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Dendritic growth is a common behavior during the electrodeposition of zinc, which degrades the compactness and thickness uniformity of the zinc film. In this work, a series of quaternary ammonium compounds (QAC) with different non-polar groups (based on the number of carbon atoms in non-polar groups represented as C1, C4, C8, C12 and C16, respectively) were introduced into the basic electrolyte to inhibit the zinc dendritic growth. The results showed that the deposition of zinc became smoother with the increase of non-polar group length, which was attributed to the fact that the non-polar groups of the additive limit the random diffusion of Zn2+ and changed the adsorption state of the surface, so that a uniform zinc film was obtained. Meanwhile, the Zn-Zn symmetric cells with the addition of C8 achieved a stable cycle time of over 600 h. But with the further increase of length (C12 and C16), the migration of Zn2+ to the electrode surface became extremely difficult for strong steric hindrance, resulting in a rough deposition morphology. • The non-polar groups of the selected additives have a hindering effect on zinc ions. • Regulating the hydrocarbon chain length of the nonpolar group of the additive change the zinc film morphology. • The additive with appropriate hydrocarbon chain length obtain uniform zinc deposition. [ABSTRACT FROM AUTHOR]

Modulating the morphology of metal-organic frameworks (MOFs) has been identified as an effective strategy for enhancing the electrocatalytic performance of CO 2 reduction reactions (CO 2 RR). In this study, CAU-17 MOFs ([Bi(BTC)(H 2 O)]·2 H 2 O·MeOH) were prepared via a sonication-assisted method at room temperature, which is considered a simpler technique compared to the conventional hydrothermal method. Additionally, the morphology of CAU-17 MOFs was further regulated by incorporating a rare-earth metal (La), resulting in the observation of two distinct structures, i.e. CAU-17 hexagonal prism (CAU-17-HP) and CAU-17 layer (CAU-17-Layer). Compared to CAU-17-HP, CAU-17-Layer exhibits an excellent selectivity towards formate with the maximum Faradaic efficiency of 95.5% at − 1.1 V RHE in an H-cell. Subsequently, the limited catalytic activity of CAU-17-Layer was boosted by anchoring nano CeO 2 onto its surfaces (CeO 2 @CAU-17-Layer). The as-prepared composite catalyst demonstrated outstanding performance in the conversion of CO 2 to formate, with a current density surpassing − 100 mA cm-2 at potentials more negative than − 1.0 V RHE and reaching − 200 mA cm-2 at − 1.5 V RHE in a flow cell. This study demonstrates the significant potential of morphology-engineered and rare-earth metals composited MOFs in facilitating highly efficient reduction of CO 2. • Bismuth-based metal-organic frameworks (CAU-17 MOFs) were prepared via a sonication-assisted method at room temperature. • The morphology of CAU-17 MOFs was regulated by rare-earth metal (La). • Morphology engineering boosted the catalytic performance of CAU-17-MOFs. • When incorporating nano-CeO 2 into CAU-17-Layer, the current density reached − 200 mA cm-2 at − 1.5 V RHE. [ABSTRACT FROM AUTHOR]

A completely nickel-aluminum-copper (Ni-Al-Cu) layer was obtained through thermal diffusion process on a nickel-aluminum-bronze (NAB) substrate. The cumulative mass loss of the NAB alloy during the cavitation erosion tests was about 6.4 times and 5.5 times as large as that of the Ni-Al-Cu layer in distilled water and 3.5 wt% sodium chloride (NaCl), respectively. Electrochemical measurements under quiescence and cavitation erosion conditions were conducted to investigate the synergistic effects of cavitation erosion and corrosion. The results showed that the synergism had measurable effect on the cavitation erosion-corrosion process for both the NAB alloy and the Ni-Al-Cu layer. The total contribution of the cavitation erosion component including W E and W CIE was more than 80% and W E occupied the largest percentage. Thus, the improved cavitation erosion resistance of the Ni-Al-Cu layer was mainly due to mechanical factors, which implied a homogeneous and refined microstructure and the formation of hardened Ni 3 Al phase. [ABSTRACT FROM AUTHOR]

