Controlled Synthesis And Properties Of ZnO-dimensional Sheet And Composites

ZnO have attracted vast attention due to their promising optoelectronic properties.In this theme, we report an effective precursor-based route for preparing a sheet-likeZnO assembly composed of small ZnO particles. The process involved frst preparing azinc glycerol precursor and then calcination to transform it into a sheet-like ZnOassembly. The microstructure of the sheet-like ZnO assembly, including the crystallitesize, crystallinity degree and Brunauer–Emmett–Teller (BET) specifc surface area,could be easily tuned by changing the calcination temperature. With an increase incalcination temperature, the crystallinity degree could be improved along with anincrease in the crystallite size. Photocatalytic tests indicated that the as-prepared ZnOsheets showed good activity for photo-degradation of organic dye under UV lightirradiation. ZnO-600(calcination at600℃) exhibited the best photocatalytic activity,which was superior to that of TiO2P25. Furthermore, the sheet-like ZnO assemblycould be readily separated from the reaction system by fltration or low-speedcentrifugation (or natural sedimentation) after photocatalytic use. After5recycles, theZnO-600did not exhibit an obvious loss in activity, confrming its good activity uponrecycling. The combination of X-ray photoelectron spectroscopy (XPS) and BET testindicated that the synergy of the BET surface areas and crystallinity resulted in the goodperformance of the sheet-like ZnO photocatalyst. In particular, due to the sheet-likestructure, the ZnO could effectively combine with Ag particles, resulting in a largeincrease in the photocatalytic activity. Finally, the application of Ag-ZnO as SERSsubstrate was also explored.