## 2 Utilization of Various Nano-Modified Coatings for Corrosion Mitigation  
Nanomaterials (NMs) are substances that demonstrate at least one morphological property at the nanoscale, or within 100 nm, including particulate size, architectural dimension, particle aspect, etc. [60]. These NMs can be found as 2D nanolayers, nanoplatelets or nanosheets as well as OD NPs, 1D nanotubes, nanorods, and nanowires. Particularly in the areas of electrical, photonic, thermal, mechanical, chemical, physical, and magnetic activity, NMs exhibit improved characteristics. Their very tiny dimensions that permit enhanced surface volume fractions, and wide surfaces for efficient interaction are primarily responsible for these behaviors. By applying nanocrystalline structured coatings upon metal substrates, NMs have the potential to reduce the extent of corrosion. Coatings using nano-modifications have been successfully used to lessen the negative impacts of corrosion [61; 62]. The dimensions or sizes of NMs, in conjunction with their intense layering, provide strong adhesion and extremely suitable physical coverage of the protective film. Because there are many different kinds of coating substances and techniques for many different environmental factors and applications, the most widely used method for inhibiting, limiting, minimizing, or mitigating the impacts of corrosion is the nano-modified coating of stacked corrosion inhibitors. These coatings treat the inside or outside surfaces of a particular material at a variety of temperatures, enabling crucial advantages: notably extremely smooth substrates and effective interfacial permeability on the substrates. In the long term, nanocoatings are likely to be less expensive than they initially appear to be, notably when used on a massive scale. This is because of the significant savings that can be realized from greatly reduced repair costs, protection, the prevention of equipment failures, and other factors. Without modifying bulk substances, nano-modified coatings offer an efficient way to address corrosion, abrasion, and wear concerns through surface treatment. Nanostructured coatings are used in a variety of technological systems, such as maritime, aviation, automobile, medical (dental, orthopedic), athletic, architectural, energy, and packaging materials. Research predicts that the market for nanostructured coatings will grow by 20% between 2020 and 2030 [63]. Nanocoatings are created using a variety of synthetic techniques, based on the intended function. In addition to more conventional techniques, including chemical vapor deposition (CVD) and physical vapor deposition (PVD), new techniques like sol-gel and laser cladding processes are also utilized to create nanostructured coatings. Other methods include the spray-coating method and the electrodeposition method [64; 65; 66]. The CVD process entails the deposition of the covering over the preheated substratum after chemical interactions dissociate vaporous or gaseous material adjacent to it. Coating metallic or ceramic materials is a popular application for this technique. The substrate's temperature is important since it may affect how well the coating adheres to the substrate. Owing to the intrinsic characteristics of the CVD process, multi-directional layering of coating substances on a substrate is conceivable. The CVD method is costly for covering wide surfaces because it requires elevated substrate temperatures and a slow pace of precipitation. The intended material is transformed into a gaseous state and then deposited using the PVD technique on a substrate region. The PVD process involves three stages: i) the intended substance evaporates; (ii) the evaporated substance is transported to the substratum; and (iii) the intended substance is deposited as a coating over the substratum. The spray-coating method involves passing the desired substance through a nozzle and depositing it over a substratum to form a coating.