The preparation of copper matrix composites with high graphene content is difficult, facing the problem of graphene agglomeration. This study proposed a layer-by-layer electrodeposition method to obtain the reduced graphene oxide/copper (RGO/Cu) composite with a layered structure. It was found that the layered distribution of RGO avoided the occurrence of agglomeration effectively, which was conducive to the excellent mechanical strength and toughness of the composite. The strength of the RGO/Cu composite increased with the number of layers, and the tensile strength of the 29-layer composite was 34.2 % higher than that of pure copper. While, its elongation remained at the same level as that of pure copper. The toughening and strengthening mechanism of layered RGO in the composite was analyzed by molecular dynamics simulation. Confinement on crack propagation and strain energy consumption by sliding of layered RGO were identified as the reason for maintaining the high toughness of the composite, and stress transfer, grain refinement and dislocation strengthening were contributed to the high tensile strength. • RGO/Cu composite with a layered structure was prepared by layer-by-layer electrodeposition. • Compared with pure copper, the tensile strength of 29-layer RGO/Cu increased by 34.2 %, while the toughness remained unchanged. • The toughening and strengthening mechanism of layered RGO in the composite was analyzed by molecular dynamics. [ABSTRACT FROM AUTHOR]

ZnAlCe layered double hydroxide intercalated by molybdate (ZnAlCe MoO 4 LDH) was successfully synthesized by using co-precipitation method, and the morphology, structure of ZnAlCe MoO 4 LDH were observed and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) techniques. The inhibition behavior of ZnAlCe MoO 4 LDH for Q235 steel in 3.5%NaCl solution was determined by polarization curves, electrochemical impedance spectroscopy (EIS), inductively coupled plasma mass spectrometer (ICP-MS) and X-ray photoelectron spectrometer (XPS) methods. The results shows that the synthesized ZnAlCe MoO 4 LDH has a lamellar structure with a particle size of 0.1–2.0 μm, an average thickness of 30 nm, and a basal plane spacing of 0.898 nm. Compared with the addition of ZnAl layered double hydroxide intercalated by nitrate (ZnAl NO 3 LDH) and ZnAl layered double hydroxide intercalated by molybdate (ZnAl MoO 4 LDH) in 3.5% NaCl solution, Q235 steel in 3.5%NaCl + ZnAlCe MoO 4 LDH solution has a lower corrosion current density, larger polarization resistance and a higher inhibition efficiency. The addition of ZnAlCe MoO 4 LDH will reduce the chloride concentration in 3.5% NaCl solution by the anion exchanged with molybdate, and improve the corrosion resistance of Q235 steel owing to the formation of passive film with the composition of ferrous or iron molybdate and deposition film with zinc and cerium hydroxides. [ABSTRACT FROM AUTHOR]

Nickel alloy 690 (Ni690) were fabricated by wire arc additive manufacturing (WAAM) with three kinds of TiC particles adding contents (no TiC addition, 0.5 wt% TiC, 1.0 wt% TiC) based on cold metal transfer (CMT) technology. The effects of TiC particles adding content on the microstructure, mechanical properties and corrosion resistance were investigated. After adding 1.0 wt% TiC particles, the average length of the γ grains decreased from 301 ± 61 µm to 114 ± 15 µm and the structure of grains changed from columnar dendrite into equiaxed dendritic at the top of each layer, which is results of the heterogeneous nucleation and increase of constitutional supercooling caused by TiC particles. The difference between horizontal and vertical mechanical properties of WAAM Ni690 component disappeared because the heterogeneous nucleation caused by TiC particles prevented the epitaxial growth. The ultimate tensile strength of the WAAM 1.0TiC-Ni690 component reached 590 MPa in both directions, which increased 10 % compared with no TiC addition. The improvement of mechanical properties was owing to the grain refinement and the formation of reinforcing TiC/(Ti, Nb)C second-phase particles. The potentiodynamic polarization tests showed that the improved corrosion resistance with the increased content of TiC particles. The electrochemical impedance spectroscopy (EIS) tests results showed that due to the refined γ columnar grains providing more nucleation sites, a denser and thicker passive film was formed, which improved the corrosion resistance. The composition of the passive film was analyzed by X-ray photoelectron spectroscopy (XPS). The results reflected the more content of oxides and hydroxides of Cr in the passive film of WAAM 1.0TiC-Ni690 sample represented the denser passive film and better corrosion resistance. • Nickel alloy 690 (Ni690) were fabricated by wire arc additive manufacturing (WAAM) with different kinds of TiC particles adding contents. The TiC particles improved the mechanical properties and corrosion resistance • With the addition of TiC particles, the anisotropy in strength of WAAM Ni690 component disappeared for heterogeneous nucleation and the reinforcing TiC/(Ti, Nb)C particles improved the strength of WAAM 1.0TiC-Ni690 component in both directions reaching 590 MPa. • The refiner columnar γ grains offered more nucleation sites on the grain boundaries for the formation of thicker passive film. The more content of oxides and hydroxides of Cr in the passive film of WAAM 1.0TiC-Ni690 component represented the denser passive film and better corrosion resistance. [ABSTRACT FROM AUTHOR]

