Titanium dioxide nanopowder

Absolute ethanol (> 99%), Triton X-100 (laboratory grade), di-tetrabutylammonium cis-bis (isothiocyanato) bis (2,2’-bipyridyl-4,4’-dicarboxylato) ruthenium (II) dye (N-719, 95%), acetonitrile (gradient grade), tert-butyl alcohol (≥ 99.7%) and titanium dioxide nanopowder (21 nm primary particle size, ≥ 99.5% trace metals basis) were purchased from Sigma–Aldrich, Oslo, Norway. Acetylacetone (≥ 99.5%) was purchased from Fluka Analytical, Munich, Germany. All the materials were used without further purification unless otherwise stated.

Titanium dioxide nanopowder, with a particle size until 25 nm (Sigma Aldrich Chemical Company St. Louis, MO, USA, Titanium IV Oxide, Anatase nanopowder), was used to conduct the experiments. The titanium dioxide powder was spread on a weighing paper and gently picked up by the sticky carbon surface above the aluminum stubs. An S4700 II cFEG SEM (Hitachi High Technologies-America, Schaumburg, IL, US) with a silicon drift EDX detector (Oxford Instruments, X-MaxN, Abingdon, UK) was used to measure the surface morphology, elemental composition, and distribution of elements. All the SEM data reported were obtained at an acceleration voltage of 10 kV, and the images were collected with a Secondary Electron detector. The elemental mapping and energy spectrums were acquired with Aztec tools (Oxford Instruments, UK). The elemental analysis through the energy dispersive spectrum indicated the presence of Ti, O, C, and S elements (61, 36.1, 2.6, and 0.3 wt%, respectively) (Figure 1).