Preparation of nanoporous MgO-Coated TiO2 nanoparticles and their application to the electrode of dye-sensitized solar cells

Sol-gel-derived Mg(OH)(2) gel was coated onto TiO2 nanoparticles, and the subsequent thermal topotactic decomposition of the gel formed a highly nanoporous MgO crystalline coating. The specific surface area of the electrode that was prepared from the core - shell-structured TiO2 nanoparticles significantly increased compared with that of the uncoated TiO2 electrode. The increase in the specific surface area of the MgO-coated TiO2 electrode was attributed to the highly nanoporous MgO coating layer that resulted from the topotactic reaction. Dye adsorption behavior and solar cell performance were significantly enhanced by employing the MgO-coated TiO2 electrode. Optimized coating of a MgO, layer on TiO2 nanoparticles enhanced the energy conversion efficiency as much as 45% compared to that of the uncoated TiO2 electrode. This indicates that controlling the extrinsic parameters such as the specific surface area is very important to improve the energy conversion efficiency of TiO2-based solar cells.