The main issue concerning UV-vis photoactive nanomaterials employed for decontamination of water containing persistent pollutants, is related to their (re)collection, after use. This problem can be overcome using a mat of conducting nanofibers, mechanically stable, as a support for the photoactive layer, i.e. a metal oxide semiconductor. For the first time we set up a procedure for the synthesis of this multifunctional system and we investigated its application in advanced water treatments. It consists in an electrospun insulating Polyacrilonitrile (PAN) core, which ensures good mechanical properties and high flexibility, a conducting (10-2 S/cm) Polypyrrole (PPY) sheath subsequently covered with ZnO nanocrystals, responsible for the photo-response/activity. The interaction between ZnO and the PPY layer (p-n heterojunction) promotes a selective separation and collection of the photo-generated charge carriers: this combined system results more efficient compared to a non conducting mat. The PAN+PPY+ZnO mats have been tested cyclically toward photodegradation of a target substrate and its removal under irradiation was faster than in absence of the PPY sheath. The synthesis meets various challenging aspects, such as the mild conditions (low T) required during the ZnO layer formation, to preserve the PPY sheath. In order to obtain a homogeneous coverage with ZnO nanocrystals, stable after washing and irradiation, a seeding step was necessarily carried out first, with a Zn-containing precursor. Then, a hydrothermal treatment followed, at low T, in a growth solution. The whole preparation is scalable: all the synthesis steps are facile, cheap and fast. This system can be exploited in many different fields, especially for sensing applications. Other photoactive materials can be homogeneously deposited on the PAN+PPY fibers, via different routes, i.e. electrodeposition.

Flexible and conducting nanofibers functionalized with photoactive ZnO for advanced water treatment

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.