TiO 2-photocatalytic reduction of pentavalent and trivalent arsenic: Production of elemental arsenic and arsine
Heterogeneous photocatalytic reduction of As(V) and As(III) at different concentrations over TiO 2 under UV light in deoxygenated aqueous suspensions is described. For the first time, As(0) was unambiguously identified together with arsine (AsH3) as reaction products. As(V) reduction requires the pr...
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todo:paper_0013936X_v46_n4_p2299_Levy2023-10-03T14:11:41Z TiO 2-photocatalytic reduction of pentavalent and trivalent arsenic: Production of elemental arsenic and arsine Levy, I.K. Mizrahi, M. Ruano, G. Zampieri, G. Requejo, F.G. Litter, M.I. Aqueous suspensions Conduction band electrons Direct Reduction Electron donors Hydroxyl radicals Methanol Oxidation Photocatalytic process Photocatalytic reduction TiO Arsenic Methanol Suspensions (fluids) Titanium dioxide Water treatment arsenic arsine hydroxyl radical methanol titanium dioxide aqueous solution arsenic catalysis concentration (composition) electron hydroxyl radical methanol oxidation photodegradation pollutant removal reduction titanium water treatment aqueous solution article concentration (parameters) electron photocatalysis reduction solid ultraviolet radiation X ray absorption spectroscopy Arsenic Arsenicals Catalysis Oxidation-Reduction Photochemical Processes Titanium Ultraviolet Rays Water Pollutants, Chemical Heterogeneous photocatalytic reduction of As(V) and As(III) at different concentrations over TiO 2 under UV light in deoxygenated aqueous suspensions is described. For the first time, As(0) was unambiguously identified together with arsine (AsH3) as reaction products. As(V) reduction requires the presence of an electron donor (methanol in the present case) and takes place through the hydroxymethyl radical formed from methanol oxidation by holes or hydroxyl radicals. On the contrary, As(III) reduction takes place through direct reduction by the TiO 2-conduction band electrons. Detailed mechanisms for the photocatalytic processes are proposed. Although reduction to solid As(0) is convenient for purposes of As removal from water as a deposit on TiO 2, attention must be paid to formation of AsH 3, one of the most toxic forms of As, and strategies for AsH3 treatment should be considered. © 2012 American Chemical Society. Fil:Levy, I.K. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Litter, M.I. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_0013936X_v46_n4_p2299_Levy |
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Universidad de Buenos Aires |
| institution_str |
I-28 |
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R-134 |
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Aqueous suspensions Conduction band electrons Direct Reduction Electron donors Hydroxyl radicals Methanol Oxidation Photocatalytic process Photocatalytic reduction TiO Arsenic Methanol Suspensions (fluids) Titanium dioxide Water treatment arsenic arsine hydroxyl radical methanol titanium dioxide aqueous solution arsenic catalysis concentration (composition) electron hydroxyl radical methanol oxidation photodegradation pollutant removal reduction titanium water treatment aqueous solution article concentration (parameters) electron photocatalysis reduction solid ultraviolet radiation X ray absorption spectroscopy Arsenic Arsenicals Catalysis Oxidation-Reduction Photochemical Processes Titanium Ultraviolet Rays Water Pollutants, Chemical |
| spellingShingle |
Aqueous suspensions Conduction band electrons Direct Reduction Electron donors Hydroxyl radicals Methanol Oxidation Photocatalytic process Photocatalytic reduction TiO Arsenic Methanol Suspensions (fluids) Titanium dioxide Water treatment arsenic arsine hydroxyl radical methanol titanium dioxide aqueous solution arsenic catalysis concentration (composition) electron hydroxyl radical methanol oxidation photodegradation pollutant removal reduction titanium water treatment aqueous solution article concentration (parameters) electron photocatalysis reduction solid ultraviolet radiation X ray absorption spectroscopy Arsenic Arsenicals Catalysis Oxidation-Reduction Photochemical Processes Titanium Ultraviolet Rays Water Pollutants, Chemical Levy, I.K. Mizrahi, M. Ruano, G. Zampieri, G. Requejo, F.G. Litter, M.I. TiO 2-photocatalytic reduction of pentavalent and trivalent arsenic: Production of elemental arsenic and arsine |
