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Nanoporous gold (np-Au) has found its use in applications ranging from catalysis to biosensing, where pore morphology plays a critical role in performance. While the morphology evolution of bulk np-Au has been widely studied, knowledge about its thin-film form is limited. This work hypothesizes that the mechanical compliance of the thin film substrate can play a critical role in the morphology evolution. Via experimental and finite-element-analysis approaches, we investigate the morphological variation in np-Au thin films deposited on compliant silicone (PDMS) substrates of a range of thicknesses anchored on rigid glass supports and compare those to the morphology of np-Au deposited on glass. More macroscopic (10 s to 100 s of microns) cracks and discrete islands form in the np-Au films on PDMS compared to on glass. Conversely, uniformly distributed microscopic (100 s of nanometers) cracks form in greater numbers in the np-Au films on glass than those on PDMS, with the cracks located within the discrete islands. The np-Au films on glass also show larger ligament and pore sizes, possibly due to higher residual stresses compared to the np-Au/PDMS films. The effective elastic modulus of the substrate layers decreases with increasing PDMS thickness, resulting in secondary np-Au morphology effects, including a reduction in macroscopic crack-to-crack distance, an increase in microscopic crack coverage, and a widening of the microscopic cracks. However, changes in the ligament/pore widths with PDMS thickness are negligible, allowing for independent optimization for cracking. We expect these results to inform the integration of functional np-Au films on compliant substrates into emerging applications, including flexible electronics.

A nanoporous Cu 2 TiSn Heusler alloy is prepared by dealloying-induced phase transformation for electrocatalytic nitrate reduction in neutral conditions and to achieve value-added ammonium phosphomolybdate. [Display omitted] Heusler alloys are a series of well-established intermetallic compounds with abundant structure and elemental substitutions, which are considered as potentially valuable catalysts for integrating multiple reactions owing to the features of ordered atomic arrangement and optimized electronic structure. Herein, a nanoporous copper titanium tin (np-Cu 2 TiSn) Heusler alloy is successfully prepared by the (electro)chemical dealloying transformation method, which exhibits high nitrate (NO 3 –) reduction performance with an NH 3 Faradaic efficiency of 77.14 %, an NH 3 yield rate of 11.90 mg h−1 mg−1 cat , and a stability for 100 h under neutral condition. Significantly, we also convert NO 3 − to high-purity ammonium phosphomolybdate with NH 4 + collection efficiency of 83.8 %, which suggests a practical approach to convert wastewater nitrate into value-added ammonia products. Experiments and theoretical calculations reveal that the electronic structure of Cu sites is modulated by the ligand effect of surrounding Ti and Sn atoms, which can simultaneously enhance the activation of NO 3 −, facilitate the desorption of NH 3 , and reduce the energy barriers, thereby boosting the electrochemical nitrate reduction reaction. [ABSTRACT FROM AUTHOR]

The nanoporous copper (NPC)-copper oxides (Cu2O/CuO)/reduced graphene oxide (rGO) composite structure was synthesized by combining the dealloying process of Cu48Zr47Al5 amorphous ribbons with a microwave-assisted hydrothermal technique at a temperature of 200 °C. The main advantage of the microwave-assisted hydrothermal process is the oxidation of nanoporous copper together with the in situ reduction of graphene oxide to form rGO. The integration of rGO with NPC improves electrical conductivity and streamlines the process of electron transfer. This composite exhibit considerable potential in electrochemical catalysis application, due to the combined catalytic activity of NPC and the chemical reactivity of rGO. Our study relates the transition to n-type rGO in microwave-assisted hydrothermal reactions, and also the development of an electrode material suitable for electrochemical applications based on the p-p-n junction NPC-Cu2O/CuO/rGO heterostructure. To confirm the formation of the composite structure, structural, morphological, and optical techniques as XRD, SEM/EDX, UV-Vis and Raman spectroscopy were used. The composite's electrochemical properties were measured by EIS and Mott-Schottky analyses, showing a charge transfer resistance (Rp) of 250 Ω and indicating the type of the semiconductor properties. The calculated carrier densities of 4.2 × 1018 cm−3 confirms n-type semiconductor characteristic for rGO, and 7.22 × 1018 cm−3 for Cu2O/CuO indicating p-type characteristic. [ABSTRACT FROM AUTHOR]

With an eye on the role of structure size and topology, this study explores the mechanical behavior of nanoporous (NP) Nb made by liquid-metal dealloying. Results from X-ray nanotomography and macro-compression tests confirm that coarsening degrades the yield strength and that Young's modulus deviates from scaling laws developed for NP Au made by dealloying in aqueous media. We find that the scaled genus of NP Nb is lower than what has been reported for NP Au, and this low connectivity provides an obvious explanation for the low modulus. Furthermore, the structural dispersion implies that additional structural descriptors should be acknowledged.

Refinement of nanoporous Cu (NP Cu) by the addition of Polyvinylpyrrolidone (PVP) in HF solution during dealloying of Ti40.6Zr9.4Cu40.6Ni6.3Sn3.1 amorphous ribbons and effect of the surface coverage of Cu2O nanowires obtained by immersing NP Cu in dehydrated ethanol on the photodegradation of methyl orange (MO) pollutants were investigated. The sizes of pores and ligaments of NP Cu decrease significantly with the increase of PVP concentration in the dealloying solutions, accompanied by a drastic decrease in the surface diffusivity and the dislocation defect densities. The surface coverage of Cu2O nanowires becomes higher with an increase of the PVP reagents. The Cu2O nanowires@nanoporous Cu (Cu2O@NP Cu) catalysts show excellent photocatalytic activity towards the degradation of MO under the sunlight due to the existence of large amounts of heterojunctions between Cu2O nanowires and Cu ligaments in nanoscale.

