Nanocellulose-Templated Porous Titania Scaffolds Incorporating Presynthesized Titania Nanocrystals

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• 作者：Alesja Ivanova ; Maria C. Fravventura ; Dina Fattakhova-Rohlfing ; Jiri Rathousk媒 ; Liana Movsesyan ; Pirmin Ganter ; Tom J. Savenije ; Thomas Bein
• 刊名：Chemistry of Materials
• 出版年：2015
• 出版时间：September 22, 2015
• 年：2015
• 卷：27
• 期：18
• 页码：6205-6212
• 全文大小：442K
• ISSN：1520-5002

文摘

Nanocrystalline cellulose (NCC) is an abundant biogenic nanomaterial with unique properties that enables the efficient synthesis of mesoporous crystalline titania. We significantly enhance the photocatalytic activity of titania thin films by introducing solvothermally synthesized preformed anatase nanoparticles into a sol鈥揼el based biotemplated titania scaffold. The resulting dual source titania thin films containing different amounts of preformed crystalline species were investigated by time-resolved microwave conductivity (TRMC) measurements and tested in the photocatalytic conversion of 4-chlorophenol. The gradual addition of preformed nanoparticles leads to a consistent increase of the mean size of titania crystalline domains, whereas the porosity of the composite is well-preserved due to the shape-persistent nature of the NCC template. Microwave conductivity studies establish increased photoconductivity of the films containing preformed anatase nanoparticles in comparison to that of films made without the nanoparticles. The synergistic features of the dual source titania, namely the improved crystalline properties brought by the preformed nanocrystals in combination with the high surface area provided by the NCC-templated sol鈥揼el titania, result in a very high photocatalytic activity of the films in the photocatalytic decomposition of 4-chlorophenol. In quantitative terms, the dual source titania films prepared with 75% nanoparticles exhibit a first order degradation rate constant of 0.53 h^鈥? (1.47 脳 10^鈭? sec^鈭?), which strongly outperforms the activity of commercial P90 nanopowder showing a rate constant of 0.17 h^鈥? (0.47 脳 10^鈭? sec^鈭?) under the same conditions.