Anodic synthesis of highly ordered TiO₂ nanotube arrays- role of electrolyte composition on the structural, morphological, optical, and photo-electrochemical properties

The fluoride species present in two different anodizing electrolytes were used to produce TiO₂ nanotube arrays (TiOv NTAs) by simultaneous anodic reaction and chemical dissolution. In this investigation, two different electrolytes were used for the preparation; [Eth-TiO₂ NAs: 95 ml ethylene glycol+0.5% NH4F+5 ml DI water] and [Gly-TiO₂ NAs: 75 ml glycerine+0.5% NH4F+25 ml DI water]. The effects of the prepared electrolytes used in the synthesis of TiO₂ nanotube arrays on structural element composition, morphology, and optical properties are the focus of this study and are characterized by X-ray diffraction (XRD), scanning electron microscopy field emission (FE-SEM), energy-dispersive X-ray spectroscopy (EDX) and UV-vis diffusion reflection spectroscopy (DRS), respectively. The photoelectrochemical properties of TiO₂ NTAs prepared in different electrolytes were investigated. The photoelectrochemical performance of TiO₂ NTAs in Na2SO3 (0.1 M) and Na2S (0.1) was examined under the light of 100 mW/cm2 from a xenon lamp. Comparing the photoelectrochemical (PEC) results of both electrolytes, we find that Eth-TiO₂ NTAs contribute a wide surface area resulting in an enhanced PEC response. TiO₂ NTs, which were prepared with Eth-TiO₂ NTAs, exhibited the highest photocurrent density, 0.326 mA cm–2, and photoconversion efficiency (0.22%).