Surface Of Zn Research Articles

Work function and electrochemistry of ZnO (wurtzite) single crystals (F-1:L07)

The work functions of two polar surfaces of ZnO (wurtzite), i.e., O-(000–1) and Zn-(0001) are determined by photoelectron spectroscopy in ultrahigh vacuum or in the presence of oxygen or water vapor at near-ambient pressures, and by Kelvin probe in air. The work functions were also determined by Mott-Schottky analysis in aqueous or aprotic (acetonitrile) electrolyte solutions. The values obtained by different techniques and in different environments are much less scattered compared to the fluctuations, reported for TiO2 (anatase or rutile). The Zn-(0001) surface has a smaller work function for all the solid/vacuum and solid/gas interfaces, and also in the acetonitrile electrolyte solution. Solely at the aqueous electrochemical interface, the difference is small or even opposite. We propose a hypothesis that the dissociative water adsorption on the O-(000–1) is responsible for this irregular downshift of the work function in aqueous medium.

Physical and chemical surface modification by laser polishing of CuZn42 parts produced by laser powder bed fusion

The widespread use of Cu-Zn alloys containing lead (Pb) in plumbing applications poses significant health risks due to potential Pb leaching into drinking water. In response to international legislation aimed at reducing or eliminating Pb in metal alloys, there is an increasing demand for environmentally friendly brass. In this experimental work, authors show that during the Laser Beam Powder Bed Fusion (PBF-LB) process of the CuZn42 (CW510L) alloy, small particles only a few microns large mixed with large particles that are hundreds of microns in size, are spattered from the material. Large particles show average Zn/Cu ratio around 0.22, while for small particles it increases up to 3, against a nominal value of 0.72 for the CW510L alloy. The fallout of such particles on the produced part enriches surface of Zn, thus altering the surface chemical composition with an increase in Zn concentration beyond the acceptance limit of 43 at.%. To restore the standard chemical composition of the surface, a treatment based on the ablation of the surface material by a laser beam was proposed. Results clearly show that, after the laser treatment, the chemical composition of the surface is completely restored, and the standard properties recovered.

Suppressing hydrogen evolution reaction by constructing interfacial proton blocking layer for highly reversible zinc anode

Zinc (Zn) anodes are severely threatened by the hydrogen evolution reaction (HER) triggered by highly active water molecules. Motivated by the process of the HER in weakly acidic aqueous, we propose a strategy to construct a proton-blocking layer at the electrode-electrolyte interface by introducing robust hydrogen bonding, aiming to significantly suppress the HER. Isonicotinic acid (INA) possesses N and carboxyl sites that can form strong interactions with protons and can adsorb onto the surface of Zn. Thus, by introducing trace amounts (10 mM) of INA into the electrolyte, proton transfer at the interface can be effectively impeded. In addition, INA can also facilitate Zn uniform growth and inhibit dendrite formation. Consequently, the Zn//Zn symmetrical battery can perform for 3400 h at 1 mA/cm2@1 mAh/cm2, and the coulombic efficiency of the Zn//Cu battery can reach 99.74 % after 1800 cycles. Furthermore, due to the suppression of HER, the Zn//MnO2 batteries achieved high performance of 79.3 mAh/g after 2000 cycles at the current density of 2 A/g. This study provides a new approach to suppress HER and improve the stability of Zn anode.

Microencapsulation of Zn-10 mass% Al alloy phase change material via dry synthesis method

Thermal energy storage (TES) via latent heat storage (LHS) using metal alloy phase change material (PCM) offers advantages in medium-to-high temperature operation around 400 °C and high heat storage capacity. Microencapsulation of alloys as PCMs can mitigate issues of reactivity and improve handling properties of PCM. This research presents the novel development of microencapsulated PCM (MEPCM) with a core of Zn–10 mass% Al that operates around 400 °C. The MEPCMs were synthesized using high-speed impact blending (HIB), where fine AlOOH particles mechanically coat the surface of Zn–10 mass% Al alloy microspheres, resulting in robust surface modification. Subsequent heat-oxidation treatment at 800 °C was performed to obtain stable oxide coating. The HIB treatment resulted in an AlOOH coating containing Zn nanoparticles, which the heat-oxidation process transformed into α-Al2O3 and ZnO nanoparticles. The MEPCMs exhibited heat storage densities, including latent and sensible heat (ΔT=200 °C), that were 1.9 times higher than the capacity of solar salt, which is commonly used as a sensible heat storage material. Furthermore, the MEPCMs maintained their shape and latent heat capacity after 300 and 1000 cyclic tests. These superior MEPCM characteristics hold the potential to significantly advance the development of LHS-based TES systems operating around 400 °C, with applications in energy generation and industrial processes.

