Efficient electrochromic smart windows of one dimensional pure brookite TiO2 nanoneedles
Abstract We report on the electrochromic behaviors of pure 1D brookite TiO2 nanoneedles grown on a conducting indium tin oxide thin film coated a glass substrate. The pure 1D brookite TiO2 nanoneedles of ~650 nm long and ~30 nm wide were synthesized via hot filament metal oxide vapor deposition. X ray diffractometry analysis revealed the pure 1D brookite TiO2 nanoneedles to be in orthorhombic crystalline form within space group Pbca. The excellent electrochromic characteristics, including the stable and reversible coloration bleaching cycles, and fair diffusion coefficient ~1.56x10 11 cm2/s) high reversibility ~99% great coloration efficiency (226 cm2/C) high optical transmittance difference ~67% large optical density (0.85) and fast coloration and bleaching times (13.10 and 5.14 s) at a wavelength of 600 nm, make the pure 1D brookite TiO2 nanoneedles very good materials for use in smart windows.