Size-tunable ZnO nanotapes as an efficient catalyst for oxidative chemoselective C-B bond cleavage of arylboronic acids

Herein, we report a simple but effective chemical approach for the synthesis of size-tunable ZnO nanotapes by precipitation method in the presence of phytochemicals present in the flower extract of Lantana samara plant. The electron microscopic study confirmed that the size of ZnO nanotapes can be systematically controlled by varying the concentration of either flower extract or metal ions and the flower extract played the key role in controlling the growth of ZnO nanotapes. The phase and crystalline analysis was carried out by X-ray diffraction method which indicated that ZnO nanostructures are highly crystalline in nature and are free from any impurities. The synthesized ZnO nanostructures exhibited interesting optical properties as investigated by UV-vis absorption and photoluminescence spectroscopy. Further the surface functionalities affect the optical properties of ZnO nanostructures which possess relatively strong UV emissions; a blue emission and a green emission. The synthesized ZnO nanostructures showed excellent catalytic properties in the ipso-hydroxylation of different aryl/hetero-arylboronic acid to phenol in a relatively greener reaction conditions. These catalysts are highly stable and are re-usable upto six cycles of ipso-hydroxylation without losing its catalytic properties.