Egg white-assisted preparation of inorganic functional materials: A sustainable, eco-friendly, low-cost and multifunctional method

Egg white (EW) has long been a high-quality source of protein for human beings and has also been widely used in food processing and biomedical engineering. Surprisingly, however, given that EW is a sustainable, environment-friendly, low-cost, versatile, readily available, and highly effective functional additive, it has seen relatively little use in the preparation of inorganic functional materials (IFMs). Fortunately, since 2000, and especially since 2010, this situation has been rapidly changing. This perspective article begins by briefly describing EW's protein composition and its functions as a foaming, gelling, reduction, binding and doping agent. It continues with a comprehensive discussion of the strategies for synthesis, mechanisms of formation, and applications for seven IFMs prepared with EW in the last twenty years, including metallic oxides, ferrites, ceramic foams, carbon materials and their composites, metal nanoclusters and metal nanoparticles, biomimetic mineralization of CaCO3, and miscellaneous other IFMs. The article concludes with a summary of the advantages of EW-assisted preparation of IFMs and the bottlenecks that may stand in the way of its rapid development. This case study will provide a reference and guidance for the future use and development of EW in the preparation of IFMs.