Invited paperTiO2 nanotube arrays formation in fluoride/ethylene glycol electrolyte containing LiOH or KOH as photoanode for dye-sensitized solar cell

•TiO2 nanotubes (TNTs) formed by anodization in alkaline LiOH or KOH/fluoride/EG.•18 μm long TNTs were produced in KOH/fluoride/EG after 60 V for 60 min anodisation.•The as-anodised foils were crystalline due to oxygen generation and surface adsorbed OH−.•DSSC properties: Voc = 0.64 V, η = 3%, JC = 8.6 mA/cm2 and FF = 0.56.

The formation of TiO2 nanotube arrays by anodisation of Ti in fluoride/ethylene glycol (EG) electrolyte added to it lithium hydroxide (LiOH) or potassium hydroxide (KOH) at 60 V for 60 min was investigated. Highly ordered 15 μm long TiO2 nanotubes (TNTs) were produced in LiOH/fluoride/EG and 18 μm long TNTs were obtained in KOH/fluoride/EG. The as-anodized TNTs in these alkaline electrolytes were found to be crystalline and obviously annealing increases the crystallinity. Annealed TNTs were used as a photoanode in a backside illuminated dye-sensitized solar cell (DSSC). Photoconversion efficiency, η of 3% was achieved for sample with photoanode prepared in KOH/fluoride/EG higher than DSSC with TNTs photoanode fabricated in LiOH/fluoride/EG.

Graphical abstractDownload high-res image (132KB)Download full-size image