Energy conversion and environmental protection applications of advanced high-entropy alloy nanomaterials: A perspective

The development of advanced nanomaterials is crucial for the advancement of emerging energy conversion and environmental protection technologies. In recent years, high-entropy alloys (HEAs), as a representative class of novel alloy systems comprising five or more principal elements, have garnered increasing attention due to their unique concepts and exceptional physical and chemical properties. Compared with traditional alloys and bulk pure metals, HEAs exhibit advantages such as broader compositional tunability, remarkable hardness, outstanding corrosion resistance, and superior thermal stability, which naturally endow them with distinctive energy and environmental characteristics. However, the current research on HEAs remains limited, and significant efforts are still needed to explore their full potential in terms of fundamental understanding, synthesis methods, and functional applications. Based on this, this review elucidates the concept of high entropy. It introduces the four core effects (high entropy effect, lattice distortion effect, sluggish diffusion effect and cocktail effect) and provides a detailed overview of various synthetic methods. Additionally, it summarizes recent achievements in the energy and environmental applications of HEAs. Furthermore, we discuss the role of theoretical calculations, machine learning, and other computational tools in advancing HEAs research. Finally, we outline the future trends and development directions of HEAs. It is anticipated that this review will deepen researchers' understanding of HEAs nanomaterials. • This review provides a comprehensive overview of high-entropy alloys (HEAs). • A detailed summary of diverse synthetic strategies for HEAs is presented. • The latest advancements in energy conversion applications of HEAs are systematically discussed. • Environmental protection applications of HEAs are summarized, showcasing their potential in addressing environmental challenges.