The development of an inexpensive electrocatalyst with good performance for hydrogen evolution reaction (HER) is important and challenging. In this work, a method to prepare an efficient electrocatalyst by dealloying the amorphous Ti 37 Cu 60 Pt 3 alloy in HF was proposed, and a unique nanostructured catalyst for HER under alkaline conditions was successfully prepared. The effect of the dealloying time on the microstructure and HER properties was investigated. The HER performance increases with dealloying time until 40 min. The addition of 3 at.% Pt to Ti 40 Cu 60 further decreases the overpotential at a current density of 10 mA cm−2 and Tafel slopes from 280 mV and 91mV/dec to 63 mV and 45 mV/dec, respectively. The improved electrocatalytic performance was attributed to the formation of rough surface, Cu/Cu 2 O interface and grain boundaries, and the synergistic effect of Pt and Cu, which increases the specific surface area, decreases the charge transfer resistance and improves the intrinsic activity. • Self-supported catalyst was prepared via dealloying TiCuPt amorphous alloy. • Dealloyed TiCuPt nano-alloys exhibited excellent HER catalytic performance. • Dealloying adjusted the microstructure of catalyst surface. • Pt–Cu synergistic effect improved the HER activity. [ABSTRACT FROM AUTHOR]

Tailoring the surface structure of the mesoporous metal catalysts is pivotal for influencing both the catalytic activity and selectivity. Through the dealloying of bimetallic alloys, surface modification is achieved by dissolving unstable components, thereby forming a multitude of catalytically active sites. In this study, highly enhanced electrocatalysts are fabricated via chemical etching of mesoporous AuCu alloy nanoparticles prepared through the self‐assembly of micelles. The presence of large mesoporosity (>10 nm) with rich defect sites on the surface, along with the synergistic effect arising from the AuCu bimetallic alloy, effectively boosts electrocatalytic performance for the ethanol oxidation reaction. This strategy demonstrates a promising strategy to further enhance the catalytic performance of Au‐based mesoporous nanoparticles by eliminating the unstable metal component and refining the mesoporous structure with an abundance of various active sites. [ABSTRACT FROM AUTHOR]

The electrocatalytic performance of a Fe65Co10Si12.5B12.5 Fe-based compounds toward alkaline hydrogen evolution reaction (HER) is enhanced by dealloying. The dealloying process produced a large number of nanosheets on the surface of NS-Fe65Co10Si12.5B12.5, which greatly increased the specific surface area of the electrode. When the dealloying time is 3 h, the overpotential of NS-Fe65Co10Si12.5B12.5 is only 175.1 mV at 1.0 M KOH and 10 mA cm−2, while under the same conditions, the overpotential of Fe65Co10Si12.5B12.5 is 215 mV, which is reduced. In addition, dealloying treated electrodes also show better HER performance than un-dealloying treated electrodes. With the increase in Co doping amount, the overpotential of the hydrogen evolution reaction decreases, and the hydrogen evolution activity is the best when the addition amount of Co is 10%. This work not only provides a basic understanding of the relationship between surface activity and the dealloying of HER catalysts, but also paves a new way for doping transition metal elements in Fe-based electrocatalysts working in alkaline media. [ABSTRACT FROM AUTHOR]

The development of efficient, robust, and cost‐effective electrocatalysts remains a significant challenge for practical water electrolysis. Here, a metallic glass (MG)‐based catalyst with surface‐enriched Ir and Pt‐alloyed active sites, demonstrating superior electrocatalytic performance, is reported. The dealloyed catalyst, characterized by an Ir and Pt‐rich honeycombed nanoporous surface and an interior flexible MG substrate, can directly serve as a bifunctional electrode, enabling efficient hydrogen and oxygen evolution reactions with low overpotentials of 19 and 223 mV to achieve a current density of 10 mA cm−2, respectively. Notably, the mass activity of the catalyst surpasses that of commercial Pt/C and Ir/C catalysts by 13.9 and 16.5 times, respectively. Additionally, the catalyst exhibits exceptional stability with negligible activity decay even under an ampere‐level current density (i.e., ≥1 A cm−2). Theoretical calculations reveal the optimization of atomic configuration and regulation of electronic interactions through lattice strain induced by the co‐alloying of Ir and Pt, contributing to superior electrocatalytic performance. Furthermore, the unique honeycombed nanoporous architecture, shaped by the surface migration and enrichment of the noble metals, offers abundant active sites for accelerating the electrocatalytic reactions. This work presents a novel approach to cost‐effectively design high‐performance alloy catalysts by engineering surface catalytically active sites. [ABSTRACT FROM AUTHOR]

Nanoporous metals, fabricated via dealloying, offer versatile applications but are typically limited to unimodal porous structures, which hinders the integration of conflicting pore‐size‐dependent properties. A strategy is presented that exploits the homologous temperature (TH)‐dependent scaling of feature sizes to generate hierarchical porous structures through multistep dealloying at varied TH levels, adjusted by altering dealloying temperatures or the material melting points. This technique facilitates the creation of monolithic architectures of bimodal porous nickel and trimodal porous carbon, each characterized by well‐defined, self‐similar bicontinuous porosities across distinct length scales. These materials merge extensive surface area with efficient mass transport, showing improved current delivery and rate capabilities as electrodes in electrocatalytic hydrogen production and electrochemical supercapacitors. These results highlight TH as a unifying parameter for precisely tailoring feature sizes of dealloyed nanoporous materials, opening avenues for developing materials with hierarchical structures that enable novel functionalities. [ABSTRACT FROM AUTHOR]

High‐entropy oxides (HEOs) have been showing great promise in a wide range of applications. There remains a lack of clarity regarding the influence of nanostructure and composition on their Li storage performance. Herein, a dealloying technique to synthesize hierarchical nanoporous HEOs with tunable compositions is employed. Building upon the extensively studied quinary AlFeNiCrMnOx, an additional element (Co, V, Ti, or Cu) is introduced to create senary HEOs, allowing for investigation of the impact of the added component on Li storage performance. With higher specific surface areas and oxygen vacancy concentrations, all their HEOs exhibit high Li storage performances. Remarkably, the senary HEO with the addition of V (AlNiFeCrMnVOx) achieves an impressive capacity of 730.2 mAh g−1 at 2.0 A g−1, which surpasses all reported performance of HEOs. This result demonstrates the synergistic interaction of the six elements in one HEO nanostructure. Additionally, the battery cycling‐induced reconstruction and cation diffusion in the HEOs is uncovered, which results in an initial capacity decrease followed by a subsequent continuous capacity increase and enhanced Li ion diffusion. The results highlight the crucial roles played by both nanoporous structure design and composition optimization in enhancing Li storage of HEOs. [ABSTRACT FROM AUTHOR]