The initiation of corrosion pits in pipeline steels plays an important role in the development of stress corrosion cracking. In order to reveal the effect of inclusions on corrosion initiation sites and also to clarify contradictory results from previous literature, we proposed an ex situ characterization method that is allowed to characterize exactly the same inclusion or location of the surface of steel before and after corrosion tests. The time-dependent corrosion behaviour of the inclusions and the surrounding X100 steel matrix at the same area before and after early stage immersion in a near-neutral pH bicarbonate solution was investigated by ex situ scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis and localized electrochemical impedance spectroscopy (LEIS). The sizes of most inclusions in X100 steel are below 3 μm. The results challenge the long-held opinion of previous work that corrosion pit initiations are related with the inclusions. It has been found that most of the inclusions remain stable (intact) during the whole testing time although severe corrosion occurs on the matrix of the steel. The chemical composition of the inclusion greatly affects the chemical stability of the inclusion. SiO 2 inclusions and complex inclusions with a high SiO 2 content remain intact although obvious general corrosion occurs on the steel matrix under the investigated immersion period. Inclusions with little Si, such as Al–Mg–Ca–O enriched inclusions, totally disappear after certain immersion time. During the immersion, the corrosion product tends to deposit at the interstice between the inclusion and steel matrix. [ABSTRACT FROM AUTHOR]

Electrodeposition of metals and alloys in ionic liquids has been employed in a broader range of fields. Issues regarding the evolution of hydrogen, toxicity of reagents can be overcome by utilizing ionic liquids. This review outlines the current state of electrodeposition of various types of metals and their alloys in ionic liquids with particular focus on the work within the last decade. The metals are categorized into four groups and special attention is paid to the reactive metals that cannot possibly be deposited from traditional aqueous solutions. [ABSTRACT FROM AUTHOR]

Highlights: [•] Diffusion coating treatment for Mg alloys in Al-containing molten salts. [•] The diffusion coating process was carried at lower temperatures (280–400°C). [•] The diffusion kinetics of the formed intermetallic coatings were investigated. [•] The interdiffusion coefficients and activation energies for each phase were obtained. [ABSTRACT FROM AUTHOR]

During the 120 years' development route of the nickel-based cathode, lots of efforts have been made to realize alkaline batteries with better performance. From the earliest Edison's nickel-iron battery to the modern nickel-based battery, progress is always accompanied by backtracking steps, exhibiting a spiral-rising feature. In the early researches, composition and structures of cathodes gained most of the attention while since the 21st century, the morphology of the active materials has taken most of the research areas. Although the research interests varied with the development of technology, the core issues in material science still exist and cause unfavored problems, including insufficient energy density, limited cyclability, and inadequate rate performance. This review mainly focuses on describing a comprehensive development story of the nickel-based cathode and explaining the reasons for technology alteration. In the end, issues needed attention for future researches are presented to provide practical guidance. Image 1 [ABSTRACT FROM AUTHOR]