Multi‐Group Polymer Coating on Zn Anode for High Overall Conversion Efficiency Photorechargeable Zinc‐Ion Batteries

AbstractThe solar‐driven photorechargeable zinc‐ion batteries have emerged as a promising power solution for smart electronic devices and equipment. However, the subpar cyclic stability of the Zn anode remains a significant impediment to their practical application. Herein, poly(diethynylbenzene‐1,3,5‐triimine‐2,4,6‐trione) (PDPTT) was designed as a functional polymer coating of Zn. Theoretical calculations demonstrate that the PDPTT coating not only significantly homogenizes the electric field distribution on the Zn surface, but also promotes the ion‐accessible surface of Zn. With multiple N and C=O groups exhibiting strong adsorption energies, this polymer coating reduces the nucleation overpotential of Zn, alters the diffusion pathway of Zn2+ at the anode interface, and decreases the corrosion current and hydrogen evolution current. Leveraging these advantages, Zn‐PDPTT//Zn‐PDPTT exhibits an exceptionally long cycling time (≥4300 h, 1 mA cm−2). Zn‐PDPTT//AC zinc‐ion hybrid capacitors can withstand 50,000 cycles at 5 A/g. Zn‐PDPTT//NVO zinc‐ion battery exhibits a faster charge storage rate, higher capacity, and excellent cycling stability. Coupling Zn‐PDPTT//NVO with high‐performance perovskite solar cells results in a 13.12 % overall conversion efficiency for the photorechargeable zinc‐ion battery, showcasing significant value in advancing the efficiency and upgrading conversion of renewable energy utilization.

Multi-Group Polymer Coating on Zn Anode for High Overall Conversion Efficiency Photorechargeable Zinc-Ion Batteries.

The solar-driven photorechargeable zinc-ion batteries have emerged as a promising power solution for smart electronic devices and equipment. However, the subpar cyclic stability of the Zn anode remains a significant impediment to their practical application. Herein, poly(diethynylbenzene-1,3,5-triimine-2,4,6-trione) (PDPTT) was designed as a functional polymer coating of Zn. Theoretical calculations demonstrate that the PDPTT coating not only significantly homogenizes the electric field distribution on the Zn surface, but also promotes the ion-accessible surface of Zn. With multiple N and C=O groups exhibiting strong adsorption energies, this polymer coating reduces the nucleation overpotential of Zn, alters the diffusion pathway of Zn2+ at the anode interface, and decreases the corrosion current and hydrogen evolution current. Leveraging these advantages, Zn-PDPTT//Zn-PDPTT exhibits an exceptionally long cycling time (≥4300 h, 1 mA cm-2). Zn-PDPTT//AC zinc-ion hybrid capacitors can withstand 50,000 cycles at 5 A/g. Zn-PDPTT//NVO zinc-ion battery exhibits a faster charge storage rate, higher capacity, and excellent cycling stability. Coupling Zn-PDPTT//NVO with high-performance perovskite solar cells results in a 13.12 % overall conversion efficiency for the photorechargeable zinc-ion battery, showcasing significant value in advancing the efficiency and upgrading conversion of renewable energy utilization.

In-situ electrochemical mapping of local activity on Zn and Zn-Al alloy electrodes by scanning electrochemical microscopy

Alternating-current scanning electrochemical microscopy (AC-SECM) is introduced to monitor the local activity of Zn and Zn-10Al alloy electrodes. In-situ AC-SECM maps at potentials near the open circuit potential (OCP) in 2 M NaCl (pH 10) indicate that the surfaces of Zn and Zn-10Al alloy electrodes are covered with the passivation layer. When the electrolyte is exchanged with a 0.1 M ethylenediaminetetraacetic acid (EDTA) containing electrolyte, AC-SECM maps at the potential near the OCP clearly reveal the active Zn and the distinct difference between Al- and Zn-rich phases. Thereby, it is demonstrated that EDTA enhances the electrochemical activities of Zn and Zn-10Al alloy electrodes. With shifting the potential to anodic potential of −1.0 V in 0.1 M EDTA containing electrolyte, the interfacial difference between Al- and Zn-rich phases slowly disappears in AC-SECM maps, confirming that the local activity of the surface observed by AC-SECM is only attributed to the metal-EDTA complex. It is noteworthy that the hindered diffusion at the confined space between the tip and the substrate (∼ 10 µm) certainly influences on the local activities of Zn and Zn-10Al alloy electrodes. Additionally, AFM results indicate that the slightly different interactions of EDTA with Al- and Zn-rich phases cause the roughness contrast.

