A Self‐Supported High‐Entropy Metallic Glass with a Nanosponge Architecture for Efficient Hydrogen Evolution under Alkaline and Acidic Conditions

Abstract

Developing highly efficient and durable electrocatalysts for hydrogen evolution reaction (HER) under both alkaline and acidic media is crucial for the future development of a hydrogen economy. However, state-of-the-art high-performance electrocatalysts recently developed are based on carbon carriers mediated by binding noble elements and their complicated processing methods are a major impediment to commercialization. Here, inspired by the high-entropy alloy concept with its inherent multinary nature and using a glassy alloy design with its chemical homogeneity and tunability, we present a scalable strategy to alloy five equiatomic elements, PdPtCuNiP, into a high-entropy metallic glass (HEMG) for HER in both alkaline and acidic conditions. Surface dealloying of the HEMG creates a nanosponge-like architecture with nanopores and embedded nanocrystals that provides abundant active sites to achieve outstanding HER activity. The obtained overpotentials at a current density of 10 mA cm −2 are 32 and 62 mV in 1.0 m KOH and 0.5 m H 2 SO 4 solutions, respectively, outperforming most currently available electrocatalysts. Density functional theory reveals that a lattice distortion and the chemical complexity of the nanocrystals lead to a strong synergistic effect on the electronic structure that further stabilizes hydrogen proton adsorption/desorption. This HEMG strategy establishes a new paradigm for designing compositionally complex alloys for electrochemical reactions.

In Situ Anchoring Massive Isolated Pt Atoms at Cationic Vacancies of α‐NixFe1‐x(OH)2 to Regulate the Electronic Structure for Overall Water Splitting

“…According to the results of XAS and XPS, it can be concluded that Ni on Pt-Ni 2 Fe 1 -24 loses electrons, which is beneficial to optimize the adsorption strength of the intermediate OOH*. [40] At the same time, the linear relationship between the adsorption energy of the intermediate and the d-band center (Figure S17c, Supporting Information) indicates that Pt single atoms can effectively regulate the electronic structure of the host layer of α-Ni 2/3 Fe 1/3 (OH) 2 , thus optimizing the OER performance. In addition, the relationship is disclosed between the OER overpotential and the d-band center (Figure S17d, Supporting Information), which shows a trend of the "volcano diagram".…”

Review: Multi-principal element alloys by additive manufacturing

“…New alloy systems/compositions should be explored and developed for AM to further expand the MPEAs materials palette and uncover their potential applications, e.g., lightweight MPEA systems consisting of Li, Mg, Al and Si that can be used in aerospace applications. Additionally, precious metal MPEAs, for example IrOsReRhRu and PdPtCuNiP, have shown excellent catalytic performance as have HEA composed of lower cost elements such as FeCoNiAlTi [13,14,170]. If these MPEAs can be successfully designed and fabricated into complex structures with large surface areas using AM technologies, it is anticipated that related applications will become possible and more value will also be added to their practical applications.…”

“…MPEAs have recently enjoyed a rapid development with a clear focus on the design of new alloy systems for potential applications in various industries, such as turbine blades, thermal spray bond coatings, hightemperature molds and dies, radiation-damage resistant materials, and renewable energy industry [6][7][8][9][10][11][12][13][14]. The earliest and most intensely investigated alloy systems are 3d transition metal MPEAs, which are based on the elements Cr, Co, Ni, Fe, Mn, V, and Cu.…”

Selectively Growing a Highly Active Interface of Mixed Nb–Rh Oxide/2D Carbon for Electrocatalytic Hydrogen Production

“…[ 4 ] This is such a serious challenge for convenient, pollution‐free, and efficient use of hydrogen energy, forcing researchers to explore noble‐metal‐free or low precious metal loading electrocatalysts with high catalytic performance, low cost, and scalable synthesis. We are optimistic that various catalysts such as oxides, [ 5 , 6 ] sulfides, [ 7 , 8 ] phosphides, [ 9 , 10 ] and others can be exploited in HER. However, their energetic inefficiency and sluggish kinetics still remain difficult to apply widely in industry.…”