Nanomaterials: types, properties, recent advances, and toxicity concerns

Nanomaterials have shown exciting applications in different areas of science and technology because of their special physical and chemical properties compared with bulk materials. They can be synthesized using bottom-up or top-down approaches, and with recent advances, it is possible to have better control on size, shape, and structure by adopting a suitable synthesis approach and manipulating the synthesis conditions. Depending on their type, size, shape, and structure, nanomaterials demonstrate a range of unique electrical, optical, mechanical, magnetic, and antimicrobial properties, which have led to many interesting technological applications. This review provides a summary of the classification, synthesis methods, and properties of nanomaterials. Many newly developed nanomaterials such as layered double hydroxides, metal–organic frameworks, and MXenes have also been reviewed. In the end, a brief overview of the environmental health and safety considerations associated with nanomaterials is provided. This review may serve as a tutorial for readers interested in knowing the background and recent research advances in nanomaterials.