We report in this article, the Dysprosium doping effects on microstructure and mechanical properties of nanoporous metallic gold, synthesized by electrochemical dealloying of Ag70Au30 and Ag70Au29Dy1 alloys. It is shown that these dealloyed nanoporous metallic materials exhibit the mean ligament diameter in a length scale of 5–10 nm. The variation of ligament diameter in pure and Dysprosium doped nanoporous Au with annealing temperature influences their mechanical properties. Higher microhardness value has been obtained around 10 nm ligament diameter on both pure and Dysprosium doped nanoporous gold. The maximum values of Vickers hardness HV obtained from the analysis of indentation diagonals with applied load are close to the HV value reported for bulk gold. Since the nanoporous metallic materials behave in a way like compressible sponge materials, we used the well-known density scaling equation for the determination of ligament yield strength of pure and Dysprosium doped nanoporous gold with ligament diameter. The results obtained have been finally compared with literature reports. [ABSTRACT FROM AUTHOR]

[Display omitted] Engineering platinum-free catalysts for hydrogen evolution reaction (HER) with high activity and stability is essential for electrochemical hydrogen production. In this paper, we report the synthesis of cobalt-doped AlNi 3 /NiO (Co-AlNi 3 /NiO) electrode with three-dimensional nanoporous structure via chemical dealloying method. Density functional theory (DFT) calculations reveal that Co-AlNi 3 /NiO can accelerate water adsorption / dissociation and optimize adsorption–desorption energies of H* intermediates, thus improving the intrinsic HER activity. Both the introduction of Co and Al can efficiently ameliorate the electronic density around Ni sites of NiO and AlNi 3 , which can effectively reduce the energy barrier towards Volmer–Heyrovsky reaction and thus synergistically promote the hydrogen evolution. Benefiting from the large electrochemical active surface area, high electrical conductivity and electronic effect, the nanoporous Co-AlNi 3 /NiO catalyst exhibits remarkable HER activity with an overpotential of 73 mV at a current density of 10 mA cm−2 in alkaline condition, outperforming most of the reported non-precious metal catalysts. The nanoporous Co-AlNi 3 /NiO catalyst can operate continuously over 1000 h at high current densities with a robust stability. This work provides a new vision for the development of low-cost and efficient electrocatalysts for energy conversion applications. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: In the endeavor of searching for highly active and stable electrocatalysts toward overall water splitting, high‐entropy‐alloys have been the intense subjects owing to their advanced physicochemical property. The non‐noble metal free‐standing multiscale porous NiFeCoZn high‐entropy‐alloy is in situ constructed on the surface layer of NiZn intermetallic and Ni heterojunction over nickel foam (NiFeCoZn/NiZn‐Ni/NF) by one scalable dealloying protocal to fulfill the outstanding bifunctional electrocatalytic performances toward overall water splitting. Because of the high‐entropy effects and specific hierarchical porous architecture, the as‐made NiFeCoZn/NiZn‐Ni/ NF displays high intrinsic catalytic activities and durability toward both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media. In particular, the in‐situ construction of bimodal porous NiFeCoZn high‐entropy‐alloy results in the small overpotentials (η1000 = 254/409 mV for HER and OER), low Tafel slopes, and exceptional long‐term catalytic durability for 400 h. Expressively, the electrolyzer constructed with NiFeCoZn/NiZn‐Ni/NF as both cathode and anode exhibits a low cell voltage of 1.72 V to deliver the current density of 500 mA·cm–2 for overall water splitting. This work not only provides a facile and scalable protocol for the preparation of self‐supporting high‐entropy‐alloy nanocatalysts but also enlightens the engineering of high performance bifunctional electrocatalysts toward water splitting. [ABSTRACT FROM AUTHOR]

Coatings based on NiZn and CoZn alloys were obtained by combining electrodeposition and diffusion galvanizing methods. The coatings are homogeneous and uniform, the zinc concentration is between 85.0 to 89.5 at. %, and consist of intermetallic phases of NiZn and CoZn, mainly γ-Ni2Zn11 and γ2-CoZn13. Alkaline etching of coatings is accompanied by selective dissolution of zinc, and the rate of dissolution of coatings increases with time. This dealloying is accompanied by a change in the morphology of the coatings - cracks, pits, and pores of considerable depth are formed. These defects contribute to the formation of galvanic coupling between the coating and the substrate, which leads to an increase in the dissolution rate. The electrochemical behavior of coatings after alkaline etching in the cathodic hydrogen evolution reaction was studied. The cathodic current of hydrogen evolution on coatings alkaline etching increases by 1.5 to 3 times compared to coatings before etching. This effect is greater on Ni-based coatings. Diffusion galva­nizing followed by dealloying is a promising method for creating electrode materials for alkaline electrolysis with hydrogen evolution.

Surface-enhanced Raman Spectroscopy (SERS) is a nondestructive technique for rapid detection of analytes even at the single-molecule level. However, highly sensitive and reliable SERS substrates are mostly fabricated with complex nanofabrication techniques, greatly restricting their practical applications. A convenient electrochemical method for transforming the surface of commercial gold wires/foils into silver-alloyed nanostructures is demonstrated in this report. Au substrates are treated with repetitive anodic and cathodic bias in an electrolyte of thiourea, in a one-pot one-step manner. X-rays absorption fine structure (XAFS) spectroscopy confirms that the AuAg alloy is induced at the surface. The unique AuAg alloyed surface nanostructures are particularly advantageous when served as SERS substrates, enabling a remarkably sensitive detection of Rhodamine B (a detection limit of 10−14 ​M, and uniform strong response throughout the substrates at 10−12 ​M).

This study focuses on the design of a new Ti based multicomponent amorphous alloy for the development of biocompatible implant materials with enhanced hemocompatibility and cytocompatibility. While this class of amorphous alloys has shown its potential for biomedical implant applications, there are major concerns due to the presence of elements such as copper which can lead to cytotoxicity in the human body during long term implantation. Nevertheless, copper is indispensable in the development of an amorphous alloy. Thus, the objective of this work is to selectively remove copper from the surface of the Ti40Cu40Zr11Fe3Sn3Ag3 (at%) amorphous alloy using the dealloying technique and produce a patterned protective passivated surface rich in Ti and Zr oxides. Nitric acid (HNO3) has been found to be effective in depleting copper from the sample surface. Optimization of treatment parameters such as temperature (70 °C and room temperature) yielded drastic differences in the morphology of the samples studied using Field-Emission Scanning Electron Microscopy. The treated sample surface demonstrated good hemocompatibility and cytocompatibility with primary human osteoblast cells (HOb) and human osteosarcoma cell line (Saos-2). Additionally, the treated samples showed higher ability to produce reactive oxygen species with respect to pristine samples, which could be convenient for preserving the implant from bacterial contamination. These findings contribute to the advancement of producing copper-depleted nanostructured Ti based amorphous alloys for biomedical implant applications.

