Optimising the structure of mesoporous niobium oxide using evaporation-induced self-assembly synthesis method

Nadrah, Peter (author), Knap, Mateja (author), Švara Fabjan, Erika (author), Šuligoj, Andraž (author), Lavrenčič Štangar, Urška (author), Dražić, Goran (author), Novak Tušar, Nataša (author), Sever Škapin, Andrijana (author)

To increase the photocatalytic performance of Niobium(V) oxide (Nb$_2$O$_5$) it is necessary to increase its accessible surface area. The evaporation-induced self-assembly (EISA) synthesis method is well suited for the synthesis of mesoporous structures, but the optimisation of synthesis parameters for Nb$_2$O$_5$ is still limited. In this study, we demonstrate that the synthesis parameters — duration of evaporation, airflow rate, relative humidity and water content in the reaction mixture — significantly affect the specific surface area, mesoporous structure and photocatalytic performance of isopropanol oxidation into acetone of Nb$_2$O$_5$. Our results show that a combination of long evaporation duration, low airflow rate, low relative humidity and moderate water content are needed to obtain material with the highest specific surface area (145 m$^2$ g$^{−1}$) and a narrow hysteresis loop in the N$_2$ sorption isotherm. This material exhibits four times higher photocatalytic activity compared to materials synthesised under less favourable conditions (14.3–17.7 μmol h$^{−1}$ compared to 3.7 μmol h$^{−1}$). We also show that the ordered mesoporous structure plays an important role in improving the photocatalytic performance: the materials with a higher degree of order exhibit about two times higher activity than the materials with a lower degree of order with the same specific surface area (10.4–12.1 μmol h$^{−1}$ compared to 4.9–7.9 μmol h$^{−1}$). These results provide valuable insights for optimising the synthesis of mesoporous niobium oxide to increase both the specific surface area and photocatalytic performance.

• Language: English
• Keywords: Nb$_2$O$_5$, mesoporous material, evaporation-induced self-assembly, photocatalysis
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: 9 str.
• Numbering: Vol. 402, art. 113994
• PID: 20.500.12556/RUL-182858
• UDC: 54
• ISSN on article: 1873-3093
• DOI: 10.1016/j.micromeso.2025.113994
• COBISS.SI-ID: 263282691
• Publication date in RUL: 26.05.2026

Record is a part of a journal

• Title: Microporous and mesoporous materials
• Publisher: Elsevier
• ISSN: 1873-3093
• COBISS.SI-ID: 22924293

Licences

• License: CC BY-NC 4.0, Creative Commons Attribution-NonCommercial 4.0 International
• Link: http://creativecommons.org/licenses/by-nc/4.0/
• Description: A creative commons license that bans commercial use, but the users don’t have to license their derivative works on the same terms.

Secondary language

• Language: Slovenian
• Keywords: Nb$_2$O$_5$, mezoporozni material, samourejanje z odparevanjem topila, fotokataliza