Strainer-Separable TiO2 on Halloysite Nanocomposite-Embedded Alginate Capsules with Enhanced Photocatalytic Activity for Degradation of Organic Dyes

Jewon Lee; Sicheon Seong; Soyeong Jin; Jaeyong Kim; Youngdo Jeong; Jaegeun Noh

doi:10.3390/nano12142361

Strainer-Separable TiO₂ on Halloysite Nanocomposite-Embedded Alginate Capsules with Enhanced Photocatalytic Activity for Degradation of Organic Dyes

Nanomaterials (Basel). 2022 Jul 10;12(14):2361. doi: 10.3390/nano12142361.

Authors

Jewon Lee¹, Sicheon Seong², Soyeong Jin^{2

3}, Jaeyong Kim⁴, Youngdo Jeong^{3

5}, Jaegeun Noh^{1

2

6}

Affiliations

¹ Department of Convergence of Nanoscience, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Korea.
² Department of Chemistry, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Korea.
³ Center for Biomaterials, Biomedical Research Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea.
⁴ Department of Physics, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Korea.
⁵ Department of HY-KIST Bio-Convergence, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Korea.
⁶ Institute of Nano Science and Technology, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Korea.

Abstract

Photocatalysis driven by natural sunlight is an attractive approach to removing pollutants from wastewater. Although TiO₂-based photocatalysts using various support nano-materials with high catalytic activity and reusability have been developed for purifying wastewater, the centrifugal separation methods used for the nanocatalysts limit their use for treating large amounts of water. Here, we prepared a TiO₂ nano-catalyst supported on a halloysite nanotube (HNT)-encapsulated alginate capsule (TiO₂@HNT/Alcap) to recapture the catalysts rapidly without centrifugation. The structure of TiO₂@HNT/Alcap was characterized by X-ray diffraction, SEM, and TGA. In our system, the combination of HNTs and alginate capsules (Alcaps) improved the efficiency of adsorption of organic pollutants to TiO₂, and their milli = meter scale structure allowed ultra-fast filtering using a strainer. The TiO₂@HNT/Alcaps showed ~1.7 times higher adsorption of rhodamine B compared to empty alginate capsules and also showed ~10 and ~6 times higher degradation rate compared to the HNT/Alcaps and TiO₂/Alcaps, respectively.

Keywords: alginate capsule; degradation; halloysite nanotubes; organic dyes; photocatalyst; photocatalytic effect; strainer separation; titanium oxide.

Abstract

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