Atomically Dispersed Intrinsic Hollow Sites of M‐M₁‐M (M₁ = Pt, Ir; M = Fe, Co, Ni, Cu, Pt, Ir) on FeCoNiCuPtIr Nanocrystals Enabling Rapid Water Redox

Abstract

Fabrication of advanced electrocatalysts acting as an electrode for simultaneous hydrogen and oxygen evolution reactions (i.e., HER and OER) in an overall cell has attracted massive attention but still faces enormous challenges. This study reports a significant strategy for the rapid synthesis of high-entropy alloys (HEAs) by pulsed laser irradiation. Two types of intrinsic atomic hollow sites over the surface of HEAs are revealed that enable engaging bifunctional activities for water splitting. In this work, a novel senary HEA electrocatalyst made of FeCoNiCuPtIr facilitates the redox of water at only 1.51 V to achieve 10 mA cm −2 and still remains steadily catalytic and durable after being subjected to a 1m KOH solution for more than 20 h. First-principles calculations reveal that the incorporation of Ir and Pt atoms with neighboring elements donate valence electrons to hollow sites weakening the coupling strength between adsorbate and alloy surface and, consequently accelerating both HER and OER. This work delivers a powerful technique to synthesize highly efficient HEA catalysts and unravels the formation mechanism of active sites across the surface of HEA catalysts.

High‐Entropy Materials for Water Electrolysis

“…[ 18 ] The particle size could be facilely controlled by adjusting the synthesis parameters including substrate, shock temperature and duration, and heating/cooling rate. Lu et al proposed a rapid laser‐pulsed irradiation method to assist the formation of tiny and uniform senary FeCoNiCuPtIr HEA nanocatalysts within just 1 ms. [ 80 ] By tuning the laser irradiation mode and laser impact duration, the particle size could be reduced to the sub‐10 nm range. The FeCoNiCuPtIr sample processed in a rapid and pulsed manner was found to show the smallest size and best catalytic activities toward both the OER and HER.…”

Reasonably constructed nano-alloyed materials as highly efficient electrocatalysts for the hydrogen evolution reaction

“…For alloy material systems, the current research on composition regulation mainly focuses on the synergistic effect (including the synergistic effect between metals, 23,26,27,31,32,34,35,49,50,132–135 alloys and carriers, 54–57,79,80,130,131 and alloys and structures) 92,136–138 doping effect 61,95,97,98,139–142 and multisite effect. 64–72,99–103,143…”

“…For alloy material systems, the current research on composition regulation mainly focuses on the synergistic effect (including the synergistic effect between metals, 23,26,27,31,32,34,35,49,50,[132][133][134][135] alloys and carriers, [54][55][56][57]79,80,130,131 and alloys and structures) 92,[136][137][138] doping effect 61,95,97,98,139-142 and multisite effect. [64][65][66][67][68][69][70][71][72][99][100][101][102][103]143 Synergistic effect. Bonding dissimilar elements to provide synergistic effects is an effective way to improve the Catalysis Science & Technology Mini review performance of metal catalysts.…”

“…One of the most effective ways to improve the HER activity at low Pt dosage is to introduce other inexpensive metals into Pt to create a multisite effect thereby effectively optimizing the adsorption energy of intermediates on the active site and thus improving the electrocatalytic activity. [64][65][66]68,71,72,99,102 Furthermore, considerable research efforts have been focused on exploring cost-effective Pt-free non-precious metal electrocatalysts in order to replace the high-cost Pt-based materials. 67,69,70,100,101 It is worth mentioning that obtaining HEA nanomaterials containing five or more elements is also a heavy research challenge.…”

Ultrafine Bimetallic Nickel–Cobalt Alloy from a Layered Hydroxide for Oxygen Evolution Reaction and Capacitors

“…21,23,34 However, the large-scale application for noble metals faces restrictions due to their high price and limiting access. 35,36 The reactivity of oxygen atoms is linked to the stability and catalytic activity of metal oxides for the OER. 21 Density functional theory (DFT) typically models the OER reaction as four proton-electron combined transfer steps with the thermodynamic bottleneck of forming *OH, *O, and *OOH species as intermediates on the active sites.…”