A simple combustion synthesis of ZnO/TiO₂ core-shell nanowires as a photoanode in dye-sensitized solar cells

Zinc oxide (ZnO) nanowires (NWs) have been used as a photoanode material for dye-sensitized solar cells (DSSCs). The ZnO NWs were grown easily on various substrates with a high electron mobility. But, it is vulnerable to acidic dye solution during the dye adsorption process. Here, we describe a new method to fabricate ZnO/tin oxide (TiO₂) core-shell nanowires that benefit from the chemical stability of TiO₂ in the acidic environment. TiO₂-covered ZnO NWs were prepared by simple droplet coating and subsequent combustion, preventing direct contact between the ZnO NWs and the dye solution. A DSSC with a ZnO/TiO₂ core-shell NWs photoanode had a power conversion efficiency (PCE) of 3.42%, enhanced by 96.8% relative to a DSSC with a photoanode of bare ZnO NWs.