Nanotechnology, the technology of the 21st century, involves imaging, measuring, modeling, and manipulating matter or fabrication of structures at dimensions of some nanometers. The key point is that at nanoscale, matter changes its properties and behaviour; this induces unusual physical and chemical properties in novel materials very different from the familiar properties of bulk materials. As a main consequence of the exotic properties at nano, the manufactured functional materials can have huge beneficial impacts on improving, even revolutionizing, and many sectors: medicine, transportation, industry, energy, food safety, textiles, security and environmental science, and among many others. In particular, nanotechnology is revealing the potential to develop affordable and renewable energy sources through a new generation of highly efficient materials that reduce energy consumption, improve energy efficiency and give the world cheap access to clean and safe energy