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SM ISO690:2012 KRAMAR, Anastasiia, ANISHCHENKO, Viktor, KUZEMA, Pavlo, SMIRNOVA, Natalia, LAGUTA, Iryna, STAVINSKAYA, Oksana, IVANNIKOV, Roman, LINNIK, Oksana. Photocatalytic activity of titania and iron titanates films in the process of lignin transformation. In: Ecological and environmental chemistry : - 2022, Ed. 7, 3-4 martie 2022, Chișinău. Chisinau: Centrul Editorial-Poligrafic al USM, 2022, Ediția 7, Vol.1, pp. 69-70. ISBN 978-9975-159-07-4.. 10.19261/eec.2022.v1 |
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Ecological and environmental chemistry Ediția 7, Vol.1, 2022 |
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Conferința "Ecological and environmental chemistry 2022" 7, Chișinău, Moldova, 3-4 martie 2022 | |
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CZU: 504.03+544 | |
Pag. 69-70 | |
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Photocatalytic conversion of lignin is a perspective route of ―green technologies‖ in the application of ―raw‖ waste biomass in the synthesis of organic compounds. The efficiency of photocatalytic transformation of lignin depends on its concentration, the composition of the photocatalyst, and light source. The electronic structure of the photocatalyst determines the mechanism of photocatalytic transformations and, in turn, the conversion efficiency and reaction products. The water-soluble fraction of lignin was obtained from plants by extraction in ethanol with the following dissolution of solids in ammonia solution. The photocatalysts were obtained by sol-gel method according to the procedure reported in [1,2]. The photocatalytic experiments were performed using the aqueous solution of lignin liquor at pH 2 in the presence of titania, iron titanate or nitrogen doped iron titanate films under simulated solar light or visible irradiation during 6 h. HPLC results have shown that the products of the lignin conversion, as namely phenol, vanillic acid, resorcinol, p-coumaryl alcohol, have been formed over the photocatalyst as a result of partial depolymerization under light exposure. High yield of phenol formation is observed after photolytic transformation or photosensitization reaction in the presence of TiO2 film under visible light irradiation. Iron titanates films were inactive towards phenol formation under given experimental conditions. The photocatalytic reaction over titania films led to the formation of the mixture of compounds: phenol, vanillic acid, resorcinol and p-coumaryl alcohol whereas the films based on iron titanates exhibited high selectivity towards vanillic acid and p-coumaryl alcohol. It is shown that nitrogen doped iron titanate films can be used for the synthesis of vanillic acid, and iron titanate films showed high-selective formation of p-coumaryl alcohol under irradiation with simulated solar light. The efficiency of lignin depolymerization / conversion according to the LDI MS results was increased over titania and nitrogen-doped iron titanate films under simulated solar light. The most effective transformation of complex polymeric structure of lignin molecule under visible light was observed in the presence of nitrogen doped iron titanates.Acknowledgement .This work was financially supported by National Research Foundation of Ukraine (Project No2020.01/0136 «Efficient use of renewable plant resources and photocatalytic conversion of biomass as eco-innovative approaches for environmental protection and human biosafety»). |
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