Effect of in-situ Fe doping on the visible light photoelectrochemical activity of TiO2 nanorods

Abstract

Considering its superior photocatalytic activity and excellent chemical stability, titanium dioxide (TiO₂) is an excellent candidate for photoelectrochemical (PEC) hydrogen production. Besides, many challenges exist ahead of improving the photoresponse of TiO₂ to visible light while maintaining high photocatalytic activity. Herein, the authors report recent efforts to improve the visible light PEC activity of TiO₂ nanorods by in-situ doping with various iron (Fe) concentrations using a hydrothermal method. The influences of Fe doping concentrations on the morphological and structural properties of TiO₂ nanorods were investigated by using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. Furthermore, this work demonstrates that Fe doping could improve the PEC activity of TiO₂ nanorods under visible light irradiation. The authors achieve a remarkable enhancement in the photocurrent density, as high as 2.9 mA/cm² at an applied voltage of 0.5 V, for the sample synthesised with an Fe doping concentration of 10 mM. These results reveal that Fe-doped TiO₂ nanorods can serve as ideal materials for PEC applications.