Nyarige, Justine SagekaParadzah, Alexander TaperaKruger, T.P.J. (Tjaart)Diale, M. (Mmantsae Moche)2023-09-272023-09-272022-01-24Nyarige, J.S.; Paradzah, A.T.; Krüger, T.P.J.; Diale, M. Mono-Doped and Co-Doped Nanostructured Hematite for Improved Photoelectrochemical Water Splitting. Nanomaterials 2022, 12, 366. https://DOI.org/10.3390/nano12030366.2079-499110.3390/nano12030366http://hdl.handle.net/2263/92421DATA AVAILABILITY STATEMENT : The data used and or analysed during the current study are available from the corresponding author upon request.In this study, zinc-doped (a-Fe2O3:Zn), silver-doped (a-Fe2O3:Ag) and zinc/silver codoped hematite (a-Fe2O3:Zn/Ag) nanostructures were synthesized by spray pyrolysis. The synthesized nanostructures were used as photoanodes in the photoelectrochemical (PEC) cell for watersplitting. A significant improvement in photocurrent density of 0.470 mAcm2 at 1.23 V vs. reversible hydrogen electrode (RHE) was recorded for a-Fe2O3:Zn/Ag. The a-Fe2O3:Ag, a-Fe2O3:Zn and pristine hematite samples produced photocurrent densities of 0.270, 0.160, and 0.033 mAcm2, respectively. Mott–Schottky analysis showed that a-Fe2O3:Zn/Ag had the highest free carrier density of 8.75 1020 cm3, while pristine a-Fe2O3, a-Fe2O3:Zn, a-Fe2O3:Ag had carrier densities of 1.57 1019, 5.63 1020, and 6.91 1020 cm3, respectively. Electrochemical impedance spectra revealed a low impedance for a-Fe2O3: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.en© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.Hematite nanoparticlesDopingChemical spray pyrolysisPhotocurrentWater-splittingTransient absorption spectroscopySDG-06: Clean water and sanitationArticle