Small Organic Molecules with Anchoring Adsorption Enhance Corrosion Inhibition of Zinc Electrodes in ZnSO4 Medium

AbstractIn this study, trimercapto‐S‐triazine trisodium salt (TMT) with threefold rotational symmetry as a corrosion inhibitor was introduced into 2 mol ⋅ L−1 ZnSO4 medium. By electrochemical measurements, the corrosion inhibition efficiency of the zinc electrodes was 92.52 % when the concentration of TMT corrosion inhibitor was 2 mmol ⋅ L−1. Based on the microstructural characterization and theoretical analysis of Zn electrodes, it was confirmed that S and N atoms of TMT corrosion inhibitor serve as alternately zinc‐philic adsorption sites with sixfold rotational symmetry for the formation of intermolecular complexes. Adsorption energies of TMT on Zn surfaces were calculated and indicated that the bonds of Zn−N and Zn−S promoted anchoring adsorption on sixfold symmetric (002) plane of zinc. Meanwhile, TMT corrosion inhibitor can adsorb Zn2+ from the electrolyte and directionally deposit them on the surface of Zn (002), effectively avoiding the occurrence of dendrites. This study changes the common knowledge that organic corrosion inhibitors must form hydrophobic films to have corrosion inhibition performance, and provides a new approach for using small organic molecules with anchoring adsorption as metal corrosion inhibitors.

Modulating solvated structure of Zn2+ and inducing surface crystallography by a simple organic molecule with abundant polar functional groups to synergistically stabilize zinc metal anodes for long-life aqueous zinc-ion batteries

Aqueous zinc-ion batteries (AZIBs) have attracted significant attention owing to their inherent security, low cost, abundant zinc (Zn) resources and high energy density. Nevertheless, the growth of zinc dendrites and side reactions on the surface of Zn anodes during repeatedly plating/stripping shorten the cycle life of AZIBs. Herein, a simple organic molecule with abundant polar functional groups, 2,2,2-trifluoroether formate (TF), has been proposed as a high-efficient additive in the ZnSO4 electrolyte to suppress the growth of Zn dendrites and side reaction during cycling. It is found that TF molecules can infiltrate the solvated sheath layer of the hydrated Zn2+ to reduce the number of highly chemically active H2O molecules owing to their strong binding energy with Zn2+. Simultaneously, TF molecules can preferentially adsorb onto the Zn surface, guiding the uniform deposition of Zn2+ along the crystalline surface of Zn(002). This dual action significantly inhibits the formation of Zn dendrites and side reactions, thus greatly extending the cycling life of the batteries. Accordingly, the Zn//Cu asymmetric cell with 2 % TF exhibits stable cycling for more than 3,800 cycles, achieving an excellent average Columbic efficiency (CE) of 99.81 % at 2 mA cm−2/1 mAh cm−2. Meanwhile, the Zn||Zn symmetric cell with 2 % TF demonstrates a superlong cycle life exceeding 3,800 h and 2,400 h at 2 mA cm−2/1 mAh cm−2 and 5 mA cm−2/2.5 mAh cm−2, respectively. Simultaneously, the Zn//VO2 full cell with 2 % TF possesses high initial capacity (276.8 mAh/g) and capacity retention (72.5 %) at 5 A/g after 500 cycles. This investigation provides new insights into stabilizing Zn metal anodes for AZIBs through the co-regulation of Zn2+ solvated structure and surface crystallography.

Micro-cracking on the surface of zinc metal improves the cycle performance of aqueous zinc ion batteries

