Nanomaterials: A Review of Synthesis Methods, Properties, Recent Progress, and Challenges This review discusses the synthesis methods, properties, and challenges of nanomaterials, focusing on their applications in desalination and water treatment. Dr. Nadeem Baig and his team at the Center of Research Excellence in Desalination & Water Treatment, King Fahd University of Petroleum and Minerals, have explored the development of advanced nanomaterials for various applications, particularly nanocomposite membranes for desalination. The review highlights top-down and bottom-up approaches for synthesizing nanomaterials, emphasizing the challenges in producing defect-free nanomaterials that maintain their unique properties. Nanomaterials are defined as materials with at least one dimension in the range of 1 to 100 nm. They exhibit exceptional properties such as high surface area, unique magnetic, electrical, optical, mechanical, and catalytic characteristics. The review discusses various nanomaterials, including fullerenes, carbon nanotubes, graphene, carbon quantum dots, nanodiamonds, carbon nanohorns, nanoporous materials, core-shell nanoparticles, silicene, antimonene, MXenes, 2D MOF nanosheets, boron nitride nanosheets, layered double hydroxides, and metal-based nanomaterials. The review also addresses the challenges and future perspectives of nanomaterials, emphasizing their potential in various fields such as environmental remediation, energy storage, and medical applications. The review outlines two main synthesis approaches: top-down and bottom-up. Top-down methods include mechanical milling, electrospinning, lithography, sputtering, and arc discharge. Bottom-up methods include chemical vapor deposition (CVD), solvothermal and hydrothermal methods, sol-gel method, soft and hard templating methods, and reverse micelle methods. Each method is discussed in detail, highlighting their advantages and challenges. The unique properties of nanomaterials, such as high surface area, magnetism, quantum effects, and excellent mechanical and electrical properties, make them valuable for various applications. The review also discusses the potential of nanomaterials in catalysis, drug delivery, and energy storage. Despite their promising applications, challenges remain in producing defect-free nanomaterials and ensuring their stability and functionality in practical applications. The review concludes with a discussion on the future perspectives of nanomaterials, emphasizing the need for further research and development to fully harness their potential.Nanomaterials: A Review of Synthesis Methods, Properties, Recent Progress, and Challenges This review discusses the synthesis methods, properties, and challenges of nanomaterials, focusing on their applications in desalination and water treatment. Dr. Nadeem Baig and his team at the Center of Research Excellence in Desalination & Water Treatment, King Fahd University of Petroleum and Minerals, have explored the development of advanced nanomaterials for various applications, particularly nanocomposite membranes for desalination. The review highlights top-down and bottom-up approaches for synthesizing nanomaterials, emphasizing the challenges in producing defect-free nanomaterials that maintain their unique properties. Nanomaterials are defined as materials with at least one dimension in the range of 1 to 100 nm. They exhibit exceptional properties such as high surface area, unique magnetic, electrical, optical, mechanical, and catalytic characteristics. The review discusses various nanomaterials, including fullerenes, carbon nanotubes, graphene, carbon quantum dots, nanodiamonds, carbon nanohorns, nanoporous materials, core-shell nanoparticles, silicene, antimonene, MXenes, 2D MOF nanosheets, boron nitride nanosheets, layered double hydroxides, and metal-based nanomaterials. The review also addresses the challenges and future perspectives of nanomaterials, emphasizing their potential in various fields such as environmental remediation, energy storage, and medical applications. The review outlines two main synthesis approaches: top-down and bottom-up. Top-down methods include mechanical milling, electrospinning, lithography, sputtering, and arc discharge. Bottom-up methods include chemical vapor deposition (CVD), solvothermal and hydrothermal methods, sol-gel method, soft and hard templating methods, and reverse micelle methods. Each method is discussed in detail, highlighting their advantages and challenges. The unique properties of nanomaterials, such as high surface area, magnetism, quantum effects, and excellent mechanical and electrical properties, make them valuable for various applications. The review also discusses the potential of nanomaterials in catalysis, drug delivery, and energy storage. Despite their promising applications, challenges remain in producing defect-free nanomaterials and ensuring their stability and functionality in practical applications. The review concludes with a discussion on the future perspectives of nanomaterials, emphasizing the need for further research and development to fully harness their potential.