Exploring the impact of atomic lattice deformation on oxygen evolution reactions based on a sub-5 nm pure face-centred cubic high-entropy alloy electrocatalyst

2020 ◽  
Vol 8 (24) ◽  
pp. 11938-11947 ◽  
Author(s):  
Kang Huang ◽  
Bowei Zhang ◽  
Junsheng Wu ◽  
Tianyuan Zhang ◽  
Dongdong Peng ◽  
...  
Keyword(s):  
Metal Oxides ◽  
Water Splitting ◽  
Oxygen Evolution ◽  
Noble Metals ◽  
High Entropy Alloy ◽  
Lattice Deformation ◽  
High Entropy Alloys ◽  
Atomic Lattice ◽  
High Entropy ◽  
The Impact

Multimetal high-entropy alloys (HEAs) have been recognized as potential catalysts that can possibly replace the conventional metal oxides and noble metals for use in energy conversion and water splitting such as oxygen evolution reactions (OERs).

scholarly journals Low Cost, Easy Scalable High Entropy Alloy (HEA) FeCoNiZnGa for High-Efficiency Oxygen Evolution Reaction (OER)

2020 ◽  
Author(s):  
Lalita Sharma ◽  
Nirmal Kumar ◽  
Rakesh Das ◽  
Khushu Tiwari ◽  
Chandra Sekhar Tiwary ◽  
...  
Keyword(s):  
Water Splitting ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
High Efficiency ◽  
Low Cost ◽  
Synergetic Effect ◽  
High Entropy Alloy ◽  
Electron Microscopic ◽  
High Entropy

<p>Oxygen evolution reaction (OER) is the key step involved both in water splitting devices as well as in rechargeable metal-air batteries and there is an urgent requirement for a highly stable and low-cost material for efficient OER. In this article, for the first time, electrocatalyst based on high entropy alloy (HEA) of FeCoNiZnGa has been reported for OER. Nano-crystalline high entropy alloys materials withdrew the attention of the research academia due to their emerging unique properties due to the cocktail effect and synergetic effect between the constituent elements. The existing materials (IrO<sub>2</sub>, RuO<sub>2</sub>, etc.) being utilized in the OER reaction contain precious metals. Thus, high entropy alloy made up of low-cost elements has been formulated and tested for the OER, which is found to be highly stable and more efficient. The formulation of nanocrystalline HEA (FeCoNiZnGa) utilized a unique recipe casting-cum-comminution (CCC). After electrochemical CV activation, transition metal oxides formation at the HEA surface helps in OER activities. HEA exhibits a low overpotential of 370 mV to achieve a current density of 10 mA cm<sup>-2</sup> with a very small Tafel slope of 71 mV dec<sup>-1</sup> and exceptional long term stability of electrolysis for over 10 h in 1 M KOH alkaline solution, which is extremely stable in comparison to the state-of-the-art OER electrocatalyst RuO<sub>2</sub>. Transmission electron microscopic (TEM) studies after 10 h of long term chronoamperometry testing confirmed high stability of HEA as no change in the crystal structure observed. Our work highlights the great potential of HEA towards oxygen evolution reaction which is primary reaction involved in water splitting.</p>

scholarly journals Low Cost, Easy Scalable High Entropy Alloy (HEA) FeCoNiZnGa for High-Efficiency Oxygen Evolution Reaction (OER)

2020 ◽  
Author(s):  
Lalita Sharma ◽  
Nirmal Kumar ◽  
Rakesh Das ◽  
Khushu Tiwari ◽  
Chandra Sekhar Tiwary ◽  
...  
Keyword(s):  
Water Splitting ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
High Efficiency ◽  
Low Cost ◽  
Synergetic Effect ◽  
High Entropy Alloy ◽  
Electron Microscopic ◽  
High Entropy

<p>Oxygen evolution reaction (OER) is the key step involved both in water splitting devices as well as in rechargeable metal-air batteries and there is an urgent requirement for a highly stable and low-cost material for efficient OER. In this article, for the first time, electrocatalyst based on high entropy alloy (HEA) of FeCoNiZnGa has been reported for OER. Nano-crystalline high entropy alloys materials withdrew the attention of the research academia due to their emerging unique properties due to the cocktail effect and synergetic effect between the constituent elements. The existing materials (IrO<sub>2</sub>, RuO<sub>2</sub>, etc.) being utilized in the OER reaction contain precious metals. Thus, high entropy alloy made up of low-cost elements has been formulated and tested for the OER, which is found to be highly stable and more efficient. The formulation of nanocrystalline HEA (FeCoNiZnGa) utilized a unique recipe casting-cum-comminution (CCC). After electrochemical CV activation, transition metal oxides formation at the HEA surface helps in OER activities. HEA exhibits a low overpotential of 370 mV to achieve a current density of 10 mA cm<sup>-2</sup> with a very small Tafel slope of 71 mV dec<sup>-1</sup> and exceptional long term stability of electrolysis for over 10 h in 1 M KOH alkaline solution, which is extremely stable in comparison to the state-of-the-art OER electrocatalyst RuO<sub>2</sub>. Transmission electron microscopic (TEM) studies after 10 h of long term chronoamperometry testing confirmed high stability of HEA as no change in the crystal structure observed. Our work highlights the great potential of HEA towards oxygen evolution reaction which is primary reaction involved in water splitting.</p>

Preparation, Electrical and Electrochemical Characterizations of CuCoNiFeMn High-Entropy-Alloy for Overall Water Splitting at Neutral-pH

2021 ◽  
Author(s):  
Sivanantham Arumugam ◽  
Hansung Lee ◽  
Sung Won Hwang ◽  
Byungmin Ahn ◽  
In Sun Cho
Keyword(s):  
Water Splitting ◽  
Active Sites ◽  
Surface Composition ◽  
Electrochemical Characterizations ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Equiatomic Composition ◽  
High Entropy ◽  
Neutral Ph ◽  
Overall Water Splitting

High entropy alloys (HEA), the multicomponent (5 or more) alloys with an equiatomic or a near equiatomic composition, provide a unique platform to engineer surface composition and active sites for...