The notorious zinc dendrite is a severe constraint to the practical application of zinc-based batteries, as the metal tips growing vertically in two dimensions on the surface of the electrodes during cycling and loosely packed sharp edges may pierce through the diaphragm, posing a safety hazard. In this study, physical stress extrusion was used to generate micron- or submicron-sized cracks on zinc metal anodes, which significantly increased the specific surface area of the electrodes and mitigated the local current density of the electrodes. Zinc ion fluxes were significantly dispersed, producing a dense Zn2SO4(OH)6-xH2O (ZHS) layer, which differed distinctly from the by-products of the loose upright growth on the surface of Raw Zn (RZn). Additionally, three-dimensional structure of cracked zinc composition allows it to adjust the zinc volume variations during electroplating/stripping, and the abundance of nucleation sites significantly reduces the Zn polarization voltage, resulting in uniform Zn deposition. The average cycle life of the symmetric cell was >400 h at 1 mA cm−2 current density, and nearly 500 cycles at 5 mA cm−2 current density for the asymmetric cell, with an average Coulombic efficiency of 99.3 %. The activation energy substantially declined with the increase in Zn ion flux per unit time (29.615 KJ mol−1 vs. 44.041 KJ mol−1), demonstrating efficient desolvation kinetics. Furthermore, the Crack Zn || V2O5 full cell also exhibits outstanding self-discharge performance, with 85 % capacity retention in a 48 h resting charge/discharge testing, superior to the raw zinc foil anode (78.3 %). Herein, a method of creating microcrack configurations on the surface of zinc anodes using stress extrusion was presented, sparing the current density while optimizing the undesirable growth patterns of ZHS by-products.

Modulating the solvation structure and electrode interface through phosphate additive for highly reversible zinc metal anode

Aqueous zinc-ion batteries (ZIBs) are considered one of the ideal battery systems for large-scale energy storage. However, ZIBs usually show a limited cycle life due to side reactions and dendrite growth at Zn anode. In this study, an ultra-trace amount of β-glycerophosphate sodium (β-GADS) was employed as an additive in aqueous electrolyte to enable highly reversible Zn plating/stripping. For the first time, we show that the phosphate groups in β-GADS could participate in the cation solvation structure, which is more favorable for the de-solvation and diffusion of Zn2+. Moreover, phosphate can absorb on the surface of Zn, and Na+ tend to accumulate at the surface protrusions to form an electrostatic shield that prevent formation of dendrites. Benefitting from the triply synergistic effects of the β-GADS additive, the Zn anode shows the inhibition of dendrites, hydrogen evolution reaction, corrosion reactions, and the formation of by-products. Operated based on 2 M ZnSO4 electrolyte with β-GADS additive, Zn||Zn symmetric cells demonstrated stable cycling for over 1,900 h at 0.5 mA cm−2 and over 1,200 h at a high current density of 5 mA cm−2. The Zn||(NH4)2V7O16·3.2H2O full cell with the above electrolyte also delivered a high capacity and excellent stability for over 1,000 cycles.

Unveiling the mechanism of enhanced water purification by F-Fe-Zn-MCM-41 in O3/PMS

To break the restriction of SO52- as the essential initiator in O3/PMS reaction during water purification, F-Fe-Zn-MCM-41 (FFeZn-M) was designed to enhance ibuprofen (IBP) degradation during O3/PMS process. The great electronegativity difference between Fe and Zn created an electron flow from Zn to Fe, which was further enhanced by electron withdrawing Si-F group. FFeZn-M changed the traditional interaction between PMS and O3. PMS would be adsorbed on the surface of Zn and acted as an electron donor. Meanwhile, O3 received electrons from Fe site and was activated into ROS. With •OH and 1O2 as the main ROS, FFeZn-M/O3/PMS process achieved the complete IBP removal and a 60.9% mineralization rate, which was significantly higher over those of FFeZn-M/O3 and FFeZn-M/PMS processes. FFeZn-M/O3/PMS behaved better at weak acidic and neutral condition rather than the basic condition required by conventional O3/PMS process. This study offered a novel catalyst design strategy for O3/PMS.

Tungsten-based polyoxometalate nanoclusters with remarkable reactive oxygen species-scavenging activity efficiently quenched luminol-based electrochemiluminescence for sensitive detection of Her-2.

This study aimed to develop a quenching-type electrochemiluminescence (ECL) immunosensor for human epidermal growth factor receptor (Her-2) detection. Firstly, Pd/NiFeOx nanoflowers decorated by in situ formation of gold nanoparticles (Au NPs) and 2D Ti3C2 MXene nanosheets were synthesized (AuPd/NiFeOx/Ti3C2) as carriers to load luminol and primary antibodies. Impressively, AuPd/NiFeOx/Ti3C2 with excellent peroxidase-like activity could accelerate the decomposition of the coreactant H2O2 generating more reactive oxygen species (ROSs) under the working potential from 0 to 0.8V, resulting in highly efficient ECL emission at 435-nm wavelengths. Theintroduction of tungsten-based polyoxometalate nanoclusters (W-POM NCs) which exhibit remarkable ROSs-scavenging activity as secondary antibody labels could improve the sensitivity of immunosensors. TheZnO nanoflowers were employed to encapsulate minute-sized W-POM NCs, and polydopamine was self-polymerized on the surface of Zn(W-POM)O to anchor secondary antibodies. The mechanism of the quenching strategy was explored and it was foundthat W-POM NCs could consume ROSs by the redox reaction of W5+ resulting in W6+. The proposed ECL immunosensor displayed a wide linear response range of 0.1pg·mL-1 to 50ng·mL-1, and a low detection limit of 0.036pgmL-1 (S/N = 3). The recoveries ranged from 93.9 to 99.4%, and the relative standard deviation (RSD) was lower than 10%. This finding is promising for the design of detecting new protein biomarkers.

