Photoelectrochemical properties of Ti-doped hematite nanosheet arrays decorated with CdS nanoparticles

Abstract

Hematite (α-Fe₂O₃), with a relatively narrow bandgap (2.0–2.2 eV), is well-suited for potential application as a photoanode in photoelectrochemical (PEC) cells. Unfortunately, it suffers from severe bulk carrier recombination and low conductivity. This study provides a way to overcome these shortages by constructing a novel electrode system comprised of vertically aligned Ti-doped hematite nanosheet arrays decorated with cadmium sulfide nanoparticles (Ti-Fe₂O₃/CdS). Ti doping improves the conductivity of hematite and simultaneously extends the spectral responsive range. The incorporation of CdS nanoparticles further facilitates the charge separation and transfer process. Subsequently, the fabricated Ti-Fe₂O₃/CdS electrode achieves 6-fold enhancement of photocurrent density with respect to pristine Fe₂O₃ and excellent operation stability. Meanwhile, an obvious negative shift of photocurrent onset potential by 500 mV is observed.