Synthesis of visible-light absorbing CoFe₂O₄ sensitized TiO₂ nanotube arrays electrode with enhanced photoelectrochemical performance

Graphical abstract: - Highlights: • TiO₂ nanotube sensitized with CoFe₂O₄ nanocrystals was synthesized by a facile hydrothermal method. • CoFe₂O₄ nanocrystals were loaded to the outer and inner surface of TiO₂ nanotube. • The CoFe₂O₄ sensitized TiO₂ nanotube electrode has a strong photoresponse to the light. - Abstract: TiO₂ nanotube arrays sensitized with CoFe₂O₄ nanocrystals were successfully synthesized via a facile hydrothermal method. The as-prepared sample was studied by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX) to characterize its phase structure, morphology and chemical composition. Enhanced absorption in both UV and visible-light regions was observed for the CoFe₂O₄ sensitized TiO₂ nanotube arrays. The photocurrent density of CoFe₂O₄ sensitized TiO₂ nanotube arrays electrode was 30 times as great as that of bare TiO₂ nanotube arrays electrode