacities near theoretical value In this work, novel titanium dioxide nanotubes have been synthesized by electrochemical anodization using different protic ionic liquids (PILs) to study the effect on two different environmental applications. Namely, the photoelectro-reduction of nitrous oxide and the use as anode in Li-ion batteries. Morphological, structural, physicochemical and (photo)electrochemical characterization of the samples was carried out to reveal the best nanostructure for each application. Among all the ionic liquids tested, triethanolamine (TEA) resulted to be the most efficient PIL, due to the longer and wider resulting nanotubes (6.615 µm and 54 nm, respectively for IL-0.25 sample). Different IL concentrations and hydrodynamic conditions were tested during anodization. The best electrochemical response in both applications was obtained by the sample synthesized using a TEA concentration of 0.25% v/v and 500 rpm. The results revealed the good suitability of this nanostructure, as 97% of N 2 O was eliminated after only 2h of experiment and 100% was reached after 3h. When tested as an anode in Li-ion batteries, specific capacity for slow charging velocities reached almost theoretical values and, for faster velocities, it demonstrated a capacity ca. 50% higher than an analogous sample synthesized in static conditions and without ionic liquid.
Sánchez et al. (Fri,) studied this question.