Li-CO2 batteries are among the most intriguing techniques for balancing the carbon cycle, but are challenged by the annoyed thermodynamic barrier of the Li2CO3 decomposition reaction. Herein, we demonstrate the electrocatalytic performances of two-dimensional (2D) CoAl-layer double hydroxide (LDH) nanosheets can be significantly improved by trans-dimensional crosslinking with three-dimensional (3D) multilevel nanoporous (MP)-RuCoAl alloy (MP-RuCoAl alloy ⊥ CoAl-LDH). The MP-RuCoAl alloy⊥CoAl-LDH with multiscale pore channels and abundant nano-heterointerface is directly prepared by controllable etching Al from a Ru-Co-Al master alloy along with simultaneous partial oxidization of Al and Co atoms. The MP-RuCoAl is composed of various intermetallic compounds and Ru with abundant grain boundaries, and forms numerous heterointerface with 2D CoAl-LDH nanosheets. The multiscale porous metallic network benefits mass and electron transportation as well as discharge product storage and enables a rich multiphase reaction interface. In situ differential electrochemical mass spectrometry shows that the mass-to-charge ratio in the charging process is ∼ 0.733 which is consistent with the theoretical value of 3/4, stating that the reversible co-decomposition of Li2CO3 and C can be achieved with the MP-RuCoAl alloy⊥CoAl-LDH. The Ketjen black (KB)/MP-RuCoAl⊥CoAl-LDH battery demonstrates a high cyclability for over 2270 h (227 cycles) with a lower voltage gap stabilized at ∼ 1.3 V at 200 mA·g−1. Our findings here provide useful guidelines for developing high efficiency transition metal based electrocatalysts by coupling with conductive porous substrate for impelling the development of practical Li-CO2 battery systems. [ABSTRACT FROM AUTHOR]

Electrocatalysts significantly boost the oxygen evolution reaction (OER) efficiency in alkaline environments. Our research introduces electrochemically co-deposited and dealloyed Ni–B nanoflakes as efficient OER electrocatalysts. Electrochemical analysis showed that the catalyst reaches a current density of 10 mA/cm2 at a remarkably low overpotential of only 334 mV. After 24 h of chronopotentiometry and 1000 cycles of cyclic voltammetry testing, the catalyst exhibits highly persistent OER performance. According to density functional theory computations, boron atom doping modifies the charge density distribution by extracting electrons from neighboring nickel sites. Such an adjustment of the charge density positively influences the OER process. Further, Bader charge analysis suggests that B doping enhances the hydrophilicity of the surface, which facilitates water molecule adsorption and thus forms the Ni–B catalytic active sites. This work not only effectively reduces the overpotential during electrolysis but also greatly advocates for the practical implementation of catalysts utilizing Ni–B composition. • Ni–B nanoflakes for OER, made by electrochemical synthesis and dealloying, excel in alkaline settings. • Achieves 10 mA/cm2 current density with just 334 mV overpotential. • Stable OER performance for 24h and 1000 cycles confirmed. • DFT shows boron doping improves OER by altering charge density. • Boron doping enhances hydrophilicity via bader analysis, aiding water adsorption on Ni–B catalyst. [ABSTRACT FROM AUTHOR]

Exploring high-efficient and economical electrocatalyst for oxygen evolution reaction (OER) is critical for the electrocatalytic water splitting technology to hydrogen production. Herein, we report a hierarchical nanoporous FeCoZn alloys with different Fe/Co atomic ratios in-situ constructed on bimodal porous NiZn intermetallic and Ni heterojunction over nickel foam (FeCoZn/NF) through a scalable electroplating-annealing-etching strategy. The synergistic effect between multi-elements, multiple interface coupling, and self-supporting seamless porous architecture is beneficial for enhancing the number of active sites but also promoting efficient mass transport and electron transfer. FeCoZn/NF exhibits the superior electrocatalytic activity toward OER with a low overpotential of 440 mV at 1004 mA cm−2 and small Tafel slope of 84.8 mV dec−1. The as-made sample also shows exceptional long-term catalytic stability in alkaline media with 1.0 M KOH of remained under the overpotential of 350 mV for 100 h. Besides, the combined FeCoZn/NF and Pt/C/NF for overall water splitting needs the cell potential of 1.481 V at 10 mA cm−2, along with long-term stability. This work provides implications for the design and preparation of highly active non-noble metal-based multiple alloy electrocatalysts. • Multi-scale porous self-supporting FeCoZn alloy was easily made by dealloying. • In-situ building of FeCoZn alloy on NF greatly reduced the overpotential for OER. • FeCoZn/NF shows the high catalytic stability toward OER in basic medium for 100 h. • The synergy and interface effects facilitate superior OER activity for FeCoZn/NF. [ABSTRACT FROM AUTHOR]

Tailoring the surface structure of the mesoporous metal catalysts is pivotal for influencing both the catalytic activity and selectivity. Through the dealloying of bimetallic alloys, surface modification is achieved by dissolving unstable components, thereby forming a multitude of catalytically active sites. In this study, highly enhanced electrocatalysts are fabricated via chemical etching of mesoporous AuCu alloy nanoparticles prepared through the self‐assembly of micelles. The presence of large mesoporosity (>10 nm) with rich defect sites on the surface, along with the synergistic effect arising from the AuCu bimetallic alloy, effectively boosts electrocatalytic performance for the ethanol oxidation reaction. This strategy demonstrates a promising strategy to further enhance the catalytic performance of Au‐based mesoporous nanoparticles by eliminating the unstable metal component and refining the mesoporous structure with an abundance of various active sites.

