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This paper describes the simple and label-free detection of thrombin using optical fiber surface plasmon resonance (SPR) sensors based on gold films prepared by the cost-effective method of electroless plating. The plating conditions for simultaneously obtaining gold film on cylindrical core and end surfaces of an optical fiber suitable for measurement were optimized. The fabricated sensor exhibited a linear refractive index sensitivity of 2150 nm/RIU and 7.136 (a.u.)/RIU in the refractive index of 1.3329–1.3605 interrogated by resonance wavelength and amplitude methods respectively and a single wavelength monitoring method was proposed to investigate the sensing performance of this sensor. Polyadenine diblock and thiolated thrombin aptamers were immobilized on gold nanoparticles and gold films respectively to implement a sandwich optical fiber assay for thrombin. The developed optical fiber SPR sensors were successfully used in the determination of thrombin down to 0.56 nM over a wide range from 2 to 100 nM and showed good selectivity for thrombin, which indicated their potential clinical applications for biomedical samples. [ABSTRACT FROM AUTHOR]

The ultraprecision machining of the mold surface is important because the performance of optical components produced using optical injection is related to the surface roughness and shape precision of the mold core. To process hard-to-cut mold core materials such as stainless steel, electroless nickel-phosphorus (NiP) plating is applied to the surface of the substrate, and ultraprecision processing is performed on the plating surface using diamond turning (DT) and magnetorheological finishing (MRF). Although MRF processing can remove tool marks caused by diamond turning and improve shape accuracy, it suffers from poor processability for NiP. In this paper, an ultraprecision processing method with a heat treatment process was presented to improve the MRF processability of electroless NiP. The plating was heat-treated under each condition and subjected to DT processing followed by MRF. The surface roughness and reflectance were measured and evaluated after processing. As a result, the surface roughness of NiP subjected to a 1-h heat treatment at 450 °C significantly decreased from Ra 7.0 nm to Ra 1.5 nm when compared to the specimen that did not undergo any heat treatment. An improvement in surface roughness confirmed that reflectance improved by more than 9% and 18%, respectively, compared to that for the diamond-turned and non-heat-treated specimen. These results confirmed that the MRF performance was improved through the NiP heat treatment process and contributed to quality improvements in ultraprecision injection optical parts. Furthermore, this technology can be applicable to various fields that used NiP plating, including the manufacturing of metal reflectors in the visible and ultraviolet regions. [ABSTRACT FROM AUTHOR]

The development of Li-ion battery cases requires superior electrical conductivity, strength, and corrosion resistance for both cathode and anode to enhance safety and performance. Among the various battery case materials, super duplex stainless steel (SDSS), which is composed of austenite and ferrite as two-phase stainless steel, exhibits outstanding strength and corrosion resistance. However, stainless steel, which is an iron-based material, tends to have lower electrical conductivity. Nevertheless, nickel-plating SDSS can achieve excellent electrical conductivity, making it suitable for Li-ion battery cases. Therefore, this study analysed the plating behaviour of SDSS plates after nickel plating to leverage their exceptional strength and corrosion resistance. Electroless Ni plating was performed to analyse the plating behaviour, and the plating behaviour was studied with reference to different plating durations. Heat treatment was conducted at 1000 °C for one hour, followed by cooling at 50 °C/s. Post-heat treatment, the analysis of phases was executed using FE-SEM, EDS, and EPMA. Electroless Ni plating was performed at 60–300 s. The plating duration after the heat treatment was up to 300 s, and the behaviour of the materials was observed using FE-SEM. The phase analysis concerning different plating durations was conducted using XRD. Post-heat treatment, the precipitated secondary phases in SAF2507 were identified as Sigma, Chi, and CrN, approximating a 13% distribution. During the electroless Ni plating, the secondary phase exhibited a plating rate equivalent to that of ferrite, entirely plating at around 180 s. Further increments in plating time displayed growth of the plating layer from the austenite direction towards the ferrite, accompanied by a reduced influence from the substrate. Despite the differences in composition, both the secondary phase and austenite demonstrated comparable plating rates, showing that electroless Ni plating on SDSS was primarily influenced by the substrate, a finding which was primarily confirmed through phase analysis. [ABSTRACT FROM AUTHOR]

In this work, a simple and cost-effective method was proposed and developed to prepare a novel multilayer-structured Kevlar®@nickel-phosphorus-boron@copper@copper stearate (Kevlar®@Ni–P–B@Cu@CS) composite fabric with high conductivity, high flexibility, high hydrophobicity, and high durability to effectively shield electromagnetic interference (EMI). In this method, an amorphous Ni–P–B alloy nanolayer was initially deposited onto a Kevlar® fabric via electroless plating. Afterward, a crystalline Cu nanolayer was deposited as the second layer via electroplating. Finally, a monolayer of copper stearate was innovatively self-assembled as the outermost protective layer. The Cu deposition was effectively adjusted and designed by controlling the plating current and plating time. The electrical resistance and contact angle of the optimized Kevlar®@Ni–P–B@Cu@CS composite fabric were as low as 3.2 mΩ sq−1 and as high as 115.39°, respectively, indicating that the fabric could withstand bending, tape-off, corrosion, and accelerated environmental tests. The average EMI-shielding efficiency of the durable composite fabric was 93.9 dB in the frequency range of 8.2–12.4 GHz, which was mainly attributed to the absorption loss. Thus, the proposed material configuration has promise for applications in aviation, aerospace, telecommunication, wearable devices, and military industries. [ABSTRACT FROM AUTHOR]