| topic_facet |
Aqueous suspensions Conduction band electrons Direct Reduction Electron donors Hydroxyl radicals Methanol Oxidation Photocatalytic process Photocatalytic reduction TiO Arsenic Methanol Suspensions (fluids) Titanium dioxide Water treatment arsenic arsine hydroxyl radical methanol titanium dioxide aqueous solution arsenic catalysis concentration (composition) electron hydroxyl radical methanol oxidation photodegradation pollutant removal reduction titanium water treatment aqueous solution article concentration (parameters) electron photocatalysis reduction solid ultraviolet radiation X ray absorption spectroscopy Arsenic Arsenicals Catalysis Oxidation-Reduction Photochemical Processes Titanium Ultraviolet Rays Water Pollutants, Chemical |
| description |
Heterogeneous photocatalytic reduction of As(V) and As(III) at different concentrations over TiO 2 under UV light in deoxygenated aqueous suspensions is described. For the first time, As(0) was unambiguously identified together with arsine (AsH3) as reaction products. As(V) reduction requires the presence of an electron donor (methanol in the present case) and takes place through the hydroxymethyl radical formed from methanol oxidation by holes or hydroxyl radicals. On the contrary, As(III) reduction takes place through direct reduction by the TiO 2-conduction band electrons. Detailed mechanisms for the photocatalytic processes are proposed. Although reduction to solid As(0) is convenient for purposes of As removal from water as a deposit on TiO 2, attention must be paid to formation of AsH 3, one of the most toxic forms of As, and strategies for AsH3 treatment should be considered. © 2012 American Chemical Society. |
| format |
JOUR |
| author |
Levy, I.K. Mizrahi, M. Ruano, G. Zampieri, G. Requejo, F.G. Litter, M.I. |
| author_facet |
Levy, I.K. Mizrahi, M. Ruano, G. Zampieri, G. Requejo, F.G. Litter, M.I. |
| author_sort |
Levy, I.K. |
| title |
TiO 2-photocatalytic reduction of pentavalent and trivalent arsenic: Production of elemental arsenic and arsine |
| title_short |
TiO 2-photocatalytic reduction of pentavalent and trivalent arsenic: Production of elemental arsenic and arsine |
| title_full |
TiO 2-photocatalytic reduction of pentavalent and trivalent arsenic: Production of elemental arsenic and arsine |
| title_fullStr |
TiO 2-photocatalytic reduction of pentavalent and trivalent arsenic: Production of elemental arsenic and arsine |
| title_full_unstemmed |
TiO 2-photocatalytic reduction of pentavalent and trivalent arsenic: Production of elemental arsenic and arsine |
| title_sort |
tio 2-photocatalytic reduction of pentavalent and trivalent arsenic: production of elemental arsenic and arsine |
| url |
http://hdl.handle.net/20.500.12110/paper_0013936X_v46_n4_p2299_Levy |
| work_keys_str_mv |
AT levyik tio2photocatalyticreductionofpentavalentandtrivalentarsenicproductionofelementalarsenicandarsine AT mizrahim tio2photocatalyticreductionofpentavalentandtrivalentarsenicproductionofelementalarsenicandarsine AT ruanog tio2photocatalyticreductionofpentavalentandtrivalentarsenicproductionofelementalarsenicandarsine AT zampierig tio2photocatalyticreductionofpentavalentandtrivalentarsenicproductionofelementalarsenicandarsine AT requejofg tio2photocatalyticreductionofpentavalentandtrivalentarsenicproductionofelementalarsenicandarsine AT littermi tio2photocatalyticreductionofpentavalentandtrivalentarsenicproductionofelementalarsenicandarsine |
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1807318799043526656 |