Facile preparation of titanium dioxide nano-capsule arrays used as photo-anode for dye sensitized solar cells

To improve titanium dioxide (TiO2) nanotube arrays' performance on dye sensitized solar cells (DSSCs), TiO2 nano-capsule arrays (TNCP) have been designed and prepared by planting TiO2 nanoparticles into TiO2 nanotube (TNT) using a facile liquid phase deposition (LPD) route which does not require any special equipment and both improve the specific surface area and surface energy of TNT at low temperature. It has been found that TiO2 nanoparticles are homogeneously distributed along the wall of TNT and their crystal size is calculated to be 5-10 nm. The obtained TNCP's specific surface area and surface energy have been increased from 27.1 (for pure TNT) to 33.4 m(2)/g and from 67.7 (for pure TNT) to 76.4 mJ/m(2), respectively. When used as photo-anodes of DSSCs, TNCP shows higher energy conversion efficiency, which is 1.7 times that of pure TNT. Therefore, the present work provides one effective strategy to better TNT's performance on DSSCs, which can be assembled on metal substrate in large scale. (C) 2015 Elsevier B.V. All rights reserved.