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Efficient and low-cost electrocatalysts for the hydrogen evolution reaction (HER) in alkaline media are essential for sustainable hydrogen production. In this study, Ni electrocatalysts were deposited on pencil graphite using a simple one-step pulsed current electrodeposition method, from both acidic Watts and alkaline citrate baths. The influence of bath type and electrodeposition parameters—current density and temperature—on catalyst morphology and performance for HER was systematically investigated by scanning electron microscopy and electrochemical methods. Linear sweep voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy (EIS) were used to evaluate the electrocatalytic activity, stability, and HER mechanism. The best catalytic performance was achieved for the Ni electrocatalyst deposited from the citrate bath at 50 mA cm−2 and 40 °C, showing an exchange current density of 0.93 mA cm−2, a Tafel slope of −208 mV dec−1, and overpotentials of −210 mV and −386 mV at 10 and 100 mA cm−2, respectively, in 1 M KOH solution. Chronopotentiometry confirmed improved stability and an overpotential reduction of approximately 92 mV as compared to pure Ni, while EIS revealed the lowest charge transfer resistance. It was shown that the electrocatalysts deposited from the citrate bath outperform those from the Watts bath, and electrodeposition at 40 °C is optimal for achieving the highest electrocatalytic activity for HER.

Electrodeposition of lithium (Li) metal is critical for high-energy batteries 1 . However, the simultaneous formation of a surface corrosion film termed the solid electrolyte interphase (SEI) 2 complicates the deposition process, which underpins our poor understanding of Li metal electrodeposition. Here we decouple these two intertwined processes by outpacing SEI formation at ultrafast deposition current densities 3 while also avoiding mass transport limitations. By using cryogenic electron microscopy 4 – 7 , we discover the intrinsic deposition morphology of metallic Li to be that of a rhombic dodecahedron, which is surprisingly independent of electrolyte chemistry or current collector substrate. In a coin cell architecture, these rhombic dodecahedra exhibit near point-contact connectivity with the current collector, which can accelerate inactive Li formation 8 . We propose a pulse-current protocol that overcomes this failure mode by leveraging Li rhombic dodecahedra as nucleation seeds, enabling the subsequent growth of dense Li that improves battery performance compared with a baseline. While Li deposition and SEI formation have always been tightly linked in past studies, our experimental approach enables new opportunities to fundamentally understand these processes decoupled from each other and bring about new insights to engineer better batteries. We report the discovery of lithium metal’s intrinsic growth morphology, a rhombic dodecahedron, and leverage these rhombic dodecahedra as nucleation seeds for improved battery performance.

The propensity of metals to form irregular and nonplanar electrodeposits at liquid-solid interfaces has emerged as a fundamental barrier to high-energy, rechargeable batteries that use metal anodes. We report an epitaxial mechanism to regulate nucleation, growth, and reversibility of metal anodes. The crystallographic, surface texturing, and electrochemical criteria for reversible epitaxial electrodeposition of metals are defined and their effectiveness demonstrated by using zinc (Zn), a safe, low-cost, and energy-dense battery anode material. Graphene, with a low lattice mismatch for Zn, is shown to be effective in driving deposition of Zn with a locked crystallographic orientation relation. The resultant epitaxial Zn anodes achieve exceptional reversibility over thousands of cycles at moderate and high rates. Reversible electrochemical epitaxy of metals provides a general pathway toward energy-dense batteries with high reversibility.

