Hydrothermal synthesis of hexagonal ZnO microstructures in HPMC polymer matrix and their catalytic activities

ZnO microcrystals with hexagonal morphologies are synthesized via a fast and facile hydrothermal route using hexamethylene tetramine (HMTA) as reducing agent and hydroxylpropyl methyl cellulose (HPMC) as morphology directing agent. In the absence of HPMC, hexagonal rod shaped ZnO microcrystals are formed whereas hexagonal bar and both end open hexagonal bar shaped structures are obtained in the presence of different amounts of HPMC. Synthesized ZnO microstructures are characterized using XRD, SEM and fluorescence spectroscopic study. The strong asymmetric blue emission band from ZnO microrod has been explained due to the presence of extended Zni states within the microcrystals. Photocatalytic activities of the microcrystals are investigated by monitoring the photochemical degradation of Methylene Blue. It has been observed that the catalytic efficiency of hexagonal both end open bar shaped ZnO microcrystals is higher than the other ZnO structures.