One-dimensional hierarchical composite materials based on ZnO nanowires and electrospun blend nanofibers

We employed a combination of two simple and effective methods - electrospinning and hydrothermal synthesis - for fabrication of a novel hierarchical composite material composed of radially oriented ZnO nanowires grown around electrospun blend nanofibers. First, continuous, cylindrical, and randomly oriented nanofibers with diameters of 471 +/- 117 nm were electrospun on glass slides from cellulose acetate/polyvinyl acetate/polyethylene glycol blend. ZnO nanocrystals from the seed solution were then deposited over the prepared fibers that will serve as the nucleation sites for the subsequent radially aligned growth of ZnO nanowires. The amount of ZnO nanowires grown over electrospun nanofibers was determined as 53.4% by weight. Only single crystalline wurtzite nanowires with clear cut hexagonal facets were observed with the length of 329 +/- 38 nm and diameter of 30.4 +/- 6.5 nm. This novel hierarchical nanocomposite exhibited strong UV absorption and photoluminescence in the deep UV region. ZnO nanowires grown on electrospun fibers were found to be highly effective photocatalysts, as indicated by the almost complete removal of the model compound methylene blue in 30 min. In contrast, only 43% of the MB underwent photodegradation in the absence of the catalyst over that period. The pseudo-first order kinetics of the MB photocatalytic degradation is almost ten times faster with the reported material than that without it under UV irradiation.