Recent Advancements in Human Hair Protein-Based Nanomaterials: Applications in Organic Synthesis and Photocatalytic Degradation

Human hair, often overlooked as biowaste, presents a notable environmental challenge because of its disposal as solid waste. However, owing to its abundance and biodegradability, researchers are now focusing on innovative approaches to mitigate its environmental impact. One promising approach involves repurposing human hair to support metal nanoparticles (MNPs), offering a sustainable solution. This is due to its unique fiber structure and composition, which is rich in heteroatoms such as oxygen, sulfur, and nitrogen. Human hair is an ideal candidate for MNPs. Extracted Human hair proteins (e-HHPs) were treated with various metal salts to facilitate the preparation of e-HHP/MNPs. In addition, it serves as a reducing or capping agent for metal-salts. These e-HHP/MNPs demonstrate significant potential for diverse applications, including the catalysis of organic transformations and degradation of organic pollutants. The e-HHP/MNPs acted as catalysts in aza-Michael, oxidation, coupling, and cycloaddition reactions. This innovative approach addresses the environmental concerns associated with human hair disposal, enhances sustainability, and promotes ecological safety by utilizing bio-waste resources.