Boosting the tribological properties of PEG200 by a novel face-to-face FeOCl/Zn-MOF lubricant additive

The synergistic effect of nanoparticles can effectively improve the tribological performances of base oils. In this study, a novel lubricant additive by embedding 2D FeOCl on 2D Zn − MOF was reported for the first time in order to boost the tribological performances of polyethylene glycol (PEG200). The FeOCl/Zn − MOF prepared by a facile microwave assisted strategy was found to be a typical flower-like appearance, where FeOCl nanosheets decorated on the surface of Zn − MOF sheets. Owing to the electron transfer and synergistic effect between FeOCl and Zn − MOF, the novel FeOCl/Zn − MOF effectively reduced the coefficient of friction by 48 % and wear scar diameter by 88 % at the loading of 0.4 wt% FeOCl/Zn − MOF in the base oil. The work suggests the face-to-face combination of FeOCl and Zn − MOF for enhanced tribological performances, representing a new strategy to prepare efficient lubricant additives using assembled 2D nanomaterials.

Zincophilic Metal-Organic-Framework Interface Mitigating Dendrite Growth for Highly Reversible Zinc Metal Batteries.

Aqueous Zn-ion batteries are the ideal candidate for large-scale energy storage systems owing to their high safety and low cost. However, the uncontrolled deposition and parasitic reaction of Zn metal anode hinder their commercial application. Here, the 2D metal-organic-framework (MOF) nanoflakes covered on the surface of Zn are proposed to enable dendrite-free for long lifespan Zn metal batteries. The MOF can facilitate the desolvation process to accelerate reaction kinetic due to its special channel structure. The abundant zincopilicity sites of MOF can realize the homogenous Zn2+ deposition. Consequently, their synergetic effect makes the MOF protected Zn anode good electrochemical performance with a long cycle life of 1400h at 1mA cm-2 and a high depth of discharge of 30 mAh cm-2 (DOD ≈ 54%) continued for over 700h. This work provides a novel strategy for high-performance rechargeable Zn-ion batteries.

Manipulating the Solvation Structure and Interface via a Bio-Based Green Additive for Highly Stable Zn Metal Anode.

The practical application of aqueous zinc-ion batteries (AZIBs) is limited by serious side reactions, such as the hydrogen evolution reaction and Zn dendrite growth. Here, the study proposes a novel adoption of a biodegradable electrolyte additive, γ-Valerolactone (GVL), with only 1vol.% addition (GVL-to-H2O volume ratio) to enable a stable Zn metal anode. The combination of experimental characterizations and theoretical calculations verifies that the green GVL additive can competitively engage the solvated structure of Zn2+ via replacing a H2O molecule from [Zn(H2O)6]2+, which can efficiently reduce the reactivity of water and inhibit the subsequent side reactions. Additionally, GVL molecules are preferentially adsorbed on the surface of Zn to regulate the uniform Zn deposition and suppress the Zn dendrite growth. Consequently, the Zn anode exhibits boosted stability with ultralong cycle lifespan (over 3500h) and high reversibility with 99.69% Coulombic efficiency. The Zn||MnO2 full batteries with ZnSO4-GVL electrolyte show a high capacity of 219 mAh g-1 at 0.5 A g-1 and improved capacity retention of 78% after 550 cycles. This work provides inspiration on bio-based electrolyte additives for aqueous battery chemistry and promotes the practical application of AZIBs.

Engineering a Ni-Al Brucite-Based Interface Layer with Regulated Zn2+ Flux for Highly Reversible Zn Metal Anodes.

