Recent advancements in the surface modification and functionalization of magnetic nanomaterials

Magnetic nanomaterials (MNMs) with metallic and semiconducting properties are useful in energy conversion, energy storage, environmental, biomedical, agricultural applications thanks to their large surface area, charge carrier mobility, optical band structure, non-toxic nature, and ability to recover and recycle. However, their poor stability, agglomeration, lack of biocompatibility, fast electron-hole recombination, and leaching in acidic environments restrict bare MNMs for real-time applications. There are several approaches employed to overcome these issues, such as elemental doping, defect formation, nanocomposites, and surface functionalization. Among them, functionalization is one of the promising techniques to alter various properties of MNMs such as specific morphology, size, facet, crystalline phase, and electron mobility. Functionalized MNMs have been explored for various areas of research, including biomedical and environmental applications such as MRI, drug delivery, catalysis, solar hydrogen production, sensors, water and air purification. In this short perspective, promising advances in various functionalization strategies such as surface modification, amino functionalization, polymer functionalization, and biomolecule functionalization, techniques were consolidated, reviewed and their various applications are discussed in detail.