This study reports novel, compact, and additively manufactured quadrupole mass filters (QMFs) with adequate filtering performance for practical mass spectrometry applications. The QMFs are monolithically fabricated via vat photopolymerization of glass‐ceramic resin using 57 µm × 57 µm × 100 µm voxels, and selective electroless plating of nickel‐boron. Experimental characterization of QMF prototypes at 1.74 MHz using FC‐43 yields 131 Da peaks with 0.50 Da full width at half maximum (260 resolution), surpassing the resolution of reported miniaturized counterparts under similar conditions, and being on par with commercial, non‐miniaturized, heavier devices. The sensitivity of the 3D‐printed devices is estimated at 0.13 mA Torr−1 (comparable to that of optimized, commercial counterparts), while the devices attained up to 250 Da of mass range (limited by the driving electronics). The work is of interest to low‐cost, capable mass spectrometry, 3D‐printed instruments, and in‐space manufacturing of complex instrumentation. [ABSTRACT FROM AUTHOR]

Among the various reinforcement phases available in Cu-based composites, the unique layered structure and easy diffusion of A-layer atoms make MAX phases more suitable for reinforcing a copper matrix than others. In this study, Cu-coated Ti3AlC2 particles (Cu@Ti3AlC2) were prepared through electroless plating, and Cu@Ti3AlC2/Cu composites were fabricated via vacuum hot-press sintering. The phase composition and microstructure of both Cu@Ti3AlC2 powder and composites were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results demonstrate the creation of successful electroless copper plating to obtain a Cu coating on Ti3AlC2 particles. At 850 °C, a small amount of Ti3AlC2 particles decompose to form TiCx, while Al atoms from the A layer of MAX phase diffuse into the Cu matrix to form a solid solution with Cu(Al). The test results reveal that the density of the Cu@Ti3AlC2/Cu composite reaches 98.5%, with a maximum compressive strength of 705 MPa, which is 8.29% higher than that of the Ti3AlC2/Cu composite. Additionally, the compressive strain reaches 37.6%, representing an increase of 12.24% compared to that exhibited by the Ti3AlC2/Cu composite. [ABSTRACT FROM AUTHOR]

In this study, sub-microscale spherical particles composed of SiO2 cores encapsulated by silver layers (i.e., SiO2@Ag) were synthesized and incorporated in microscale Ag-flake-filled electrically conductive adhesive (ECA). SiO2 spheres with an average diameter of 400 nm were fabricated by the modified Stöber process and then coated with a thin silver layer as a shell with a thickness of about 50 nm through electroless plating. The mechanical and electrical properties and the microstructural characteristics of the ECA filled with different ratios of SiO2@Ag spheres to Ag flakes were studied. The influence of mixed fillers with different constituents on the electrical properties of the ECA was also investigated by finite element simulation. The results show that replacing a small quantity of Ag flakes with the same mass fraction of SiO2@Ag spheres can significantly improve the electrical and mechanical properties of the ECA. The addition of SiO2@Ag spheres results in a combined effect of decreasing the space between Ag flakes and enhancing their nondirectional arrangement, leading to the formation of more conductive paths. The most obvious improvement in electrical and mechanical properties was found for ECA containing 65 wt.% conductive fillers with a weight ratio of 2:48 between SiO2@Ag spheres and Ag flakes. The simulation results show good consistency with experimental studies and demonstrate the superior enhancement effect of SiO2@Ag spheres on the overall performance of the ECA. [ABSTRACT FROM AUTHOR]

With increasing demand for Li-ion batteries, studies are focusing on enhancing battery performance and safety. However, studies on battery cases remain scarce. Herein, we propose the use of super duplex stainless steel SAF2507, which is a two-phase (austenite + ferrite) steel, for battery casings. Unlike conventional AISI304, SAF2507 maintains its corrosion resistance and strength at high temperatures and precipitates a secondary phase at approximately 975 °C. However, the effects of Ni plating on this secondary phase are not well documented. Therefore, the electroless Ni plating of SAF2507 after secondary-phase precipitation was studied. Briefly, heat treatment at 1000 °C was used to induce precipitation, and the electroless Ni plating behaviour over varying plating periods was analysed using open-circuit potential, potentiodynamic polarisation, and electrochemical impedance spectroscopy measurements. The plating state and corrosion behaviour were examined using scanning electron microscopy. Heat-treated SAF2507 steel with a secondary phase exhibited excellent electroless Ni plating behaviour, which enhances the safety and durability of Li-ion batteries. Furthermore, uniform plating and electrochemical behaviour were achieved after 180 s, suggesting that SAF2507 is superior to AISI304. These findings contribute to the development of safer and more efficient batteries and address the growing demand for Li-ion battery case materials. [ABSTRACT FROM AUTHOR]

The topic of this work was the investigation of an alternative brassing technique consisting of electroless zinc plating of a copper object in a strongly alkaline solution and subsequent annealing to achieve a characteristic brass appearance. Within the scope of the work was the determination of the mechanism of zinc deposition on the copper surface, the optimisation of the NaOH concentration (30 and 40 wt. %), time of deposition (5-120 min), as well as temperature (150 and 200 °C) and annealing time (15 – 60 min). Electrochemical methods (potentiodynamic curves and open-circuit potential), metallography, X-ray diffraction (XRD), and glow-discharge optical emission spectroscopy (GD-OES) were used to study the brassing mechanism. Electrochemical measurements have shown that zinc powder significantly decreases the surface potential of copper to the value of zinc itself and also acts as a reducing agent. The diffusion of zinc in copper was found to occur during the primary deposition of zinc with the formation of the γ phase (Cu5Zn8). The optimal NaOH concentration is 40 wt.% and the deposition time is 60 min. The optimal conditions of annealing are 200 °C and 60 min. The primary γ phase is transformed during the annealing process into β and α phases. [ABSTRACT FROM AUTHOR]