Mg-based amorphous alloys exhibit efficient catalytic performance and excellent biocompatibility with a promising application probability, specifically in the field of azo dye wastewater degradation. However, the problems like difficulty in preparation and poor cycling stability need to be solved. At present, Mg-based amorphous alloys applied in wastewater degradation are available in powder and ribbon. The amorphous alloy powder fabricated by ball milling has a high specific surface area, and its reactivity is thousands of times better than that of gas atomized alloy powder. But the development is limited due to the high energy consumption, difficult and costly process of powder recycling. The single roller melt-spinning method is a new manufacturing process of amorphous alloy ribbon. Compared to amorphous powder, the specific surface area of amorphous ribbon is relatively lower, therefore, it is necessary to carry out surface modification to enhance it. Dealloying is a way that can form a pore structure on the surface of the amorphous alloys, increasing the specific surface area and providing more reactive sites, which all contribute to the catalytic performance. Exploring the optimal conditions for Mg-based amorphous alloys in wastewater degradation by adjusting amorphous alloy composition, choosing suitable method to preparation and surface modification, reducing cost, expanding the pH range will advance the steps to put Mg-based amorphous alloys in industrial environments into practice.

SONY achieved the commercialization of lithium-ion batteries (LIBs) in 1991. Compared with traditional lead-acid and nickel-cadmium secondary batteries, the novel energy storage device offers the advantages of no memory effect, longer cycle life, and higher energy density. The continuous development of electrolytes, electrode structure, and battery production has resulted in the doubling of the energy density of LIBs since 1991. Lithium resources are limited, expensive, and unevenly distributed. Researchers are committed to replacing lithium with other inexpensive alkali metals, such as sodium and potassium, to reduce cost and save lithium resources. Sodium ion batteries (SIBs) and potassium ion batteries (PIBs) have attracted increasing attention because of their relatively low cost and abundant reserves. With the rapid development of electric automobiles, battery anode materials with high energy density have been drawing increasing attention. Owing to their high energy capacity, Group IV elements (Si, Ge, and Sn) and Group V elements (Sb and Bi) are considered appealing anode materials for LIBs, SIBs, and PIBs. Various methods, such as the hydrothermal method, template method, chemical precipitation, and magnetron sputtering method, are used for preparing anode materials. The dealloying technique is considered an effective method to fabricate alkali metal ion battery anode materials because of its scalable production, controllable structure, and low cost. This is a typical process in which the active components in the precursor alloy are selectively removed, with the residual components reorganizing into a nanostructure with specific morphology and space arrangement. The size, dimension, and morphology of battery anode materials play a considerable role in boosting electrochemical performance. The dealloying technique can be used to achieve the dynamic control of structure, morphology, and spatial arrangement by regulating dealloying and subsequent treatment processes. It can be categorized as chemical, electrochemical, liquid metal, and vapor phase dealloying. Thus far, researchers have successfully synthesized several nanomaterials via the dealloying technique, including three-dimensional (3D) nanoporous Si, 3D nanoporous Ge, 2D Si nanosheets, 1D Bi nanorods, and 0D Sb nanoparticles. Compared with bulk materials, dealloyed nanomaterials have large specific surface areas and remarkable structural stability. Hence, when used as anodes for LIBs, SIBs, and PIBs, dealloyed nanomaterial anodes usually deliver outstanding electrochemical performance. This review describes the common classification of dealloying techniques and the representative research progress. Emphasis is placed on the preparation of dealloyed nanomaterials with various dimensions and the application of dealloyed nanomaterials in alkali metal ion batteries. Finally, the development trend of dealloying and its application prospects in energy storage are also discussed.

The nanoporous copper (NPC)-copper oxides (Cu2O/CuO)/reduced graphene oxide (rGO) composite structure was synthesized by combining the dealloying process of Cu48Zr47Al5 amorphous ribbons with a microwave-assisted hydrothermal technique at a temperature of 200 °C. The main advantage of the microwave-assisted hydrothermal process is the oxidation of nanoporous copper together with the in situ reduction of graphene oxide to form rGO. The integration of rGO with NPC improves electrical conductivity and streamlines the process of electron transfer. This composite exhibit considerable potential in electrochemical catalysis application, due to the combined catalytic activity of NPC and the chemical reactivity of rGO. Our study relates the transition to n-type rGO in microwave-assisted hydrothermal reactions, and also the development of an electrode material suitable for electrochemical applications based on the p-p-n junction NPC-Cu2O/CuO/rGO heterostructure. To confirm the formation of the composite structure, structural, morphological, and optical techniques as XRD, SEM/EDX, UV-Vis and Raman spectroscopy were used. The composite’s electrochemical properties were measured by EIS and Mott-Schottky analyses, showing a charge transfer resistance (Rp) of 250 Ω and indicating the type of the semiconductor properties. The calculated carrier densities of 4.2 × 1018 cm−3 confirms n-type semiconductor characteristic for rGO, and 7.22 × 1018 cm−3 for Cu2O/CuO indicating p-type characteristic.

Dealloyed nanoporous platinum (np-Pt) alloy electrocatalysts are advantageous owing to the lower Pt content in the alloy composition, nanoporous architecture with high electrochemically active surface area, and excellent electrocatalytic activity and durability. Chemical, electrochemical or other dealloying methods help to develop commercially relevant np-Pt alloys. Selection of the appropriate precursor alloy composition, dealloying solution concentration and time, and the number and nature of dealloying steps are essential to optimize the desirable properties. We comprehensively review the available information on dealloyed Pt and its binary, ternary, quaternary and high-entropy alloys, nanoparticles and composites. The review presents various Pt alloy types and their dealloying conditions and the current understanding of the mechanism of electrocatalysis at the nanoporous confined spaces. The origin and the factors contributing to the electrocatalytic activity of dealloyed nanoporous electrocatalysts are discussed. The collective information could assist researchers in deriving more efficient and durable dealloyed electrocatalysts in various electrochemical energy applications. [Display omitted] • Dealloyed nanoporous Pt alloy electrocatalysts are comprehensively reviewed. • Binary/ternary/quaternary/high-entropy alloys, nanoparticles and composites are covered. • Various dealloying conditions and the influencing parameters are presented. • Electrocatalysis mechanisms in the nanoporous confined spaces are discussed. [ABSTRACT FROM AUTHOR]

