Creative approaches to the design of catalytic nanomaterials are necessary in achieving environmentally sustainable energy sources. Integrating dissimilar metals into a single nanoparticle, NP, offers a unique avenue for customizing catalytic activity and maximizing surface area.
Alloys containing five or more equimolar components with a disordered, amorphous microstructure, referred to as High-Entropy Metallic Glasses, HEMGs, provide tunable catalytic performance based on the individual properties of incorporated metals.Matthew Glasscott, a Ph.D. candidate in Jeffrey Dick's research group, with three undergraduate research colleagues, Pendergast, Hoang, and Bishop, published in Nature Communications, present a generalized strategy to electrosynthesize HEMG-NPs with up to eight equimolar components by confining multiple metal salt precursors to water nanodroplets emulsified in dichloroethane. Upon collision with an electrode, alloy NPs are electrodeposited into a disordered microstructure, where dissimilar metal atoms are proximally arranged.
Matthew and his colleagues also demonstrate precise control over metal stoichiometry by tuning the concentration of metal salt dissolved in the nanodroplet. The application of HEMG-NPs to energy conversion is highlighted with electrocatalytic water splitting on CoFeLaNiPt HEMG-NPs. This system offers multi-functional activity for the hydrogen evolution reaction and the oxygen evolution reaction by combining desirable electrocatalytic properties of transition and noble metals, and this generalized synthetic platform represents a unique opportunity to tune this class of HEMG-NP electrocatalysts for a wide range of reactions.