In this study, 6061-T6 aluminum alloys were plated with electroless Ni–P with different phosphorus content and three-point bending and rotating bending fatigue tests. The effects of hydrogen due to plating on mechanical properties were investigated. It was shown that the ductility decreased immediately after low-phosphorus type and high-phosphorus type Ni–P plating by three-point bending test because a hydrogen was introduced into the alloys. The fatigue strength of the low-phosphorus type Ni–P plated specimen was higher than that of the un-treated specimen, while that of the high-phosphorus type plated specimen was much lower. It is clear that the fatigue strength differs greatly depending on the phosphorus content in the plating film. 6061-T6 aluminum alloy have been reported to exhibit no hydrogen embrittlement in low strain rate tensile tests under wet condition. However, it was found that hydrogen embrittlement occurred when 6061-T6 aluminum alloy was plated with the high-phosphorus type electroless Ni–P and fatigue-tested on rotating bending machine. [ABSTRACT FROM AUTHOR]

In the processing technology of printed circuit boards, the common electroless copper plating technology of ethylenediaminetetraacetic acid disodium (EDTA-2Na) has the problems of large surface stress, uneven crystal particles, and large surface roughness of the copper plating layer. To remedy the above shortcomings and meet the current requirements for copper interconnects in printed circuit boards (PCBs), the present study has investigated a chemical copper plating system that combines a high deposition rate with low stress. An electroless copper plating was then performed on a polyacrylonitrile-butadiene-styrene (ABS) plastic resin plate with 2,6-diaminopyridine (2,6-DAP), 2,2-bipyridine, sodium hydroxyethyl sulfonate (SHES) and NiSO4·6H2O as supplementary additives. By using scanning electron microscopy (SEM), electrochemical, atomic force microscopy (AFM), and X-ray diffraction (XRD) analyses, it has been shown that the average surface roughness Ra became reduced from 202 nm to 76.1 nm when using additives in the chemical copper plating process. Also, the internal stresses of the deposited copper layer on the (220) and (311) planes of a crystalline copper layer decreased from − 70.48 and − 53.03 to − 27.31 and − 27.16 MPa, respectively. The composite additive improved the quality of the copper layer of the EDTA-2Na-based chemical copper plating system, increasing the practical range of industrial applications and facilitating the subsequent application of higher-precision processing. [ABSTRACT FROM AUTHOR]

Pd membrane on porous Al 2 O 3 , an important composite membrane for H 2 separation, is typically fabricated by electroless plating, and thus the quality of the Pd membrane is critically dependent on the seeding process. Here, a facile ultrasonication-assisted sensitization-activation process is used to load catalytic particles on porous Al 2 O 3 , subsequently followed by electroless plating of 5-μm-thick Pd membranes for H 2 separation. Uniformly distributed catalytic particles with even sizes are loaded onto Al 2 O 3 only under an optimal power of the ultrasonic agitation, then catalyzing electroless Pd membranes with a better surface topography and less defective microstructure. The optimal Pd membrane achieves a sound hydrogen flux of 0.157 mol m−2 s−1 and high H 2 /N 2 selectivity of 1835 under 723 K and 105 kPa pressure difference. Moreover, this particular Pd/Al 2 O 3 exhibits high stability in (a) Pd membrane microstructures and (b) H 2 /N 2 permeating fluxes without elemental interfacial diffusion even under long-term (156 h) at a high temperature (723 K). [Display omitted] • Ultrasonic- and magnetic-agitations are used to load Pd(Sn) seeds on porous Al 2 O 3. • High-quality electroless Pd membrane is obtained on the ultrasonically-seeded Al 2 O 3. • Mechanisms of defect-related N 2 /H 2 permeation for Pd-coated Al 2 O 3 are studied. • Ultrasonically-seeded Pd membranes exhibit high selectivity and long-term durability. • The long-term durability is related to sturdiness of Pd membrane and Al 2 O 3 support. [ABSTRACT FROM AUTHOR]

Platinum group metals (PGMs) are primarily used in automotive exhaust catalysts (autocatalysits). Spent autocatalysts are the most important secondary resource for PGMs. However, transporting autocatalyst scraps and recovering PGMs from the scraps are costly and time-consuming, owing to the low PGM content in spent autocatalysts. Thus, an effective PGM-concentration technology for the pretreatment of scrap prior to transport is required. This study develops a new pretreatment technique that is applied prior to the flotation concentration of PGMs in autocatalysts. This method utilizes electroless Cu plating followed by sulfurization. In the electroless Cu-plating process, which uses glyoxylic acid as a reducing agent, Cu is deposited on the PGM particles in the washcoat of the autocatalyst. During the sulfurization process, S vapor sulfurizes the deposited Cu into copper sulfide, which is hydrophobic. Prior to the experiments, thermodynamic considerations were made to predict the reactivity of Cu and the representative elements constituting the autocatalyst with S vapor, and the sulfurization conditions were designed. Sulfurization experiments were performed at 850 K (577 °C) in the presence of carbon (C), and the results show the successful conversion of only Cu to copper sulfide without sulfurizing the representative oxides (MgO, Al2O3, SiO2, CeO2, and ZrO2) present in the autocatalyst. Finally, in the flotation process, the copper sulfide-coated PGMs are separated from the ceramic components of the autocatalyst, which is hydrophilic; thus, it is concentrated in the froth. Flotation experiments utilizing a microbubble flotation method were successfully performed to recover the PGM concentrates. This innovative pretreatment technique is expected to reduce the cost and time required for the entire PGM recycling process. [ABSTRACT FROM AUTHOR]

Self-assembled monolayers (SAMs) with short organic chains terminated with specific functional groups are attractive for modifying surface properties for a variety of applications, including being a copper diffusion barrier layer on Si wafer. However, SAM formation is process-sensitive and ideal SAM is difficult to obtain, both of which need to carefully deal with before practical use. Herein we developed a system to achieve seamless electroless deposited copper (ELD Cu) film on an amino-terminated silane SAM modified Si wafer with the help of a bifunctional polyvinyl alcohol-capped Pd nanocluster (PVA-Pd) catalyst. The PVA-Pd acts as a catalyst for ELD Cu as well as a healing agent to fix defects of the amino silane SAM. The sheet resistance, cross-sectional morphology analysis and adhesion of ELD Cu on the Si wafer are extensively studied. By controlling the abundancy of PVA in PVA-Pd, the diffusion barrier property of a flawed amino-terminated silane SAM remains reliably effective even after a 500 °C rapid thermal annealing (RTA), evidencing the superior healing function of PVA. The whole thickness of the PVA-Pd/amino-terminated silane SAM before and after RTA is 〜6 nm and 〜2 nm, respectively, which is applicable for advanced microelectronic manufacturing.

