Heterojunction of nanostructured α-Fe2O3/CuO for enhancement of photoelectrochemical water splitting

In this research, nanostructured heterojunction of hematite (alpha-Fe2O3) and porous copper (II) oxide (CuO) composites represented as alpha-Fe2O3/CuO was prepared and used as photoanode for photoelectrochemical (PEC) water splitting. X-ray diffraction (XRD) and Raman spectroscopy studies confirmed the high purity of alpha-Fe2O3/CuO heterostructures produced. Enhanced photocurrent density of 0.53 mA/cm(2) at 1.0 V versus reversible hydrogen electrode (vs. RHE) was achieved for alpha-Fe2O3/CuO photoanodes, representing a 19-fold increase compared to the value recorded for alpha-Fe2O3. The formation of a heterojunction coupled with the porous surface morphology of alpha-Fe2O3/CuO heterostructure facilitated charge separation of photogenerated electron-hole pairs, enhancing PEC water splitting. The reduced bandgap recorded for alpha-Fe2O3/CuO resulted in increased absorption of photons in the visible spectrum by the heterostructure, which also influenced the improvement of the photocurrent density. Furthermore, increase in charge carrier density and the reduction of charge transfer resistance at the liquid/solid interface achieved for alpha-Fe2O3/CuO were additional evidence associated with the improvement in the recorded current density. This research presents the formation of alpha-Fe2O3/CuO heterojunction structure with porous surface as a viable route to achieving notable improvement in the photo response of alpha-Fe2O3 photoanodes for PEC water splitting. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This research focused on preparing nanostructured heterojunction of alpha-Fe2O3 and porous CuO composites as photoanodes for PEC water splitting. The formations of heterojunction and porous surface morphology facilitated charge separation and enhanced PEC efficiency. The reduced bandgap and increased photon absorption in the visible spectrum were key factors in improving photocurrent density.