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

2021 ◽  
pp. 2101845
Author(s):  
Zheng‐Jie Chen ◽  
Tao Zhang ◽  
Xiao‐Yu Gao ◽  
Yong‐Jiang Huang ◽  
Xiao‐Hui Qin ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
High Entropy Alloy ◽  
High Entropy

scholarly journals Effect of Copper Addition on the AlCoCrFeNi High Entropy Alloys Properties via the Electroless Plating and Powder Metallurgy Technique

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 540
Author(s):  
Mohamed Ali Hassan ◽  
Hossam M. Yehia ◽  
Ahmed S. A. Mohamed ◽  
Ahmed Essa El-Nikhaily ◽  
Omayma A. Elkady
Keyword(s):  
Compressive Strength ◽  
Powder Metallurgy ◽  
Atomic Radius ◽  
The Other ◽  
High Entropy Alloy ◽  
Coating Process ◽  
High Entropy Alloys ◽  
Powder Metallurgy Technique ◽  
Copper Metal ◽  
High Entropy

To improve the AlCoCrFeNi high entropy alloys’ (HEAs’) toughness, it was coated with different amounts of Cu then fabricated by the powder metallurgy technique. Mechanical alloying of equiatomic AlCoCrFeNi HEAs for 25 h preceded the coating process. The established powder samples were sintered at different temperatures in a vacuum furnace. The HEAs samples sintered at 950˚C exhibit the highest relative density. The AlCoCrFeNi HEAs model sample was not successfully produced by the applied method due to the low melting point of aluminum. The Al element’s problem disappeared due to encapsulating it with a copper layer during the coating process. Because the atomic radius of the copper metal (0.1278 nm) is less than the atomic radius of the aluminum metal (0.1431 nm) and nearly equal to the rest of the other elements (Co, Cr, Fe, and Ni), the crystal size powder and fabricated samples decreased by increasing the content of the Cu wt%. On the other hand, the lattice strain increased. The microstructure revealed that the complete diffusion between the different elements to form high entropy alloy material was not achieved. A dramatic decrease in the produced samples’ hardness was observed where it decreased from 403 HV at 5 wt% Cu to 191 HV at 20 wt% Cu. On the contrary, the compressive strength increased from 400.034 MPa at 5 wt% Cu to 599.527 MPa at 15 wt% Cu with a 49.86% increment. This increment in the compressive strength may be due to precipitating the copper metal on the particles’ surface in the nano-size, reducing the dislocations’ motion, increasing the stiffness of produced materials. The formability and toughness of the fabricated materials improved by increasing the copper’s content. The thermal expansion has increased gradually by increasing the Cu wt%.

A review on phase prediction in high entropy alloys

2021 ◽  
pp. 095440622110089
Author(s):  
Vinay Kumar Soni ◽  
S Sanyal ◽  
K Raja Rao ◽  
Sudip K Sinha
Keyword(s):  
Solid Solution ◽  
Phase Formation ◽  
Single Phase ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Modeling Tools ◽  
High Entropy ◽  
Recent Developments ◽  
Phase Prediction ◽  
The Stability

The formation of single phase solid solution in High Entropy Alloys (HEAs) is essential for the properties of the alloys therefore, numerous approach were proposed by many researchers to predict the stability of single phase solid solution in High Entropy Alloy. The present review examines some of the recent developments while using computational intelligence techniques such as parametric approach, CALPHAD, Machine Learning etc. for prediction of various phase formation in multicomponent high entropy alloys. A detail study of this data-driven approaches pertaining to the understanding of structural and phase formation behaviour of a new class of compositionally complex alloys is done in the present investigation. The advantages and drawbacks of the various computational are also discussed. Finally, this review aims at understanding several computational modeling tools complying the thermodynamic criteria for phase formation of novel HEAs which could possibly deliver superior mechanical properties keeping an aim at advanced engineering applications.

Study on the effect of temperature and strain rate on Ni2FeCrCuAl high entropy alloy: a molecular dynamics study

2021 ◽  
Vol 3 (4) ◽  
pp. 045042
Author(s):  
S Gowthaman ◽  
T Jagadeesha
Keyword(s):  
Molecular Dynamics ◽  
Strain Rate ◽  
Point Defects ◽  
Tensile Deformation ◽  
Variable Temperature ◽  
Effect Of Temperature ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Beneficial Impact ◽  
The Impact

Abstract High entropy alloy has offered significant attention in various material science applications, due to its excellent material features. In this investigation, the mechanical characteristics of Ni2FeCrCuAl High Entropy Alloy (HEA) have been examined under variable temperature and strain rates to analyze its influence over the material features of high entropy alloy through Molecular Dynamics (MD) simulation and it is stated that the formation of various point defects and dislocations are the major cause for the augmentation of tensile deformation which impacts the tensile behavior of high entropy alloy. Moreover, the Radial Distribution Function (RDF) has been examined throughout tensile deformation, to investigate the impact of applied stress over the de-bonding of various atoms and it is found that the strain rate has a greater beneficial impact over the material feature trailed by the temperature outcome, owed to its superior impact on the formation of point defects and shear strain during tensile characterization.

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