To enhance the rock-crushing efficiency and drilling life of impregnated diamond drill bits，a strategy was proposed for the localized heterogenization of the drill bit matrix through composite electroplating reinforcement of diamond particles，separating the protrusion effect of diamonds in the drill bit matrix from their encapsulation strength.Diamond particles were strengthened by electroless plating and composite electroplating.Subsequently，the diamond drill head body was prepared through hot pressing sintering.Studies were conducted on the performance changes of the composite electroplating strengthened diamond particles，the friction and wear characteristics of the drill head body，and the protrusion state and binding interface of the diamonds within the drill head body.Results showed that a modified metal coating was obtained on the surface of diamond particles strengthened by composite electroplating.The morphology of the coating was dense and uniform，with good bonding with diamond.The composite electroplating strengthened diamond particles effectively improved the surface wettability and impact resistance of diamond.The heterogeneous matrix structure ensured the slow protrusion process and the protrusion height of the diamond.The composite electroplating strengthened diamond particles effectively improved the comprehensive performance of the diamond bit.

The effects of process parameters on the electroless plating of ionic polymer–metal composites (IPMCs) were studied in this work. Specifically, the NaBH4 reduction of platinum onto Nafion-117 was characterised. The effects of the concurrent variation of NaBH4 concentration, stir time and temperature on surface resistance were studied through a full factorial design. The three-factor three-level factorial design resulted in 27 runs. Surface resistance was measured using a four-point probe. A regression model with an R2 value of 97.45% was obtained. Surface resistance was found to decrease with increasing stir time (20 to 60 min) and temperature (20 to 60 °C). These responses were attributed to increased platinisation rates, resulting in more uniform electrode deposition, confirmed by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDAX) analysis. Surface resistance decreased, going from 1% to 5% NaBH4 concentration, but increased from 5% to 10% concentration. This behaviour was attributed to surface morphology: increased grain size inducing porous electrodes, in line with findings in the literature. The maximum tip displacement, measured through a computer vision system, as well as the maximum blocking force, measured through an analytical balance setup, were obtained for all 27 samples. The varying results were discussed with regards to surface and cross-sectional SEMs, alongside EDAX analysis.

The production of high-purity hydrogen from hydrogen storage materials with further direct use of generated hydrogen in fuel cells is still a relevant research field. For this purpose, nickel-molybdenum-plated copper catalysts (NiMo/Cu), comprising between 1 and 20 wt.% molybdenum, as catalytic materials for hydrogen generation, were prepared using a low-cost, straightforward electroless metal deposition method by using citrate plating baths containing Ni2+–Mo6+ ions as a metal source and morpholine borane as a reducing agent. The catalytic activity of the prepared NiMo/Cu catalysts toward alkaline sodium borohydride (NaBH4) hydrolysis increased with the increase in the content of molybdenum present in the catalysts. The hydrogen generation rate of 6.48 L min−1 gcat−1 was achieved by employing NiMo/Cu comprising 20 wt.% at a temperature of 343 K and a calculated activation energy of 60.49 kJ mol−1 with remarkable stability, retaining 94% of its initial catalytic activity for NaBH4 hydrolysis following the completion of the fifth cycle. The synergetic effect between nickel and molybdenum, in addition to the formation of solid-state solutions between metals, promoted the hydrogen generation reaction.

This work looks at the effects of a varying concentration, soak time, pH and temperature on the sorption of tetraammineplatinum(II) chloride (Pt-Ammine) in Nafion-117 films in the context of the electroless plating of ionic polymer–metal composites (IPMCs). Sorption is characterised by atomic absorption spectroscopy. A definitive screening design carried out determined all four factors to be significant for further analysis using response surface modelling. A duplicated central composite design (CCD) was utilised to characterise how the four factors affect the sorption amount and efficiency. Regression models for both responses were of poor fit. Nevertheless, key insights were obtained on the effects of the process parameters on sorption behaviour. The results indicate that above 0.5 g/L Pt-Ammine sorption, the platinisation of 10 × 50 mm IPMC samples through sodium borohydride reduction becomes redundant by the surface resistance metric. IPMCs with surface resistance values of approximately 2.5 Ω/square were obtained through only one round of chemical reduction. Varying surface morphologies and electrode thicknesses were analysed under a scanning electron microscope. The CCD parameter settings were validated. Recommended settings for optimised Pt-Ammine sorption in 10 × 50 mm Nafion-117 films were identified as follows: 1.0 g/L Pt-Ammine concentration, 24 h soak time, pH of 3 and temperature of 20 °C.

