Recent progress of phytogenic synthesis of ZnO, SnO 2 , and CeO 2 nanomaterials.

A critical investigation on the fabrication of metal oxide nanoparticles (NPs) such as ZnO, SnO 2 , and CeO 2 NPs synthesized from green and phytogenic method using plants and various plant parts have been compiled. In this review, different plant extraction methods, synthesis methods, characterization techniques, effects of plant extract on the physical, chemical, and optical properties of green synthesized ZnO, SnO 2 , and CeO 2 NPs also have been compiled and discussed. Effect of several parameters on the size, morphology, and optical band gap energy of metal oxide have been explored. Moreover, the role of solvents has been found important and discussed. Extract composition i.e. phytochemicals also found to affect the morphology and size of the synthesized ZnO, SnO 2 , and CeO 2 NPs. It was found that, there is no universal extraction method that is ideal and extraction techniques is unique to the plant type, plant parts, and solvent used.