Enhanced platinum and palladium recovery from aqueous solutions : a comparative study of acylthiourea and amine-modified silica gel adsorbents
dc.contributor.author | Mphahlele, Malehlogonolo R.R. | |
dc.contributor.author | Mosai, Alseno Kagiso | |
dc.contributor.author | Tutu, Hlanganani | |
dc.contributor.author | Kotze, Izak A. | |
dc.date.accessioned | 2025-07-03T12:09:28Z | |
dc.date.available | 2025-07-03T12:09:28Z | |
dc.date.issued | 2025 | |
dc.description | DATA AVAILABILITY : The data supporting the findings of this study are available within the article and the ESI. | |
dc.description.abstract | The recovery of precious metals from secondary sources is becoming increasingly important due to their natural scarcity and rising industrial demand. This study introduces a novel adsorbent, N-triethoxysilylpropyl-N′-benzoylthiourea-modified silica gel (TESP-BT-SG), developed for the selective recovery of platinum (Pt) and palladium (Pd) from aqueous solutions that simulate refinery wastewater. The extraction capabilities of TESP-BT-SG were compared with those of an amine-bearing adsorbent, (3-aminopropyl)triethoxy-silane-modified silica gel (APTES-SG), previously recognized for Pt and Pd recovery. Under optimal conditions, TESP-BT-SG achieved extraction efficiencies of 97% for Pt and 99% for Pd. Both adsorbents demonstrated rapid adsorption kinetics for Pd relative to Pt, reaching equilibrium within 3 hours for Pd and within 6 hours (TESP-BT-SG) and 24 hours (APTES-SG) for Pt. In solutions with elevated competing ion concentrations (5–100 mg L−1), both adsorbents retained high selectivity (>97%) for Pt and Pd. Adsorption isotherms and kinetic models were applied to elucidate the adsorption mechanisms, with the Langmuir isotherm and pseudo-second-order models providing the best fits, indicating monolayer coverage and chemisorption, respectively. Notably, the APTES-SG sorbent demonstrated enhanced performance with an increased loading capacity of 2.45 mmol g−1 compared to the previously reported 1.15 mmol g−1, achieved through our improved synthesis method. This modified APTES-SG showed significantly higher affinity for Pd (98%), Pt (97%), and iridium (Ir) (89%) compared to previous values of 8%, 33%, and 42%, respectively. The exceptional efficiency and selectivity of these silica-anchored adsorbents underscore their potential as cost-effective solutions for industries seeking to recover precious metals. | |
dc.description.department | Chemistry | |
dc.description.librarian | hj2025 | |
dc.description.sdg | SDG-12: Responsible consumption and production | |
dc.description.sdg | SDG-06: Clean water and sanitation | |
dc.description.sponsorship | The National Research Foundation (NRF). | |
dc.description.uri | https://pubs.rsc.org/en/journals/journal/ra | |
dc.identifier.citation | Mphahlele, M.R.R., Mosai, A.K., Tutu, H. & Kotze, I.A. Enhanced platinum and palladium recovery from aqueous solutions: a comparative study of acylthiourea and amine-modified silica gel adsorbents', RSC Advances, vol. 15, no. 6, pp. 4607-4618, doi : 10.1039/d4ra07935c. | |
dc.identifier.issn | 2046-2069 (online) | |
dc.identifier.other | 10.1039/d4ra07935c | |
dc.identifier.uri | http://hdl.handle.net/2263/103162 | |
dc.language.iso | en | |
dc.publisher | Royal Society of Chemistry | |
dc.rights | © 2025 The Author(s). Published by the Royal Society of Chemistry. This article is licensed under aCreative Commons Attribution-NonCommercial 3.0 Unported Licence. | |
dc.subject | N-triethoxysilylpropyl-N′-benzoylthiourea-modified silica gel (TESP-BT-SG) | |
dc.subject | Platinum | |
dc.subject | Palladium | |
dc.subject | Aqueous solutions | |
dc.subject | Wastewater | |
dc.subject | 3-aminopropyl)triethoxy-silane-modified silica gel (APTES-SG) | |
dc.title | Enhanced platinum and palladium recovery from aqueous solutions : a comparative study of acylthiourea and amine-modified silica gel adsorbents | |
dc.type | Article |
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