Nanoscience and nanotechnology are interdisciplinary fields that bring together physicists, chemists, materials scientists, and engineers to meet the potential future challenges that humankind will face, including the search for renewable energies for sustainable development and new technologies for carbon capture and environmental protection. Among the current subjects in nanoscience and nanotechnology, nanomaterials are developing fast and explosively and attracting a huge amount of attention. Nanomaterials and their manufacturing technologies have been seamlessly integrated into many applications. They continue to show promising potential and have found application in solar cells, fuel cells, secondary batteries, supercapacitors, air and water purification, and removal of domestic and outdoor air pollutants. Clean energy and environmental applications often demand the development of novel nanomaterials that can provide shortest reaction pathways for the enhancement of reaction kinetics. Understanding the physicochemical, structural, microstructural, and surface properties of nanomaterials is vital for achieving the required efficiency, cycle life, and sustainability in various technological applications.