Design of halloysite-based nanocomposites by electrospinning for water treatment

Titanium oxide (TiO2) nanofibers are interesting for environmental applications, particularly solar energy and water treatment, due to their physical properties, chemical stability, high activity, and strong oxidation capacity. Here, we designed and synthesized halloysite-TiO2 nanocomposite fibers by combining the electrospinning and sol-gel methods. Halloysite was extracted at Tamra (norther-western part of Tunisia). After optimizing the halloysite and TiO2 ratio, we characterized the obtained hybrid materials by thermogravimetric analysis, X-ray diffraction, scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy, Raman spectroscopy, Brunauer-Emmett-Teller method, and X-ray photoelectron spectroscopy. The results confirmed halloysite incorporation into TiO2 nanofibers. Moreover, when we used these halloysite-TiO2 nanocomposite nanofibers as photocatalysts we found that > 91 % of methylene blue and acetaminophen was removed at neutral pH upon UV and visible light irradiation. Reusability tests showed good stability over five cycles under visible light. We also carried out acute toxicity and scavenging tests to monitor the formation of by-products and reactive species during acetaminophen degradation. We found that both O-2(center dot-) and h(+) played a major role in its degradation. Overall, halloysite-TiO2 nanocomposite nanofibers are effective catalysts for the removal of organic dyes and pharmaceutical compounds from water.

Automated summary

In this study, halloysite-TiO2 nanocomposite nanofibers were designed and synthesized using electrospinning and sol-gel methods. The results showed that these nanofibers exhibited high efficacy in removing organic dyes and pharmaceutical compounds at neutral pH, and remained stable after multiple cycles of use.