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• Mg-based amorphous alloys shows catalytic performances to degrade azo dye wastewater. • The amorphous alloy powder fabricated by ball milling with a high specific surface area. • Dealloying can provid more reactive sites on the surface of the amorphous surface. Mg-based amorphous alloys exhibit efficient catalytic performance and excellent biocompatibility with a promising application probability, specifically in the field of azo dye wastewater degradation. However, the problems like difficulty in preparation and poor cycling stability need to be solved. At present, Mg-based amorphous alloys applied in wastewater degradation are available in powder and ribbon. The amorphous alloy powder fabricated by ball milling has a high specific surface area, and its reactivity is thousands of times better than that of gas atomized alloy powder. But the development is limited due to the high energy consumption, difficult and costly process of powder recycling. The single roller melt-spinning method is a new manufacturing process of amorphous alloy ribbon. Compared to amorphous powder, the specific surface area of amorphous ribbon is relatively lower, therefore, it is necessary to carry out surface modification to enhance it. Dealloying is a way that can form a pore structure on the surface of the amorphous alloys, increasing the specific surface area and providing more reactive sites, which all contribute to the catalytic performance. Exploring the optimal conditions for Mg-based amorphous alloys in wastewater degradation by adjusting amorphous alloy composition, choosing suitable method to preparation and surface modification, reducing cost, expanding the pH range will advance the steps to put Mg-based amorphous alloys in industrial environments into practice. [ABSTRACT FROM AUTHOR]

The utilization of nanoporous copper (np-Cu) as a metallic actuator has gained attention in recent years due to its cost-effectiveness in comparison to other precious metals. Despite this, the enhancement of np-Cu's actuation performance remains a challenge due to limitations in its strain amplitude and actuation rate. Additionally, np-Cu has been deemed as a promising material for solar absorption due to its localized surface plasmon resonance effect. However, practical applications such as solar steam generators (SSGs) utilizing np-Cu have yet to be documented. In this study, we present the development of hierarchically nanoporous copper (HNC) through the dealloying of a eutectic Al-Cu alloy. The hierarchical structure of the HNC features a combination of ordered flat channels and randomly distributed continuous nanopores, which work in synergy to improve actuation performance. The ordered flat channels, with a sub-micron scale, facilitate rapid mass transport of electrolyte ions, while the nano-sized continuous pores, due to their large specific surface area, enhance the induced strain. Our results indicate that the HNC exhibits improved actuation performance, with a two times increase in both strain amplitude and rate in comparison to other reported np-Cu. Additionally, the HNC, for the first time, showcases excellent solar steam generation capabilities, with an evaporation rate of 1.47 kg·m−2·h−1 and a photothermal conversion efficiency of 92% under a light intensity of 1 kW·m−2, which rivals that of nanoporous gold and silver film. The enhanced actuation performance and newly discovered solar steam generation properties of the HNC are attributed to its hierarchically porous structure. [ABSTRACT FROM AUTHOR]

[Display omitted] The exploration of efficient and stable noble-metal-free electrocatalysts for hydrogen evolution reaction (HER) is of great interest for the development of electrochemical hydrogen production technologies. Herein, nanoporous Ni-based catalyst with Mo and B co-addition (NiMoB) prepared by dealloying is reported as an efficient electrocatalysts for HER. The nanoporous NiMoB achieves an overpotential of 31 mV at 10 mA cm−2, along with exceptional catalytic stability in alkaline electrolyte. Density functional theory (DFT) calculations reveal that the incorporation of Mo and B can synergistically optimize the electronic structure and regulate the adsorption of HER intermediates on the Ni active site, thus accelerating the HER kinetics. This study provides a new perspective for the development of non-precious Ni-based catalysts towards efficient hydrogen energy conversion. [ABSTRACT FROM AUTHOR]

A new approach to produce nanoporous metals has been investigated, which is based on the dealloying of bi- or multi-component alloys. Depletion and pore formation of the alloy substrate are obtained by the transport of certain alloy components at high temperatures via volatile halogen compounds. These halogen compounds are transferred to materials acting as sinks based on their higher affinity to the respective components, and chemically bound there. Transfer via volatile halogen compounds is known from the pack cementation coating process and from high-temperature corrosion in certain industrial atmospheres. The approach was tested on different precursor alloys: Ti-43.5Al-4Nb-1Mo-0.1B (TNM-B1), TiNb42, and AlCu. Both dealloying effects and micro-scale pore formation were observed. The detailed size of the porous structures is in the range of 50 nm for both TNM-B1 and TiNB42 and 500 nm for AlCu. [ABSTRACT FROM AUTHOR]

High-efficiency bifunctional electrocatalysts can reduce the hydrogen and oxygen evolution reaction (HER/OER) overpotential, which is of great significance for hydrogen production by water splitting. However, issues remain with large-scale preparation and a bottleneck for design separation. In this work, we reported on a facile method using a nanostructured transition metal sulfide (TMS) Ni 3 S 2 -V s -P s nanorod (NSVP NR) bifunctional catalyst material, which was prepared by dealloying and doping to obtain novel fuzzy-like NRs with heterostructures in triphasic points. The experimental results and first-principles calculations both revealed that the P-dopants changed the coordination environment between the inner S-vacancy Ni 3 S 2- x NRs and outer Ni 2 P nanoparticles in the heterojunctions of the triphasic points, which as active sites could accelerate the movement of electron charges in the metal catalyst. The NVSP NRs showed excellent adsorption energy results, which on the Ni site were ΔG H* at 0.12 eV for HER and ΔG max at 0.48 eV for OER. The optimized NSVP NRs demonstrated a current density of 100 mA/cm2 at the lowest overpotential of only 148 mV for HER and 311 mV for OER. Moreover, a cell voltage of 1.565 V could achieve 10 mA/cm2 when assembled in 1 M KOH solution for overall water splitting (OWS). Therefore, these findings provide a novel route from traditional dealloying corrosion for creating nanostructures and for producing new energy, offering insight into bifunctional catalyst design and application. [Display omitted] • The fuzzy-like Ni 3 S 2- x /Ni 2 P NRs were prepared by corrosion and doping methods. • NSVP have nice performance cause by the P-dopant substituting S-vacancy sites in triphasic heterojunction. • The NSVP NRs demonstrate superior overall water splitting electrocatalytic activity and stability. [ABSTRACT FROM AUTHOR]

In order to inhibit dendritic growth and improve the cycle stability of lithium metal anodes (LMAs), a 3D Nanoporous Nickel Foam (NP-NF) collector with hierarchical porous structure is designed through a simple modification strategy of Ni Foam (NF). The strategy only involves two steps, i.e. electrodeposition of metal zinc and chemical dealloying to evolve nanoporous structure. The obtained NP-NF possesses hierarchical pores. The large pores of several hundreds of micrometers from Ni foam could facilitate fast Li+ transport in dynamics. The mesopores on the surface of 100 nm to 1 μm could provide spatial confinement for Li deposition. The increased specific surface area could also reduce the local current density of electrode and consequently suppress the growth of dendrites. In addition, the in-situ formed lithophilic NiO on the 3D NP-NF surface can uniformly induce Li+ deposition. Compared to the Ni foam skeleton, 3D NP-NF in LMAs presents a significantly improved Li plating/string stability with a high Coulombic efficiency of 95 % after 350 cycles with plating capacity of 1 mAh cm−2 at a current density of 1 mA cm−2. 3D NP-NF@Li|Li cell shows an ultra-low overpotential of 18 mV during the 500 cycles (1000 h) at a current density of 1 mA cm−2. The 3D NP-NF@Li|LiFePO4 can stably cycle for 300 times with the capacity retention of above 80 % at 1C. This work demonstrates that constructing a micro-nano 3D porous structure collector can inhibit dendritic growth and improve lifespan of LMAs.

