Mono-doped and co-doped nanostructured hematite for improved photoelectrochemical water splitting
| dc.contributor.author | Nyarige, Justine Sageka | |
| dc.contributor.author | Paradzah, Alexander Tapera | |
| dc.contributor.author | Kruger, T.P.J. (Tjaart) | |
| dc.contributor.author | Diale, M. (Mmantsae Moche) | |
| dc.contributor.email | mmantsae.diale@up.ac.za | en_US |
| dc.date.accessioned | 2023-09-27T04:44:04Z | |
| dc.date.available | 2023-09-27T04:44:04Z | |
| dc.date.issued | 2022-01-24 | |
| dc.description | DATA AVAILABILITY STATEMENT : The data used and or analysed during the current study are available from the corresponding author upon request. | en_US |
| dc.description.abstract | 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_US |
| dc.description.department | Physics | en_US |
| dc.description.librarian | am2023 | en_US |
| dc.description.sponsorship | Department of Physics, University of Pretoria, externally Funded UP Post-Doctoral Fellowship Programme, the African Laser Centre and Rental Pool Programme of the National Laser Centre and Department of Science and Innovation. | en_US |
| dc.description.uri | https://www.mdpi.com/journal/nanomaterials | en_US |
| dc.identifier.citation | Nyarige, 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. | en_US |
| dc.identifier.issn | 2079-4991 | |
| dc.identifier.other | 10.3390/nano12030366 | |
| dc.identifier.uri | http://hdl.handle.net/2263/92421 | |
| dc.language.iso | en | en_US |
| dc.publisher | MDPI | en_US |
| dc.rights | © 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. | en_US |
| dc.subject | Hematite nanoparticles | en_US |
| dc.subject | Doping | en_US |
| dc.subject | Chemical spray pyrolysis | en_US |
| dc.subject | Photocurrent | en_US |
| dc.subject | Water-splitting | en_US |
| dc.subject | Transient absorption spectroscopy | en_US |
| dc.subject | SDG-06: Clean water and sanitation | en_US |
| dc.title | Mono-doped and co-doped nanostructured hematite for improved photoelectrochemical water splitting | en_US |
| dc.type | Article | en_US |