In this study, we have reported a new strategy to prepare metal/ceramic membranes that can be used as an alternative to conventional high-cost palladium membranes. For the first time, a uniform Ni layer was deposited using the organic-inorganic activation method via the ELP technique. Although, alloying Pd–Ni resulted in a defect-free thin membrane layer (2 μm). The H 2 permeation flux of the composite membrane was 1.43 × 10−2 mol m−2 s−1 at 450 °C and TMP of 100 kPa with infinite H 2 /N 2 selectivity. Stage cut effect as a function of transmembrane pressure (TMP) was assessed in binary mixtures at 450 °C. The prepared composite membrane indicated perfect long-time permeance stability for 145 h at 450 °C and TMP of 100–300 kPa. The results showed that solution-diffusion is the dominant mechanism in the hydrogen transport through the composite membranes. [Display omitted] • A uniform Ni layer was deposited using the organic-inorganic activation method. • Knudsen diffusion governed hydrogen transport in the Ni composite membrane. • Alloying Pd–Ni results in a defect-free membrane layer with infinite H 2 /N 2 selectivity. • The Pd–Ni composite membrane showed perfect permeance stability over 145 h at 450 °C. • Solution-diffusion governed hydrogen transport in the Pd–Ni composite membrane. [ABSTRACT FROM AUTHOR]

Hydrogen evolution through the catalytic hydrolysis of NaBH 4 by transition metals holds great promise for sustainable green energy production. In this study, we presented an electroless process for synthesizing Cr-doped Ni–B catalysts supported on rice husks. The kinetics and thermodynamics of the NaBH 4 hydrolysis were systematically investigated. The crystallography confirmed the formation of Ni and Cr connected to B. 0.8 wt% Cr also significantly impacted the Ni–B activity and enhanced the hydrogen generation rate from 394 to 801 ml min−1.g−1 at 32 °C. Based on Kinetics, NaBH 4 hydrolysis by Ni–B–Cr 0.8 needs an activation energy of 50.64 kJ mol−1 and follows zero- and first-order kinetics concerning NaBH 4 and catalyst weight. After five cycles reusability, the Ni–B–Cr 0.8 revealed excellent stability and kept its activity almost constant in basic NaBH 4 solution. [Display omitted] • Cr-doped Ni–B catalyst supported on rice husk were synthesized by electroless method. • The catalytic activity was assessed for H 2 evolution by basic NaBH 4 hydrolysis. • 0.8 wt% Cr doubled the surface area of Ni–B and raised HGR from 394 to 801 ml min.gr−1. • NaBH 4 hydrolysis by Ni–B–Cr 0.8 was first-order kinetics based on catalyst weight. • ΔH# and ΔG# of NaBH 4 hydrolysis reaction were 47.98 and 92.65 kJ mol−1. [ABSTRACT FROM AUTHOR]

The large-scale development of flexible electrode is urgently needed for water electrosplitting. Herein, the common and low-cost filter paper (FP) is utilized as the substrate to adjust the flexible property of the catalytic electrode. Through an electroless plating method, the NiFeP alloys were deposited onto the filter paper, which acted as the flexible and self-supported electrode for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The resultant NiFeP@FPs require low overpotentials of 158 mV for HER and 282 mV for OER to deliver a current density of 10 mA cm−2, and exhibit a good stability of 30 h in 1 M KOH. The synergistic effect of Fe–Ni sites regulates electron structure and boosts the catalytic activity. Benefited from good hydrophilicity and interlaced fiber structure of filter paper, electrolyte penetration and electron transfer in the sample are promoted. The assembled two-electrode electrolyzer only requires 1.814 V to achieve 100 mA cm−2 for overall water splitting and shows excellent stability. This work provides a new strategy for the development of flexible and efficient electrodes for water splitting, which advances the development of wearable electronic devices. [Display omitted] • The flexible filter paper-based electrode was successfully synthesized. • The good hydrophilicity and porous structure facilitated electrolyte permeation. • The sample required low overpotentials of 158 mV for HER and 282 mV for OER. • The two-electrode electrolyzer provided 100 mA cm−2 at a low voltage of 1.814 V. [ABSTRACT FROM AUTHOR]

Dense metallic membranes, especially Pd and Pd alloys, have been intensely investigated to provide an alternative and economical way to obtain H2 with ultrahigh purity. To overcome the high cost of Pd, composite membrane structures that comprise a thin layer of Pd are utilized. However, it is a challenge to obtain a thin, dense, and uniform Pd layer on the support materials. This study investigates the parametric analysis of γ-Al2O3 interlayer formation and the electroless Pd plating (Pd ELP) procedures on α-Al2O3 supports with the aim to achieve a thin, uniform Pd surface without annealing. Adjustments in PEG/PVA concentration, dipping time, and heat treatment enabled creating a thin γ-Al2O3 interlayer on α-Al2O3, minimizing pore size and density. Hydrazine concentration, heat treatment, and bath temperature were adjusted to optimize Pd ELP to achieve maximum yield from the plating bath and a dense, uniform surface without annealing. Pd/γ-Al2O3/α-Al2O3 structures were analyzed using scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis to observe the impact of varied parameters on surface structures. Optimized sample was compared to an annealed Pd/α-Al2O3 prepared in accordance with literature methods and a Pd/graphite/α-Al2O3 sample to validate the use of optimized ELP procedure and the γ-Al2O3 interlayer. Results show that a dense and uniform 13 μm Pd coating was achieved on a γ-Al2O3-coated α-Al2O3 support without annealing, using three fresh ELP baths. This was done using sequential hydrazine addition with a decreased concentration (1 M) into the ELP baths at 30 °C, and applying heat treatment at 120 °C between each fresh ELP bath. [ABSTRACT FROM AUTHOR]

With the prosperity of laser powder bed fusion (LPBF) technology, post-processing tends to be increasingly attractive in further improving the performance of the LPBFed parts. In this study, post-heat treatment and electroless plating were performed on the LPBFed 316L stainless steel to investigate the evolution of surface topography, mechanical property and corrosion behaviour. The results show that the as-built part features melt tracks and fine cellular substructures, which presents higher deformation resistance than the cast and recrystallized counterparts. The uniform amorphous Ni-P coating can significantly increase microhardness of as-built 316L stainless steel from ~300 to ~800 HV. In addition, the as-built parts with/without coatings have better corrosion resistance than the corresponding cast ones, which can be further improved through 450°C annealing. Moreover, the coatings can also prevent the localised corrosion effectively. Therefore, this study provides available post-processing methods for further improve the performance of LPBFed 316L stainless steel. [ABSTRACT FROM AUTHOR]