Lifetimes of Ag/AgCl electrodes determine whether it is possible to monitor the concentration of chloride ions in marine concrete structures. A novel manufacturing method, pulse current electrodeposition at a low current density, was proposed to prepare the long-lifetime Ag/AgCl electrode. Influences of electrodeposition duration were investigated on the Nernst response, exchange current density, and lifetime of Ag/AgCl electrodes, and the properties were also compared to those of the ones electrodeposited by applying constant currents. Ag/AgCl electrodes prepared with the pulse current exhibited a wider potential response, a higher exchange current density, and a longer lifetime than those prepared by the constant current under the same equivalent charge transfer conditions. AgCl film on the electrode prepared with the pulse current displayed a thicker layer, a lower density of micropores, a higher Cl/O ratio, and a lower Ag/Cl ratio than those of its counterpart electrodeposited by applying the constant current. The lifetime of the Ag/AgCl electrode was mainly determined by the thickness of AgCl films in the concrete environment. The lifetimes of the Ag/AgCl electrode, which was prepared with a 0.1 mA cm−2 pulse current for 15 h, were 420 h in pore solution and more than 3500 h in mortar, respectively. In addition, the potential of this Ag/AgCl electrode did not show any significant decrease after 3500 h in the mortar without Cl−. The results suggest that pulse current electrodeposition is an effective method to improve the lifetimes of Ag/AgCl electrodes in concrete.

Aqueous zinc batteries are appealing devices for cost-effective and environmentally sustainable energy storage. However, the zinc metal deposition at the anode strongly influences the battery cycle life and performance. To circumvent this issue, here we propose the use of lanthanum nitrate (La(NO 3 ) 3 ) as supporting salt for aqueous zinc sulfate (ZnSO 4 ) electrolyte solutions. Via physicochemical and electrochemical characterizations, we demonstrate that this peculiar electrolyte formulation weakens the electric double layer repulsive force, thus, favouring dense metallic zinc deposits and regulating the charge distribution at the zinc metal|electrolyte interface. When tested in Zn||VS 2 full coin cell configuration (with cathode mass loading of 16 mg cm −2 ), the electrolyte solution containing the lanthanum ions enables almost 1000 cycles at 1 A g −1 (after 5 activation cycles at 0.05 A g −1 ) with a stable discharge capacity of about 90 mAh g −1 and an average cell discharge voltage of ∼0.54 V. Zinc metal is a promising anode material for aqueous secondary batteries. However, the unfavourable morphologies formed on the electrode surface during cycling limit its application. Here, the authors report the tailoring of the surface morphology using a lanthanum nitrate aqueous electrolyte additive.

The corrosion resistance of nickel–titanium nitride (Ni/TiN) composites is significantly influenced by the operation parameters during the jet pulse electrodeposition (JPE) process. The effect of current density, jet rate, TiN concentration, and duty cycle impact on the anti-corrosion property of Ni/TiN composites were investigated and optimized using the response surface method (RSM). After the optimization of the operation parameters, the corrosion current of Ni/TiN composites decreased from 9.52 × 10−5 A/cm2 to 4.63 × 10−5 A/cm2. The corrosion current of Ni/TiN composites decreased initially and then increased with an increase in current density, jet rate, TiN concentration, and duty cycle. During the jet electrodeposition process, the influence of the duty cycle on the corrosion current of Ni/TiN composites was comparatively insignificant, whereas the concentration of TiN had a significant effect on the corrosion current. The error rate between the predicted value and the measured result from the corrosion current of Ni/TiN composites was only 0.64%, indicating the high accuracy of fitting the model. Furthermore, X-ray diffraction (XRD) patterns and scanning electron microscope (SEM) images revealed that the optimized Ni/TiN composites comprised significant Ti content, fine nickel gain, and a compact, smooth structure. In addition, the electrochemical measured results demonstrated that the optimized Ni/TiN composites possessed a low self-corrosion current and high self-corrosion potential. These findings show that the optimized composites have a substantially greater corrosion resistance compared to two other unoptimized Ni/TiN composites.

