Morphologically Tunable Fabrication of Hematite Nanostructures for Enhanced Photoelectrochemical Performance

Abstract

Herein, a photoelectrochemical investigation of photoanodes based on hematite nanorods and nanospheres fabricated via hydrothermal technique is reported. The fabricated nanostructures have been thoroughly analyzed and characterized using field emission scanning electron microscopy (FESEM), X-ray Diffractometer (XRD), UV-Visible spectroscopy, Photoluminescence spectroscopy (PL), and X-ray photoelectron spectroscopy (XPS). The presence of oxygen vacancies and morphological characteristics of Hematite photoanodes were shown to be directly related to their photoelectrochemical performances. The nanorod-based photoanode yields an excellent photocurrent density of 1.63 mAcm2 which was about 4 times greater than the nanosphere-based photoanode. Further hematite nanorods showed efficient charge transfer kinetics, increased donor density and, excellent photo stability. The enhancement in photoelectrochemical properties of nanorods can be attributed to the oxygen vacancies generated in hematite nanorods which provide excellent electrical conductivity and better charge transfer kinetics. The results demonstrate that oxygen vacancy-rich nanorods can serve as ideal photoelectrode for enhancing the electrochemical properties of hematite nanostructures.