The use of plant extracts in the synthesis of nanoparticles has several advantages over traditional chemical-based synthesis methods. The synthesis of ZnO, Polyethylene Glycol ZnO (PEG), and Chitosen (Chit) ZnO nanoparticles using moringa oleifera leaf extracts as an effective reducing agent is described in this report. The colour of the reaction mixture changes from yellowish brown to white as nano metal oxide forms. Surface modifying agents for ZnO nano oxide included polyethylene glycol and chitosan. UV–Vis and FTIR spectroscopy were used to investigate the optical characteristics of produced nano oxides. The structural, elemental analysis, and morphology of nano oxides were studied using XRD, FESEM, EDAX, and HRTEM techniques. XRD validated the hexagonal wurtzite structure, and the average crystallite size of the ZnO, PEG-ZnO, and Chit-ZnO nanoparticles were 35 nm, 32 nm, and 28 nm, respectively. The band gaps of ZnO, PEG-ZnO, and Chit-ZnO nanoparticles were found to be 3.12 eV, 3.18 eV, and 3.14 eV, respectively, using UV–Visible analysis. ZnO, PEG-ZnO, and Chit-ZnO nanoparticles were found to be generally spherical and nano in size, according to SEM and TEM examination. According to the findings, moringa oleifera leaf extract-assisted ZnO-based nanoparticles are promising materials for various applications.