Surface Morphology and Growth of Anodic Titania Nanotubes Films: Photoelectrochemical Water Splitting Studies

Abstract EN

Design and development of one-dimensional nanoarchitecture titania (TiO) assemblies have gained significant scientific interest, which havebecome the most studied material as they exhibit promising functional properties.

In the present study, anodic TiO2 films with different surface morphologies can be synthesized in an organic electrolyte of ethylene glycol (EG) by controlling an optimum content of ammonium fluoride (NH4F) using electrochemical anodization technique.

Based on the results obtained, well-aligned and bundle-free TiO2 nanotube arrays with diameter of 100 nm and length of 8 µm were successfully synthesized in EG electrolyte containing ≈5 wt% of NH4F for 1 h at 60 V.

However, formation of nanoporous structure and compact oxide layer would be favored if the content of NH4F was less than 5 wt%.

In the photoelectrochemical (PEC) water splitting studies, well-aligned TiO2 nanotubular structure exhibited higher photocurrent density of ≈1 mA/cm2 with photoconversion efficiency of ≈2% as compared to the nanoporous and compact oxide layer due to the higher active surface area for the photon absorption to generate more photo-induced electrons during photoexcitation stage.