Nanoporous silver (np-S) was prepared by free corrosion dealloying of a series of Ag–Al thin films containing between 25 and 73 at.% Al. It was found that precursor composition had an important influence on the nanostructures and morphologies of the np-S. In particular the size of the Ag ligaments systematically decreased from 32 to 13 nm as the Al content was increased over the series. In contrast, there was only a weak effect on pore size, which remained in the range 11–15 nm, with the maximum occurring at about 55 at.% Al. There was however a significant increase in the density of the pores as the Al content of the precursor was increased. The electrical resistivity of the np-S increases with the decrease in ligament size, changing from about 3 × 10−8 Ω m for sponges with ligaments of about 32 nm diameter rising to 30 × 10−8 Ω m for the sponge with the 13 nm ligaments. The surface area of the np-S was estimated by the electrochemical capacitance in KNO3 solutions and was estimated to increase by an order of magnitude compared to a smooth Ag surface. There was a systematic change in the optical properties of the sponges, with a trend towards less metallic behaviour as the ligament size decreased and pore density increased. These changes culminated in the sponge prepared from the 73 at.% Al precursor having non-metallic characteristics with regard to visible and near-infrared light. The volume fraction of metal was estimated to be of the order of 40 ± 5%. Prior annealing of the precursor inhibited dealloying.

The electrocatalytic performance of a Fe65Co10Si12.5B12.5 Fe-based compounds toward alkaline hydrogen evolution reaction (HER) is enhanced by dealloying. The dealloying process produced a large number of nanosheets on the surface of NS-Fe65Co10Si12.5B12.5, which greatly increased the specific surface area of the electrode. When the dealloying time is 3 h, the overpotential of NS-Fe65Co10Si12.5B12.5 is only 175.1 mV at 1.0 M KOH and 10 mA cm−2, while under the same conditions, the overpotential of Fe65Co10Si12.5B12.5 is 215 mV, which is reduced. In addition, dealloying treated electrodes also show better HER performance than un-dealloying treated electrodes. With the increase in Co doping amount, the overpotential of the hydrogen evolution reaction decreases, and the hydrogen evolution activity is the best when the addition amount of Co is 10%. This work not only provides a basic understanding of the relationship between surface activity and the dealloying of HER catalysts, but also paves a new way for doping transition metal elements in Fe-based electrocatalysts working in alkaline media.

Mg-1 wt.% Li-1 wt.% Ca (LX11) and Mg-4 wt.% Li-1 wt.% Ca (LX41) alloys share the same hexagonal closed-packed crystalline structure. However, the differences in microstructure, mechanical properties, and degradation rates between the two alloys are not well understood. Hereby, the above three aspects of LX11 and LX41 alloys were studied via optical microscopy, tensile tests, and electrochemical polarization and electrochemical impedance spectroscopy, together with hydrogen evolution. The concentration of the released Mg2+, Ca2+, and Li+ ions was analyzed using a flame atomic absorption spectrophotometer. Results demonstrated that the LX11 alloy was composed of finer α-Mg grains, fewer twins, and smaller volume fractions of the intermetallic phases Mg2Ca than the LX41 alloy. The increasing Li concentration generated a weak decrease in the yield strength of the Mg–Li–Ca alloys, a remarkable increase in elongation to failure, and a stable ultimate tensile strength. The LX11 alloy had better corrosion resistance than the LX41 alloy. The release rate of the cations (Mg2+, Ca2+, and Li+) varied significantly with time. The release rate of metallic ions in Hank's solution cannot reflect the true corrosion rate of Mg–Li–Ca alloys due to the formation of the precipitated corrosion products and their difference in solubility. The dealloying corrosion mechanism of the Mg2Ca phase in Mg–Li–Ca alloys was proposed.

The microstructure characteristics at different cooling rates and phase extraction treatments of Cu–34.1Ni–4.5P ingots were discussed in this paper. It was found that Cu–34.1Ni–4.5P ingots were composed of Cu and multiple Ni–P phases, including NiP, Ni5P2, Ni5P4 and Ni12P5. With the cooling rates decreasing from 1710 to 52 K/s, the growth of Ni–P dendrites during the solidification process would be gradually taken place, resulting in the coarsening of Ni–P phases to some extent. It was observed that the average ligament width of Ni–P grains was 1.64 μm with cooling rates as 1710 K/s which was 33% lower than 52 K/s, meaning that the lamellar spacings would also been significantly decreased with the increase of solidification rates. Furthermore, a bulk self-supporting porous Ni–P skeleton materials with hierarchical structure were obtained by dealloying of Cu–34.1Ni–4.5P precursor alloys. Meanwhile, the corresponding mechanism for the formation of Ni–P with skeleton structure was also disscussed. [ABSTRACT FROM AUTHOR]

Developing a room-temperature complete oxidation reaction for CO holds great promise in solving the growing air pollution problem, and catalysis is considered an effective way to achieve this goal. Herein, Au nanoparticles were supported in situ on three substratesCo3O4 nanosheets, Mn3O4 octahedrons, and NiO ligamentsthrough dealloying melt-spun Al–TM–Au (TM = Co, Mn, and Ni) alloy ribbons in NaOH solution, followed by subsequent calcination. The experimental results showed that the Au/Co3O4-300 °C sample with Co3O4 as the support material exhibited the best catalytic performance, enabling complete CO conversion at 30 °C (near room temperature). This sample did not decay in catalytic activity even after 110 h of continuous testing in high concentrations of H2O (30 vol %) and CO2 (20 vol %), showing excellent water resistance, CO2 toxicity resistance, and long-term stability. In addition, systematic characterization indicated a strong interaction between Au and Co3O4 nanosheets with a large specific surface area, exposed {112} crystal planes, and high oxygen mobility. This synergy resulted in enhanced electron transfer at their interface, thereby generating elevated concentrations of Auδ+ and surface-active oxygen. Consequently, the Au/Co3O4-300 °C composite exhibited optimal performance among products prepared from the Al–TM–Au alloy systems. Herein, we provide a pathway for developing green and highly active room-temperature catalysts for CO oxidation reactions. [ABSTRACT FROM AUTHOR]

