Fabrication of thermo responsive fibrous ZnO/PNIPAM nanocomposites with switchable photocatalytic activity

In this paper, thermo responsive ZnO/PNIPAM nanocomposites were fabricated via electrospinning with the dispersing of ZnO nanoparticles into PNIPAM nanofibers. The effect of the electrospinning parameters on morphology of the nanofibers and the temperatures on the morphology of the nanocomposites was both investigated by SEM–EDS. Furthermore, the photocatalytic kinetics of the nanocomposites was studied by the evaluation of the photocatalytic activities of the nanocomposites above and/or below the lower critical solution temperature (LCST) of PNIPAM. The nanofibers remained the original sizes and shapes above the LCST values, while dissolved obviously and released the embedded ZnO nanoparticles below the LCST values of PNIPAM. The existence of PNIPAM contributed not only the thermo responsive abilities to the nanocomposites, but also the enhanced photocatalytic activities to ZnO nanoparticles, by the detected results of UV–vis spectra of the degradation rates of Rhodamine B and by the calculation results of EPR measurements for the photo induced reactive oxygen species (ROS) of the nanocomposites. Thus, fibrous ZnO/PNIPAM nanocomposites could exhibit switchable and controlled photocatalytic activities through the changing of the temperatures.