Performing CO 2 reduction in acidic conditions enables high single-pass CO 2 conversion efficiency. However, a faster kinetics of the hydrogen evolution reaction compared to CO 2  reduction limits the selectivity toward multicarbon products. Prior studies have shown that adsorbed hydroxide on the Cu surface promotes CO 2  reduction in neutral and alkaline conditions. We posited that limited adsorbed hydroxide species in acidic CO 2 reduction could contribute to a low selectivity to multicarbon products. Here we report an electrodeposited Cu catalyst that suppresses hydrogen formation and promotes selective CO 2 reduction in acidic conditions. Using in situ time-resolved Raman spectroscopy, we show that a high concentration of CO and OH on the catalyst surface promotes C-C coupling, a finding that we correlate with evidence of increased CO residence time. The optimized electrodeposited Cu catalyst achieves a 60% faradaic efficiency for ethylene and 90% for multicarbon products. When deployed in a slim flow cell, the catalyst attains a 20% energy efficiency to ethylene, and 30% to multicarbon products. Performing CO 2 reduction in acidic conditions enables high CO 2 utilization. Here, the authors report an electrodeposited Cu catalyst which achieves a 60% faradaic efficiency for ethylene and 90% for multicarbon products–both records for acidic CO 2 reduction.

Lithium metal has gravimetric capacity ∼10× that of graphite which incentivizes rechargeable Li metal batteries (RLMB) development. A key factor that limits practical use of RLMB is morphological instability of Li metal anode upon electrodeposition, reflected by the uncontrolled area growth of solid–electrolyte interphase that traps cyclable Li, quantified by the Coulombic inefficiency (CI). Here we show that CI decreases approximately exponentially with increasing donatable fluorine concentration of the electrolyte. By using up to 7 m of Li bis(fluorosulfonyl)imide in fluoroethylene carbonate, where both the solvent and the salt donate F, we can significantly suppress anode porosity and improve the Coulombic efficiency to 99.64%. The electrolyte demonstrates excellent compatibility with 5-V LiNi0.5Mn1.5O₄ cathode and Al current collector beyond 5 V. As a result, an RLMB full cell with only 1.4× excess lithium as the anode was demonstrated to cycle above 130 times, at industrially significant loading of 1.83 mAh/cm² and 0.36 C. This is attributed to the formation of a protective LiF nanolayer, which has a wide bandgap, high surface energy, and small Burgers vector, making it ductile at room temperature and less likely to rupture in electrodeposition.

Thin films of Cu 2 CoSnS 4 (CCTS) are electrodeposited onto fluorine tin oxide substrate using pulsed electrodeposition mode for various time periods followed by sulfurization treatment at 500 °C. The pulse potential (V1) is held constant at 0 V vs. Ag/AgCl, while (V2) is set at − 1.1 V vs. Ag/AgCl. The effect of pulse duration on the CCTS proprietress is being investigated. Cyclic voltammetry was used to study the electrochemical behaviors of Cu–Co–Sn–S precursors, while in situ electrochemical impedance spectroscopy investigated the electrical properties of the system during electrodeposition of CCTS at − 1.10 V. The impedance spectra revealed a capacitive loop pattern along with Warburg diffusion. The samples were analyzed by X-ray diffraction (XRD), Raman spectroscopy, and UV–visible spectroscopy. Both XRD data and Raman spectra indicated that the CCTS thin films have a stannite structure. The films deposited for 20 min and 30 min exhibit a predominantly pure CCTS phase. Moreover, deposition for 20 min exhibits a homogeneous morphology with a nearly stoichiometric composition along with an optical band gap energy of 1.54 eV. Apart from the CCTS phase, noticeable secondary phases are present in films deposited at both low and high pulse durations, and they have been observed to slightly affect the gap energy. Graphical abstract

The entire manufacturing chain of the chip, the surface engineering technology represented by electrochemical deposition technology, plays a very important role in supporting it. This paper delves into the impact of brightener (SPS) concentration on the copper electroplating behavior within the electroplating solution, employing electrochemical testing methods. Following this analysis, copper electroplating experiments are conducted to obtain the electroplated layers. Ultimately, the study examines the influence of brightener concentration on the surface morphology of these copper electroplating layers using surface profilometry and X-ray diffraction (XRD) analysis. The experimental findings reveal that an increase in the concentration of the brightener (SPS) leads to an enhancement in the brightness of the plated surface.