In this work, bilayer nanocoatings were designed and constructed on high-performance aromatic polysulfonamide (PSA) fibers for robust electric conduction and electromagnetic interference (EMI) shielding. More specifically, PSA fibers were first endowed with necessary electric conductivity via electroless nickel (Ni) or nickel alloy (Ni-P-B) plating. Afterward, silver electroplating was carried out to further improve the performance of the composite. The morphology, microstructure, environmental stability, mechanical properties, and EMI shielding performance of the proposed cladded fibers were thoroughly investigated to examine the effects of electrodeposition on both amorphous Ni-P-B and crystalline Ni substrates. The acquired results demonstrated that both PSA@Ni@Ag and PSA@Ni-P-B@Ag composite fibers had high environment stability, good tensile strength, low electric resistance, and outstanding EMI shielding efficiency. This indicates that they can have wide application prospects in aviation, aerospace, telecommunications, and military industries. Furthermore, the PSA@Ni-P-B@Ag fiber configuration seemed more reasonable because it exhibited smoother and denser silver surfaces as well as stronger interfacial binding, leading to lower resistance (185 mΩ cm−1) and better shielding efficiency (82.48 dB in the X-band). [ABSTRACT FROM AUTHOR]

H2 production via membrane-assisted steam methane reforming (MA-SMR) can ensure higher energy efficiency and lower emissions compared to conventional reforming processes (SMR). Ceramic-supported Pd–Ag membranes have been extensively investigated for membrane-assisted steam methane reforming applications, with outstanding performance. However, costs, sealings for integration in the reactor structure, and resistance to solicitations remain challenging issues. In this work, the surface quality of a low-cost, porous Hastelloy-X filter is improved by asymmetric filling with α-Al2O3 of decreasing size and deposition of γ-Al2O3 as an interdiffusion barrier. On the modified support, a thin Pd–Ag layer was deposited via electroless plating (ELP), resulting in a membrane with H2/N2 selectivity >10,000. The permeation characteristics of the membrane were studied, followed by testing for membrane-assisted methane steam reforming. The results showed the ability of the membrane reactor to overcome thermodynamic conversion of the conventional process for all explored operating conditions, as well as ensuring 99.3% H2 purity in the permeate stream at 500 °C and 4 bar. [ABSTRACT FROM AUTHOR]

Lattice structures are a group of cellular materials composed of regular repeating unit cells. Due to their extraordinary mechanical properties, such as specific mechanical strength, ultra-low density, negative Poisson's ratio, etc., lattice structures have been widely applied in the fields of aviation and aerospace, medical devices, architecture, and automobiles. Hybrid additive manufacturing (HAM), an integrated manufacturing technology of 3D printing processes and other complementary processes, is becoming a competent candidate for conveniently delivering lattice structures with multifunctionalities, not just mechanical aspects. This work proposes a HAM technology that combines vat photopolymerization (VPP) and electroless plating process to fabricate smart metal-coated lattice structures. VPP 3D printing process is applied to create a highly precise polymer lattice structure, and thereafter electroless plating is conducted to deposit a thin layer of metal, which could be used as a resistive sensor for monitoring the mechanical loading on the structure. Ni-P layer and copper layer were successfully obtained with the resistivity of 8.2 × 10 − 7 Ω ⋅ m and 2.0   × 10 − 8   Ω ⋅ m , respectively. Smart lattice structures with force-loading self-sensing functionality are fabricated to prove the feasibility of this HAM technology for fabricating multifunctional polymer-metal lattice composites. [ABSTRACT FROM AUTHOR]

Fast preparation of Fe precisely regulated 3D dandelion spore-like Fe 1 -Ni 1 P@GF self-supported electrode by one-step mild electroless plating for efficient ultra-stable overall water splitting at ultra-high current density in harsh environments such as quasi-industrial conditions (6.0 M KOH + 0.5 M NaCl), high salt (1.0 M KOH + 3.0 M NaCl) and simulated domestic wastewater (1.0 M KOH + 0.5 M urea). [Display omitted] • Successful preparation of large-size, robust and stable Fe 1 -Ni 1 P@GF bifunctional catalytic electrodes with Fe element precisely regulated by one-step mild electroless plating on corrosion-resistant glass fiber surface. • The precise regulation of Fe improves the electronic conductivity and charge transfer capability, significantly reduces the overpotential, and promotes the generation of OER active materials. • Fe 1 -Ni 1 P@GF not only has excellent electrocatalytic activity, but also has long-term stability in extreme environments such as quasi-industrial conditions, simulated domestic wastewater and high salt. Construction of ultra-stable, flexible, efficient and economical catalytic electrodes is of great significance for the seawater electrolysis for hydrogen production. This work is grounded in a one-step mild electroless plating method to construct industrial-grade super-stable overall water splitting (OWS) catalytic electrodes (Fe 1 -Ni 1 P@GF) by growing loose and porous spore-like Fe 1 -Ni 1 P conductive catalysts in situ on flexible glass fibre (GF) insulating substrates with precise elemental regulation. Cost-effective Fe regulation boosts the electronic conductivity and charge transfer ability to achieve the construction of high intrinsic activity and strong electron density electrodes. Fe 1 -Ni 1 P@GF exhibits remarkable catalytic performance in hydrogen and oxygen evolution reaction (HER and OER), providing current densities of 10 mA cm−2 for HER and 100 mA cm−2 for OER at overpotentials of 51 and 216 mV, respectively. Moreover, it achieves 10 mA cm−2 at 1.42 V for OWS, and exhibits stable operation for over 1440 h at 1000 mA cm−2 in quasi-industrial environment of 6.0 M KOH + 0.5 M NaCl, without any performance degradation. This strategy enables the preparation of universally applicable P-based electrodes (ternary, quaternary, etc.) and large-area flexible electrodes (paper or cotton), significantly expands the practicality of the electrodes and demonstrating promising potential for industrial applications. [ABSTRACT FROM AUTHOR]

