Physical and photoelectrochemical properties of Zr-doped hematite nanorod arrays

This work examines the effect of Zr4+ ions on the physical and photoelectrochemical (PEC) properties of hematite (alpha-Fe2O3) nanorod arrays grown in an aqueous solution containing zirconyl nitrate (ZrO(NO3)(2)) as a dopant precursor. The concentration of ZrO(NO3)(2) in the precursor solution influenced both the film thickness and the Zr4+ concentration in the resulting films. Zr doping was found to enhance the photocurrent for water splitting; the highest photocurrent at 1.0 V vs. Ag/AgCl (0.33 mA cm(-2)) for the Zr-doped alpha-Fe2O3 film was approximately 7.2 times higher than that for the undoped film (0.045 mA cm(-2)). Additionally, the incident photon to current efficiency (IPCE) at 360 nm and 1.23 V vs. the reversible hydrogen electrode (RHE) increased from 3.8% to 13.6%. Ultrafast transient absorption spectroscopy suggests that Zr doping may influence PEC performance by reducing the rate of electron-hole recombination.