Nanomaterials have garnered significant scientific attention due to their unique physical, chemical, optical, and electronic properties, which often surpass those of their bulk counterparts. These properties have enabled a wide range of applications across various fields, including electronics, biomedical sciences, environmental technologies, and renewable energy systems. This study provides a comprehensive overview of nanomaterials, including their classification, structural properties, and extraction methods, as well as top-down and bottom-up fabrication approaches, with a particular focus on electronic synthesis methods. Furthermore, key characterisation techniques are discussed, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), ultraviolet-visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR). Special attention should be paid to metal oxide-based nanomaterials, particularly TiO₂ and SnO₂ nanoparticles, due to their promising optical and electronic properties. Furthermore, the review highlights the role of nanomaterials in enhancing the efficiency of dye-sensitive sodium cells (DSSCs) and the viscosity of natural dyes, such as chlorophyll, and environmentally friendly pigments. This overview underscores the potential of nanomaterials in developing renewable energy technologies and the significant progress being made in the field of sustainable energy development.