Growth of wurtzite ZnO nanorods using different capping agents: Characterization, morphology, and investigation the catalytic activity in some oxindoles and indolyl organics

ZnO nanorods have been prepared through chemical deposition of Zn(OAc)2.2H2O by employing different capping agents, (PEG, MW=2000 and PEG, MW=5000). The fabricated catalyst was characterized by scanning electron microscope (SEM) images and XRD pattern. The results show the one dimensional growth of ZnO nano-rods. The results show that capping agents can control the shape and growth of nano-sized crystals. The vertically aligned ZnO was fabricated by PEG 2000, but PEG 5000 changes the ZnO nano-rods to elbow shape. The synthesized nano-rodes have been utilized as highly efficient catalyst to promote some one-pot multicomponent reactions (MCRs) of indoles consist of symmetrical and unsymmetrical 3,3-di(indolyl)indoline-2-ones and tris(indolyl)methanes synthesis under mild reaction conditions, respectively. Comparison of the catalytic power of these two kinds of synthetic ZnO NRs (2000 & 5000) has also been investigated. Importantly, the catalysts can be recovered from the reaction media and reused for four runs without any activity loss