Advanced nickel nanoparticles technology: From synthesis to applications

Over the last decade, nickel nanoparticles (NiNPs) have been investigated for various potential applications due to their superior ferromagnetic properties such as magneto-crystalline anisotropy, high coercive forces, and chemical stability. Therefore, there has been a tremendous enhancement in the synthesis techniques, proposed reaction mechanisms, and applications of NiNPs. This paper presents a recent overview of the synthesis, reaction mechanisms, and applications of NiNPs. NiNPs in the size range of 1-100 nm are synthesized by various methods for research and commercial applications. The synthesis techniques are classified into three main types, namely, top-down, bottom-up, and hybrids of top-down and bottom-up protocols including solvothermal, physical, and chemical approaches. The detailed reaction mechanisms in the formation of NiNPs, especially for biosynthesis techniques, are extensively described. Trends in NiNP applications in fields such as biomedical, catalysis, supercapacitors, and dye-sensitized solar cells are explored. The basic advantages and role of NiNPs as a catalyst for various reactions are illustrated here.