Electrodeposition of Ni oxide on TiO2 nanotube arrays for enhancing visible light photoelectrochemical water splitting

The photoelectrochemical water splitting into hydrogen and oxygen using sun light is a potentially clean and renewable source of hydrogen fuel. TiO2 nanotubes (NTs) grown by anodization in a fluoride based electrolyte were loaded with Ni oxide nanoparticles by a pulse electrodeposition method. The fabricated NiOx/TiO2NTs electrodes were characterized by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS) and X-ray photoemission spectroscopy (XPS). The photoelectrochemical property of fabricated NiOx/TiO2NTs electrodes was characterized by using a compartment cell. It was found that the Ni oxide nanoparticles loaded enhanced the visible spectrum absorption of the TiO2 nanotube arrays, as well as their solar-spectrum induced photocurrents, while a reverse result was obtained under UV-light illumination.

► TiO2 nanotubes grown by anodization in a fluoride based electrolyte were loaded with Ni oxide nanoparticles by a pulse electrodeposition method. ► The nanoparticles inside of the tube wall have a comparably uniform size distribution with an average size of approximately 80 nm. ► The Ni oxide nanoparticles loaded enhanced the visible spectrum absorption of the TiO2 nanotube arrays, as well as their solar-spectrum induced photocurrents.