Structural and phase stability of the Pd-plated Ti3(Al, Si)C2–TiC composite at elevated temperatures was analyzed by the in situ X-ray diffraction method using synchrotron radiation. Porous Ti3(Al, Si)C2–TiC composite was prepared by spark plasma sintering of preceramic paper with 90 wt % of a Ti3(Al, Si)C2 powder filler at 1000°C and 20 MPa. The sintered composite was covered with a Pd film via electroless plating. During in situ investigation, the Pd-plated composite was linearly heated from 25 to 1000°C and annealed for 1 h at a maximum temperature. Structural and phase analysis reveals a formation of new Pd2Si, PdAl, and PdCx phases. It was noted that the newly formed phases began to be formed during heating at ~750°C. Scanning electron microscopy showed that the obtained Ti3AlSiC2–TiC composite had a well-developed porous structure where some pores were filled with Pd. After high-temperature treatment, Pd could be detected at depths up to 5 μm into the Ti3AlSiC2–TiC composite. [ABSTRACT FROM AUTHOR]

To meet the demands for flexible electromagnetic interference (EMI) shielding materials, a type of conductive fabric is prepared by generating three-dimensional (3D) porous laser-induced graphene (LIG) in situ on the surface of the aramid fabric (AF) and then electroless plating copper. After LIG treatment, the porous AF demonstrates admirable conductivity due to the generation of graphene. The superior surface resistance of the conductive fabric can reach 1.57 Ω/sq after copper deposition, and the average EMI shielding effectiveness (SE) can reach 34.3 dB in a frequency range of 8.2 to 12.4 GHz, with the EMW absorption accounting for about 80%. The proposed technology provides a new idea for preparation of flexible EMI shielding materials. [ABSTRACT FROM AUTHOR]

The wastewater containing phosphorus (P) and copper (Cu) is produced in large quantities during manufacturing processes such as electroless plating of Cu. The focus of this work is to develop a green and cost-efficient process for the co-removal of P and Cu from wastewater. An iron-enhanced dolomite process was employed to treat the phosphate (PO4–P) and copper contaminated water. The results showed that the co-removal of PO4–P and Cu was feasible by adjusting parameters as reagent dosage, molar ratio, stirring time, and pH. Under the conditions of Ca/Fe molar ratio of 4:1, Fe/(P+Cu) molar ratio of 1:1, initial pH of 5.6~10.0, and stirring for 30 min, the removal rates of PO4–P and Cu exceeded 99%. The mechanism research showed that the Fe ions was critical to the removal of PO4–P, which mainly removed by forming insoluble amorphous precipitate. The raw CaMg(CO3)2 is susceptible to corrosion by Cu ions and resulting in the production of flaky particles, which have two-dimensional nanostructured. The two-dimensional nanostructured is conducive to increase the contact area of particles with ions in solution, improving the chemical reactivity and adsorption. The Cu ions are likely to be removed in the form of posnjakite. The process has the advantages of being green and cost-efficient, and has a good practical application prospect for the PO4–P and Cu removal. [ABSTRACT FROM AUTHOR]

With increasing interest in the rapid development of lattice structures, hybrid additive manufacturing (HAM) technology has become a competent alternative to traditional solutions such as water jet cutting and investment casting. Herein, a HAM technology that combines vat photopolymerization (VPP) and electroless/electroplating processes is developed for the fabrication of multifunctional polymer-metal lattice composites. A VPP 3D printing process is used to deliver complex lattice frameworks, and afterward, electroless plating is employed to deposit a thin layer of nickel-phosphorus (Ni-P) conductive seed layer. With the subsequent electroplating process, the thickness of the copper layer can reach 40 μm within 1 h and the resistivity is around 1.9 × 10 − 8   Ω ⋅ m , which is quite close to pure copper ( 1.7   × 10 − 8   Ω ⋅ m ). The thick metal shell can largely enhance the mechanical performance of lattice structures, including structural strength, ductility, and stiffness, and meanwhile provide current supply capability for electrical applications. With this technology, the frame arms of unmanned aerial vehicles (UAV) are developed to demonstrate the application potential of this HAM technology for fabricating multifunctional polymer-metal lattice composites. [ABSTRACT FROM AUTHOR]

[Display omitted] Immunotherapy has revolutionized cancer therapy, using chemical or biological agents to reinvigorate the immune system. However, most of these agents have poor tumor penetration and inevitable side effects that complicate therapeutic outcomes. Electrical stimulation (ES) is a promising alternative therapy against cancers that does not involve chemical or biological agents but is limited in the fabrication and operation of complex micrometer-scale ES devices. Here, we present an optically microprinted flexible interdigital electrode with a gold-plated polymer microneedle array to generate alternating electric fields for cancer treatment. A flexible microneedle-array-integrated interdigital electrode (FMIE) was fabricated by combining optical 3D microprinting and electroless plating processes. FMIE-mediated ES of cancer cells induced necrotic cell death through mitochondrial Ca2+ overload and increased intracellular reactive oxygen species (ROS) production. This led to the release of damage-associated molecular patterns that activated the immune response and potentiated immunogenic cell death (ICD). FMIE-based ES has an excellent safety profile and systemic anti-tumor effects, inhibiting the growth of primary and distant tumors as well as melanoma lung metastasis. FMIE-based ES-driven cancer immunomodulation provides a new pathway for drug-free cancer therapy. [ABSTRACT FROM AUTHOR]

Combining the design flexibility and rapid prototyping capabilities of additive manufacturing with photocatalytic and plasmonic functionalities is promising for the development of next-generation SERS applications such as point of care diagnostics and in situ monitoring of chemical reactions in fuels and chemical processing. Laser powder bed fusion (LPBF) is a well-matured additive manufacturing technique which generates metallic structures through localised melting and joining of metal powders using a laser. LPBF reduces material wastage during manufacturing, is applicable to a wide range of metals and alloys, and allows printing of complex internal structures. This feature article elaborates the use of soot templating, chemical vapour deposition and electroless plating techniques for grafting plasmonic and semiconductor nanoparticles on the surface of LPBF manufactured metallic substrates. The capability to fabricate different types of intricate metallic lattices using additive manufacturing is demonstrated and technical challenges in their adequate functionalization are elaborated. The developed methodology allows tailoring of the substrate structure, composition, morphology, plasmonic and photocatalytic activities and thus unveils a new class of recyclable SERS substrates. [ABSTRACT FROM AUTHOR]

