Fabrication of Zinc Oxide Composite Microfibers for Near-Infrared-Light-Mediated Photocatalysis

The fabrication of photocatalysts driven by near-infrared (NIR) light is of great scientific and technological interest to make use of solar energy. NaYF4 codoped with Yb3+ and Tm3+ upconversion nanoparticles are important nanotransducers that transfer NIR photons to high-energy photons (UV/Vis). In this work, we demonstrated an electrospinning technique to synthesize ZnO and porous ZnO composite microfibers embedded with a large amount of NaYF4:Yb/Tm@NaYF4 nanoparticles. The morphologies, chemical compositions, and phase of the as-prepared composites were investigated carefully by using field-emission scanning electron microscopy, TEM, X-ray photoelectron spectroscopy, fluorescence spectroscopy, and XRD. Steady-state and dynamic-state fluorescence spectra were used to demonstrate that the embedded NaYF4:Yb/Tm@NaYF4 core-shell nanoparticles can activate the ZnO nanoparticles under IR irradiation. The ZnO composite microfibers can efficiently transfer the NIR photons to the excited state of ZnO and activate the semiconductor to produce reactive oxygen species to result in the degradation of rhodamineB dyes.