Practical aqueous Zn-ion batteries are appealing for grid-scale energy storage with intrinsic safety and cost-effectiveness, yet their cycling stability and reversibility are limited by unwanted dendrite growth and water-induced erosions on Zn. Herein, a hydrophilic and Zn2+-conductive Ni-Al layered double hydroxide (NiAl-LDH) interphase layer is constructed on the surface of Zn, in which NiAl-LDH enables a more uniformly distributed Zn2+ concentration and interfacial electric field owing to its large internal Zn2+ channels and favorable charge redistribution effect. Consequently, the NiAl-LDH-integrated Zn anode achieves low voltage hysteresis and high reversibility of Zn plating/stripping with uniform underneath deposition behaviors. Remarkably, the resultant NiAl-2 LDH@Zn delivers superior cycling durability over 2800 h (∼4 months, 0.5 mA cm-2), realizes high reversibility with 99.4% average Coulombic efficiency over 1400 cycles, and confers stable operation of full Zn cells with high V2O5 mass loadings. This work offers a facile and instructive interface design approach for achieving highly stable Zn metal anodes.

Zinc carboxylate optimization strategy for extending Al-air battery system's lifetime

Although Al-air batteries are expected to be the candidates for energy conversion systems in renewable energy market due to the higher energy density, richer reserves, and lighter mass of Al metal, the anode self-discharge is seen as a notorious issue that seriously sacrifices battery durability and stability. Herein, we propose zinc carboxylate inhibition of anode self-discharge for enhancing Al-air battery's lifetime, where the ionized Zn2+ induces a Zn guard on Al surface, and the hydrolysate RCOOH dominates an adsorption layer on the outer surface of Zn, ensuring a double protection for metal anode by means of advanced “one stone two birds” strategy. The results show that the typical zinc carboxylates improve the absolute anticorrosion efficiency of anode greatly, especially the maximum of 92.24% after zinc malate optimization. Furthermore, battery capacity and anode efficiency are as high as 2685.20 mAh g−1 and 90.11% at 20 mA cm−2 respectively. The cyclic discharge lifetime of system (0.12 g fuel) exceeds 19.01 h, which is 1.72 times longer than traditional optimization. Finally, the optimization mechanism is revealed based on Monte Carlo simulation and density functional theory calculation, which the double CO groups in the hydrolysate of zinc malate dominates the harmonious interaction between RCOOH adsorption layer and active metals, exhibiting a high-energy efficiency and long-lifetime Al-air battery power system.

Boosting the efficiency of quantum dot–sensitized solar cells over 15% through light‐harvesting enhancement

AbstractHow to improve the capacity of light‐harvesting is still an important point and essential strategy for the assembling of high‐efficiency quantum dot–sensitized solar cells (QDSCs). A believable approach is to implant new light absorption materials into QDSCs to stimulate the charge transfer. Herein, the few‐layer black phosphorus quantum dots (BPQDs) are synthesized by electrochemical intercalation technology using bulk BP as source. Then the obtained BPQDs are deposited onto the surface of Zn–Cu–In–S–Se (ZCISSe) QD‐sensitized TiO2 substrate to serve as another light‐harvesting material for the first time. The experimental results have shown that BPQDs can not only increase the absorption intensity by photoanode but also reduce unnecessary charge recombination processes at the interface of photoanode/electrolyte. Through optimizing the size and deposition process of BPQDs, the champion power conversion efficiency of ZCISSe QDSCs is increased to 15.66% (26.88 mA/cm2, Voc = 0.816 V, fill factor [FF] = 0.714) when compared with the original value of 14.11% (Jsc = 25.41 mA/cm2, Voc = 0.779 V, FF = 0.713).

Effect of ZnAl‐LDH on corrosion resistance of Zn–55Al alloy in NaCl solution

AbstractZnAl layered double hydroxides (Zn6Al2(OH)16CO3, LDH) are the unique phase in the corrosion products of Zn–Al coating compared with the corrosion products of pure Zn coating. The effect of LDH on the corrosion resistance of Zn–55Al coating is investigated in this work. The LDH preferentially grows on the Zn‐rich region of Zn–55Al alloy, and then gradually grows on the Al‐rich region. The prepared LDH film can effectively inhibit the formation of simonkolleite (Zn5(OH)8Cl2, ZHC), hydrozincite (Zn5(CO3)2(OH)6, HZ), and ZnO in the corrosion product film of Zn–55Al alloy, making the corrosion product film more dense and less prone to cracking, which can effectively prevent the corrosion of Zn–55Al alloy. The LDH film can effectively reduce the corrosion current density and improve the electrochemical impedance of pure Zn. In the end, the corrosion protection mechanism of LDH on the surface of Zn–55Al alloy was discussed.