Effect of PSS on morphology and optical properties of ZnO.

ZnO micrometer-sized rods with tunable aspect ratios and 3D hollow spherical superstructures are selectively fabricated by a simple poly(sodium 4-styrene-sulfonate) (PSS)-mediated hydrothermal crystallization and assembly strategy. When PSS concentration is relatively low (0-0.5 g L), the aspect ratios of as-obtained microrods steadily decrease with increasing PSS concentration due to the selective adsorption of PSS on the polar ZnO (001) crystal plane. When PSS concentration is relatively high (1 g L), 3D nanosheets-built hollow microspheres form probably due to the organic-inorganic interfacial cooperative assembly. Raman, photoluminescence and UV-vis diffuse reflectance spectra show that the optical properties of as-obtained ZnO microstructures are highly related to their specific morphologies.