Engineering Microdomains of Oxides in High‐Entropy Alloy Electrodes toward Efficient Oxygen Evolution

Abstract

One important goal of the current electrocatalysis is to develop integrated electrodes from the atomic level design to multilevel structural engineering in simple ways and low prices. Here, a series of oxygen micro‐alloyed high‐entropy alloys (O‐HEAs) is developed via a metallurgy approach. A (CrFeCoNi)97O3 bulk O‐HEA shows exceptional electrocatalytic performance for the oxygen evolution reaction (OER), reaching an overpotential as low as 196 mV and a Tafel slope of 29 mV dec−1, and with stability longer than 120 h in 1 m KOH solution at a current density of 10 mA cm−2. It is shown that the enhanced OER performance can be attributed to the formation of island‐like Cr2O3 microdomains, the leaching of Cr3+ ions, and structural amorphization at the interfaces of the domains. These findings offer a technological‐orientated strategy to integrated electrodes.

MOF-Derived Ultrathin Cobalt Molybdenum Phosphide Nanosheets for Efficient Electrochemical Overall Water Splitting

“…The long-term stability of CoMoP was further analyzed by CV and chronopotentiometry measurements [ 57 , 58 ]. Figure 4 e shows how the LSV curve of CoMoP after 3000 CV cycles closely resembles that of the first cycle.…”

High‐entropy alloy catalysts: From bulk to nano toward highly efficient carbon and nitrogen catalysis

“…In the meantime, heterogeneous catalysts construction and morphological control are also paramount to further adjusting their catalytic performances. 108,109,[117][118][119][120] For example, Shi et al 107 reported the non-NM HEA as a substrate to disperse, stabilize, and tune NM Pt (active sites) toward significantly improved activity, stability, and low cost. In their design, the surface Pt nanoclusters are anchored on the non-noble HEA core, which ensures high dispersity, stability, and tunability of the surface active sites through high-entropy stabilization and core-shell interactions (Figure 5C).…”

Active Sites Regulation for High-Performance Oxygen Evolution Reaction Electrocatalysts

“…The DFT calculations show that Ni/Co can reduce the barrier potential of rate-determining step (O*→OOH*), and Al sites can promote the electrical conductivity ( Feng et al, 2020 ). Yu et al introduce Cr into representative NiCoFe system to synthesize (CrFeCoNi) 97 O 3 , and Cr ion can be etched during OER to promote the interfacial reconstruction and amorphization, resulting in an improved OER performance with a low overpotential of 196 mV at 10 mA cm −2 and Tafel slope of 29 mV dec −1 ( Chen Z. J. et al, 2021 ). Generally, amorphous structure can offer more active sites and thus exhibit better OER performance compared with their crystalline counterparts.…”