https://biointerfaceresearch.com/ 1 of 30 Review Volume 13, Issue 1, 2023, 41 https://doi.org/10.33263/BRIAC131.041 A Comprehensive Review of Nanomaterials: Types, Synthesis, Characterization, and Applications Salem S. Salem 1,* , Eman N. Hammad 2,3 , Asem A. Mohamed 2 , Wagdi El-Dougdoug 3 1 Botany and Microbiology Department, Faculty of Science, AL-Azhar University, Nasr City, Cairo-11884, Egypt 2 Chemistry of Natural and Microbial Products Department, Pharmaceutical Industries Research Division, National Research Centre, Dokki, Giza 12622, Egypt 3 Department of Chemistry, Faculty of Science, Benha University, Benha 13518, Egypt * Correspondence: salemsalahsalem@azhar.edu.eg (S.S.S.); Scopus Author ID 57202162965 Received: 8.11.2021; Accepted: 12.12.2021; Published: 24.01.2022 Abstract: Nanotechnology has infiltrated all sectors due to its unique and evident impacts, which give the scientific community numerous breakthroughs in the medical, agricultural, and other domains. Nanomaterials (NMs) have risen to prominence in technological breakthroughs due to their adjustable physical, chemical, and biological characteristics and superior performance over bulk equivalents. NMs are divided into many categories based on size, composition, capping agents, form, and origin. The capacity to forecast NMs' unique features raises the value of each categorization. As the manufacturing of NMs and industrial uses grow, so does their demand. The purpose of this review is to compare synthetic and naturally occurring nanoparticles and nanostructured materials to determine their nanoscale characteristics and to identify particular knowledge gaps related to the environmental application of nanoparticles and nanostructured materials. The paper review includes an overview of NMs' history and classifications and the many nanoparticles and nanostructured materials sources, both natural and manufactured. Furthermore, the many applications for nanoparticles and nanostructured materials. Keywords: nanotechnology; nanomaterials types; synthesis; characterization; application. © 2022 by the authors. This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). 1. Introduction Nanotechnology is the process of manipulating the shape and size of structures, electronics, and systems at the nanometer scale, i.e., 1 nm to 100 nm (10 -9 m) [1,2]. The unit of nanometer takes its prefix nano from the Greek word "nano" which means "very little" [3]. Their small size gives them more significant surface areas than the corresponding bulk forms, higher reactivity, and a tuneable nature of several properties [4-6]. These special properties have stimulated the growth of nanoscience and the application of NPs in a wide range of fields like biomedicine, cosmetics, electronics, analysis food, environmental and remediation, or paints [7-11]. Nanoscale science and engineering allow us to gain a new level of understanding and control matter at the atomic and molecular dimensions [12]. Nanoscale particles have gotten a lot of attention because of their remarkable electrical, optical, and magnetic properties [13]. These NPs have the dimensions that make them suitable candidates for nanoengineering [14,15]. The desire for novel technology applications in data storage, biomedical sciences, and drug delivery has fueled nanoparticle research [16-19]. Core/shell (CS) NPs, polymer-coated NPs, Ag-NPs, Cu-NPs, Au-NPs, Ni-NPs, Pt-NPs, CuO-NPs, ZnO-NPs, Pd-NPs, Si-NPs, FeO-