Bengü Özuğur Uysal

Nanostructures exhibit extraordinary properties, but their full potential is realized only through precise engineering of their surfaces and interfaces. This chapter explores the functionalization of two-dimensional transition metal dichalcogenides (MoS, WS, MoSe, etc.), metal oxide nanoparticles (TiO, ZnO, CeO, SiO, AlO, VO, SnO, etc.), and carbon-based nanostructures, including multi-walled carbon nanotubes (MWCNTs) and graphene derivatives, to tailor their performance for a broad range of advanced applications. Functionalization strategies, including elemental doping, defect engineering, molecular attachment, surface modification, heterostructure formation, and interface engineering, provide effective routes for controlling optical, electronic, electrochromic, photocatalytic, catalytic, and biological properties. These approaches enable precise tuning of charge transport, light absorption, band structure, catalytic activity, and interfacial interactions, resulting in multifunctional nanomaterials with enhanced stability, efficiency, selectivity, and long-term performance. Particular emphasis is placed on hybrid nanocomposites and hydrogel-based systems, where synergistic interactions among nanomaterials significantly improve mechanical strength, biocompatibility, drug delivery efficiency, antibacterial activity, tissue engineering capability, and regenerative potential. The chapter highlights practical design principles that demonstrate how subtle structural and chemical modifications can be translated into application-specific functionality. Representative examples illustrate recent advances in tunable optical and electronic materials, photocatalytic and electrochromic devices, environmental remediation technologies, energy conversion and storage systems, chemical and biological sensing platforms, and advanced biomedical materials. By integrating recent developments in nanomaterial functionalization with practical engineering strategies, this chapter provides readers with a comprehensive understanding of how rational surface and interface design bridges fundamental nanoscience and real-world technologies, offering valuable guidance for the development of next-generation multifunctional nanomaterials across diverse scientific and industrial fields.