Simultaneous Multication Exchange Pathway to High-Entropy Metal Sulfide Nanoparticles

Abstract

High entropy materials, which contain a large number of randomly distributed elements, have unique catalytic, electrochemical, and mechanical properties. The high configurational entropy of the randomized elements drives the formation of high entropy materials; therefore, high temperatures and quenching are typically required to stabilize them. Because of this, colloidal nanoparticles of high entropy materials are difficult to synthesize and remain rare, despite their desirable high surface areas and solution dispersibilities. Here, we introduce simultaneous multication exchange as an alternative low-temperature pathway to colloidal nanoparticles of high entropy materials. Roxbyite Cu1.8S nanoparticles react with a substoichiometric mixture of Zn2+, Co2+, In3+, and Ga3+ to produce nanoparticles of the high entropy metal sulfide Zn0.25Co0.22Cu0.28In0.16Ga0.11S. The Zn0.25Co0.22Cu0.28In0.16Ga0.11S nanoparticles are thermally stable, and exchange reactions using fewer cations do not produce the high entropy phase. The use of colloidal nanoparticle cation exchange as a synthetic platform provides both entropic and enthalpic driving forces that, in addition to configurational entropy, enable the formation of high entropy phases at solution-accessible temperatures.

High-entropy materials for catalysis: A new frontier

“…It is worth mentioning that the overall operation conditions of these methods still remain mild and thus benefit scale-up implementations. The third category is to turn to external factors in the liquid phase, such as solvent and ligand molecules in colloidal and polyol solutions ( 33 , 34 ), to facilitate formation of nanoscale HEMs at relatively low temperatures (~200° to 300°C). The surface capping ligands can modify the energetic barrier for homogeneous nucleation and growth, yielding high-entropy nanocrystals instead of phase-segregated heterostructures.…”

“…For instance, cation exchange in colloidal nanocrystals is a process determined by enthalpic and entropic factors involving hard-soft acid-base interactions between metal cationic species and molecular ligands ( 137 ). Inspired by this, Schaak and co-workers ( 33 ) recently introduced multication exchange as a low-temperature pathway to colloidal high-entropy sulfide nanoparticles (Zn 0.25 Co 0.22 Cu 0.28 In 0.16 Ga 0.11 S). A continuous-flow reactor was also developed by Kusada et al ( 138 ), which enables the nonequilibrium, scalable flow synthesis of the IrPdPtRhRu HEA nanoparticles with immiscible elemental combinations.…”

Multi‐Sites Electrocatalysis in High‐Entropy Alloys

“…High-entropy alloy composite materials or other highentropy materials also need to be further expanded, such as carbides, oxides, sulfides, nitrides, halides, diborides, phosphate, and intermetallic compounds. [193][194][195][196][197][198][199][200][201][202][203][204][205] Prepare different high-entropy alloy composite materials, such as core-shell structure, interface structure formed between high-entropy alloy and different substrates, etc., which can also adjust the electronic structure of high-entropy alloy (charge transfer, strain, bonding, etc.) to promote its catalytic effect.…”

Defect‐Rich High‐Entropy Oxide Nanosheets for Efficient 5‐Hydroxymethylfurfural Electrooxidation

“…Nanostructuring represents a promising strategy to enhance the activity of electrocatalysts, since nanostructured catalysts with high surface area can effectively increase the density of the exposed active sites and enhance mass diffusion efficiency, leading to improved electrocatalytic performance [25–28] . However, one of the major obstacles encountered with the fabrication of nanostructured HEOs is the incompatible requirements of achieving high configurational entropy, which is driven by high‐temperature processes, and preventing particle coarsening, which is facilitated by low‐temperature reactions [29] . In addition to expose more active surfaces, defect engineering such as introduction of oxygen vacancies is another effective strategy to promote the electrocatalytic activity [30–34] .…”