ZnO flower: Self-assembly growth from nanosheets with exposed {11¯00} facet, white emission, and enhanced photocatalysis

Abstract ZnO flowers consisting of single crystal nanosheets with exposed { 1 1 ¯ 0 0 } facets were fabricated from trisodium citrate via hydrothermal at 180 °C. The single crystal nanosheet has the thickness of about 70 nm and a well-crystalline structure with dominant surfaces as { 1 1 ¯ 0 0 } planes. The site-specific nucleation-growth process contributes to the formation of hierarchical flower-like ZnO structures. The ZnO flowers exhibited white emission. The visible emission gradually decreased with time and the UV emission suggests that the recombined rate of photogenerated electrons and holes of samples varied with the synthesis parameters. The ZnO flowers displayed an enhanced photocatalytic performance compared with ZnO microspheres. The maximized exposure of the reactive { 1 1 ¯ 0 0 } facets also favors the enhanced photocatalytic performance. Additionally, the special loose structural feature with an open microstructure has more important influences on the photocatalytic activity than specific surface area.