In this study, zinc-doped (
-Fe
O
:Zn), silver-doped (
-Fe
O
:Ag) and zinc/silver co-doped hematite (
-Fe
O
:Zn/Ag) nanostructures were synthesized by spray pyrolysis. The synthesized nanostructures were used as photoanodes in the photoelectrochemical (PEC) cell for water-splitting. A significant improvement in photocurrent density of 0.470 mAcm
at 1.23 V vs. reversible hydrogen electrode (RHE) was recorded for
-Fe
O
:Zn/Ag. The
-Fe
O
:Ag,
-Fe
O
:Zn and pristine hematite samples produced photocurrent densities of 0.270, 0.160, and 0.033 mAcm
, respectively. Mott–Schottky analysis showed that
-Fe
O
:Zn/Ag had the highest free carrier density of 8.75 × 10
cm
, while pristine
-Fe
O
,
-Fe
O
:Zn,
-Fe
O
:Ag had carrier densities of 1.57 × 10
, 5.63 × 10
, and 6.91 × 10
cm
, respectively. Electrochemical impedance spectra revealed a low impedance for
-Fe
O
:Zn/Ag. X-ray diffraction confirmed the rhombohedral corundum structure of hematite. Scanning electron microscopy micrographs, on the other hand, showed uniformly distributed grains with an average size of <30 nm. The films were absorbing in the visible region with an absorption onset ranging from 652 to 590 nm, corresponding to a bandgap range of 1.9 to 2.1 eV. Global analysis of ultrafast transient absorption spectroscopy data revealed four decay lifetimes, with a reduction in the electron-hole recombination rate of the doped samples on a timescale of tens of picoseconds.
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