Due to its extremely high theoretical mass specific capacity, silicon is considered to be the most promising anode material for lithium-ion batteries (LIBs). However, serious volume expansion and poor conductivity limit its commercial application. Herein, dealloying treatments of spray dryed Al-Si-Cu-Ni particles are performed to obtain a Cu/Ni co-doped Si-based anode material with a porous nanowire network structure. The porous structure enables the material to adapt to the volume changes in the cycle process. Moreover, the density functional theory (DFT) calculations show that the co-doping of Cu and Ni can improve the capture ability towards Li, which can accelerate the electron migration rate of the material. Based on the above advantages, the as-prepared material presents excellent electrochemical performance, delivering a reversible capacity of 1092.4 mAh g−1 after 100 cycles at 100 mA g−1. Even after 500 cycles, it still retains 818.7 mAh g−1 at 500 mA g−1. This study is expected to provide ideas for the preparation and optimization of Si-based anodes with good electrochemical performance. [ABSTRACT FROM AUTHOR]

Compared to traditional actuators (such as piezoelectric ceramics), metal actuators possess the advantages of a low energy consumption, large strain amplitude, and high strain energy density. However, most of the existing metal actuators with an excellent comprehensive performance are composed of precious metals, which are limited by high costs and have almost no possibility for large-scale production in the future. This study focuses on non-precious metal materials and exploits a one-step chemical dealloying method to prepare bulk nanoporous (NP) CoCuAl actuators (NP-CCA) from Al70Co20Cu10 alloy. The microstructure and actuation properties of the NP-CCA were analyzed in detail. The dense continuous nanoscale pores provide an excellent network connectivity for a large strain response, enabling the NP-CCA to achieve a strain amplitude of up to 1.19% (more than eight and two times that of NP-Pt and NP-Ag, respectively), comparable to precious metal actuators. In addition, the NP-CCA possesses a high strain energy density, which is prominent in many precious metal actuation materials (such as NP-Au, NP-Ag, and NP-Pt). [ABSTRACT FROM AUTHOR]

To address the challenges associated with preparation of nanoporous Cu–Ni (NP‐CuNi) alloys containing high Ni concentrations, a Ni2+‐assisted dealloying strategy is proposed. The proposed strategy involves a three‐stage dealloying process primarily driven by dynamic Ni deposition/dissolution. The Ni concentration in NP‐CuNi is tuned by altering the Ni content of the Cu–Mn precursor alloy and Ni2+ in a H2SO4 solution. The Ni concentration of the nanoporous Cu66.5Ni28.5Mn5 alloy prepared in a H2SO4 + NiSO4 solution is increased by 5.2 times compared to that of the alloy prepared in the H2SO4 solution alone. Moreover, the corrosion resistance test demonstrates a reduction in corrosion current density by 58.3% compared to NP‐Cu. [ABSTRACT FROM AUTHOR]

A new sort of nanoporous palladium has been synthesised by electrochemical dealloying icosahedral Al72Pd20Mn8 quasicrystal. A nanoporous cell-like pattern is formed in the dealloyed samples, with a mean pole size of 8 nm and a cell wall thickness of ∼ 5 nm. The quasicrystal grains decompose into randomly orientated FCC Pd(Al) nanocrystals in the initial stage of dealloying, which assumes a prior mechanism accounting for the final microstructure size. The nanoporous palladium exhibits evident electrocatalytic activity towards the oxidation of ethanol and methanol in alkaline environment, and demonstrates the possible application as a cathode material in Li-O2 batteries. [ABSTRACT FROM AUTHOR]

Micron scale Silicon (Si) powders embedded with nanoparticles were fabricated by dealloying methods and extracted from antimony (Sb)-inoculated Aluminum-10 wt.% Silicon (Al-10Si) alloys. From TEM observation, most of these nanoparticles were not connected with adjacent ones, with radii ranging from 3 to 10 nm. The cycling performance of Si powders with nanoparticles delivered a specific capacity of 105.2 mAh/g after 30 cycles at a current density of 0.05 mA/g, which was 40% higher than those without nanoparticles, due to the formation of preferential channels for electrolytes. Therefore, the micron size Si structures with nanoparticles have shown a potential as highperformance anode materials for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

In order to improve the catalytic efficiency of metal catalysts for borohydride fuel cells, three-dimensional nano-porous Ag/NiO composite catalysts were prepared by dealloying method, with Al-Ag and Al-Ag-Ni as precursor alloys. On the premise of reducing the amount of Ag used, the catalyst has significantly improved its performance of electrocatalytic sodium borohydride oxide by virtue of the addition of NiO and its structural advantages. Among them, the nano porous Ag/NiO catalyst obtained after dealloying the precursor alloy Al90Ag9Ni1 has the best performance in the performance test of electrocatalytic oxidation of sodium borohydride, with a peak current density of 158.72 mA· mg-1, and a catalytic performance improvement of 35% compared to the nano porous Ag (116.88 mA· mg-1). This catalyst provides a feasible improvement method for improving the activity of sodium borohydride fuel cell catalysts and reducing costs.

Highlights Self-supporting Cu film with high porosity was obtained by dealloying of Al98Cu2. Nanoporous Cu (NP-Cu) film shows good hydrophilicity and strong broadband light absorption. NP-Cu film exhibits outstanding solar steam generation and desalination performance.

Highlights Free-standing bimodal porous interpenetrating-phase FeNiZn and FeNi3 intermetallic heterostructure is in situ built on NiFe foam by dealloying way. FeNiZn/FeNi3@NiFe exhibits superior electrocatalytic activities toward both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) with very low overpotentials and prolonged catalytic durability in alkaline medium. The strong synergy between FeNiZn alloy and FeNi3 intermetallic generates modulated electron structure and thus well optimizes the intermediates chemisorption toward OER and HER.