Correlation of Defect‐Related Optoelectronic Properties in Zn5(OH)6(CO3)2/ZnO Nanostructures with Their Quasi‐Fractal Dimensionality

Abstract

Hydrozincite (Zn5(OH)6(CO3)2) is, among others, a popular precursor used to synthesize nanoscale ZnO with complex morphologies. For many existing and potential applications utilizing nanostructures, performance is determined by the surface and subsurface properties. Current understanding of the relationship between the morphology and the defect properties of nanocrystalline ZnO and hydrozincite systems is still incomplete. Specifically, for the latter nanomaterial the structure-property correlations are largely unreported in the literature despite the extensive use of hydrozincite in the synthesis applications. In our work, we addressed this issue by studying precipitated nanostructures of Zn5(OH)6(CO3)2with varying quasi-fractal dimensionalities containing relatively small amounts of a ZnO phase. Crystal morphology of the samples was accurately controlled by the growth time. We observed a strong correlation between the morphology of the samples and their optoelectronic properties. Our results indicate that a substantial increase of the free surface in the nanocrystal samples generates higher relative concentration of defects, consistent with the model of defect-rich surface and subsurface layers.

Understanding the Correlation of Crystal Atoms with Photochemistry Property: Zn5(OH)6(CO3)2vs. ZnCO3

“…For ZnCO 3 , the peak at about 1433 cm −1 is assigned to CO 3 2−[6] and the absorption bands in 700–1100 cm −1 correspond to the lattice vibration of CO 3 2− . For Zn 5 (OH) 6 (CO 3 ) 2 , the peak at 1510 cm −1 represents the C−O and the band at 1388 cm −1 is assigned to the CO 3 2 − , the band at 1050 cm −1 corresponds to a symmetric stretching vibration of C−O, and the bands at 837 and 710 cm −1 represent the out of plane bending vibration of O−C‐O and the asymmetric O−C‐O bending vibration, respectively . The results demonstrate the formation of ZnCO 3 and Zn 5 (OH) 6 (CO 3 ) 2 .…”