Flexible, cuttable, origami-enabling ceramic nanofiber mat for visible light-driven catalysts

• Published in: Applied surface science 2024-01, Vol.643, p.158711, Article 158711
• Main Authors: Seo, Ho Jun, Im, Eunmi, Myung, Yoon, Min, Yuho, Hyun, Dong Choon, Moon, Geon Dae
• Format: Article
• Language: English
• Subjects: Ceria; Electrospinning; Flexible ceramic nanofiber; Titania; Visible-light responsive photocatalyst
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2023.158711

[Display omitted] •A new kind of flexible ceramic oxide is fabricated as nanofiber mats consisting of two different phases (CeO2–TiO2 [CTO]) with controllable composition.•The CTO nanofibers can be cut into various shapes with high mechanical endurability such as bending, folding, and origami.•The high visible light responsive nature makes the CTO nanofiber an efficient photocatalyst for the degradation of organic pollutants.•The photocatalytic activity of the oxide ceramic mats is closely related to energy band positions and Ce3+ content. Despite possessing abundant potential, the brittleness of oxide ceramic nanofibers limits their use in self-standing flexible photocatalysts with easy separation/recycling and customized shaping. Here, we have reported a novel flexible ceramic constructed using electrospinning of metal oxide nanofiber mats of two different phases (CeO2–TiO2 [CTO]) with controllable composition. Although pure TiO2 and CeO2 nanofibers are too brittle to endure bending, CTO nanofibers show enhanced mechanical properties that make them flexible, bendable, cuttable, and origami-enabled. To study mechanical resilience and nanofiber structures, we have made a series of CTO nanofiber mats with different ratios of TiO2 and CeO2. The results reveal that the heterogeneous TiO2 and CeO2 interface creates stress transfer pathways, while the amorphous TiO2 phase absorbs stress. The CTO nanofiber mats can act as an efficient photocatalyst for the degradation of organic pollutants under visible light. The photocatalytic activity of the oxide ceramic mats is closely related to energy band positions and Ce3+ content. The decrease in the band gap of the CTO nanofiber mats enables the absorption of visible light, and the conduction band is positioned adequately to produce oxygen radicals via electron transfer. Consequently, the efficient degradation of organic pollutants can be achieved in the presence of the CTO nanofiber mat under visible light. Furthermore, the CTO nanofiber mats are coated with other metal oxides to form p–n junction band structures, which facilitate the separation of holes and electrons, resulting in even higher catalytic activity.