An Emerging Era of Multi-Metallic High-Entropy Photon-Stimulated Materials

The discovery of multi-principal metal materials has gained enormous interest due to their exceptional properties. The combination of five or more metals in one single phase results in synthesizing a material commonly known as high Entropy material (HEM). These materials have exquisite mechanical and catalytic properties owing to unique metallic combinations. The optical properties of various HEM have recently surfaced with exceptional bandgap tunability ranging from the visible to the infrared wavelength spectrum. These optical properties have attracted material scientists to address the current efficiency bottlenecking from bi- or tri-metallic systems. In the quest to deliver efficient performance via High Entropy (HE) configuration, various types of nanostructures are also reported. The major portion of these newly emerged nanostructure categories is comprised of HE-MXene, HE-layered hydroxide, and HE-alloy nanoparticles. Dwelling in these structures for photothermal and photocatalysis are two major interests that have attracted many scientific explorers. There are numerous reviews dedicated to their hardness, toughness, structure, and electrocatalytic properties; a review compiling photo-stimulated/active properties was missing. This review is dedicated to new classes of HE configuration and their role in photo-stimulated studies. The major areas of interest are photoabsorbers, photothermal, photodetectors, photoemitters, photocatalysis, and photochromic materials.