As society becomes smarter, advanced optical sensing and imaging technologies utilizing visible and near-infrared regions have become increasingly prevalent. Wire-grid polarizers, which are available for broadband electromagnetic waves, are effective in improving the signal-to-noise ratio of such optical systems and enabling more advanced object detection and analysis. However, to be implemented in everyday products, low-cost manufacturing methods must be developed while maintaining high-performance optical functions. To meet these requirements, we conducted an analysis of the geometry of wire-grid polarizers, and designed and developed a wire-grid polarizer with a nano-triangular wave-shaped structure that can be fabricated using general-purpose manufacturing equipment. Once the mould is prepared, this polarizer can be fabricated via nanoimprinting and metal deposition with a normal angle or electroless plating processes. The polarizer fabricated through electroless Ni plating achieves a transmittance of 40%, which is approximately 1.4 times higher than that achieved in a previous study using electroless Ni plating on a rectangular structure with the same period. In addition, the polarizer fabricated through normal angle Al deposition operates over a wide range of wavelengths from visible light to near-infrared, and achieves a polarization extinction ratio of 24 dB at a wavelength of 550 nm and a high transmittance of 81%. High-performance polarizers can be obtained through normal-angle deposition using general-purpose equipment in contrast to the oblique-angle deposition method employed in the manufacture of conventional rectangular structure-based wire-grid polarizers, thereby contributing to cost reduction and improved manufacturability. [ABSTRACT FROM AUTHOR]

Yttrium-stabilized zirconia(3YSZ) microspheres with different size ranges were prepared by sol-gel method, followed by electroless Ni plating on their surfaces. The as-prepared core-shell structure 3YSZ/Ni microspheres were then spark plasma sintered (SPS) into 3YSZ/Ni composites, in which a uniform distribution of ceramic and metal phases was achieved. The underlying correlations among microsphere size, Ni concentration, microstructure, and resultant mechanical properties were experimentally analyzed. Results show that: continuous and smaller microsphere sizes can obtain relatively high-density samples with good mechanical properties, which can be proved by the Minimum Solid Area (MSA) model. 3YSZ sample prepared with the optimized microsphere size range of 0–50 μm exhibits the highest relative density and fracture toughness of 98.8% and 5.51 ± 0.33 MPa·m1/2, respectively. Furthermore, the core-shell structure 3YSZ/Ni microspheres with varying Ni contents exhibited a uniform composite of flakes and particles Ni metal after sintering, among which 3YSZ/10 wt%Ni composites have achieved better mechanical properties, with density, hardness and fracture toughness of 96.9%, 8.61 ± 0.35 GPa, 7.92 ± 0.71 MPa·m1/2, respectively. Firstly, the uniformly dispersed Ni metal flakes or particles provide multiple toughening effects, including crack bridging, pull-out, interfacial debonding, crack deflection, etc. Secondly, due to residual stress, cracks tend to deflect near Ni metal, extending the crack path. Thirdly, the 3YSZ matrix's transition from an intergranular to a transgranular fracture also increases fracture energy consumption. Compared to the pure 3YSZ sample with a wide microsphere size range of 0–100 μm, the fracture toughness of 3YSZ/10 wt%Ni composites with a microsphere size of 0–50 μm is increased by 73.9%. [ABSTRACT FROM AUTHOR]

A novel approach for fabricating copper‐coated alumina microparticles utilizing a pectin‐based coating subsequently followed by electroless deposition is reported. The biopolymer pectin is modified with phosphate groups covalently binding to the particle surface, while the polymer itself promotes the formation of metal centers on the surface due to the high affinity to metal cations. The sugar‐based (galactose, xylose, and glucose) electroless plating process in combination with an organic‐based treatment ensures a homogeneous metal coating method. As a benefit, precious metal activation of alumina particles and hazardous reducing agents typically employed are not required, creating a low‐cost and sustainable process. Metal plated micro particles show a uniform and homogeneous coating rendering them as ideal additives for application in metal matrix composites. These ceramic metal composites can be used in a wide range of applications where high‐strength metal components are needed. [ABSTRACT FROM AUTHOR]

With the rapid development of electronic technology, the electroless copper–nickel plating process produces a significant amount of copper–nickel complex wastewater. The traditional methods face difficulties in achieving wastewater treatment and recovering valuable metal resources. In this study, we propose a new environmentally friendly and efficient treatment process for the separation and recovery of Cu(II) and Ni(II). The photocatalyst TiO2-500, calcined at 500 °C, exhibits excellent photo-reduction performance, selectively reducing Cu(II) in the hybrid wastewater to copper. Even after 5 cycles, TiO2-500 photocatalyst maintains good catalytic performance. Following Cu removal, the remaining Ni(II) in the residual wastewater is effectively adsorbed by a chitosan (CS) membrane with an adsorption capacity of 76.7 mg/g. The separation ratio of Cu–Ni reaches 6290.37 in the photocatalytic process. We conducted a comprehensive investigation of the factors that influence the selective recovery of Cu and Ni ions. Our findings reveal that the disparity in reduction potentials between Cu2+ and Ni2+ plays a crucial role in achieving effective separation of Cu and Ni in chemical plating wastewater through photocatalysis. Specifically, under the experimental conditions described in this paper, the reduction potential of Ni2+ (E(Ni2+/Ni) = − 0.33 V) presents a significant challenge for its photoreduction on TiO2-500, which has a conduction potential of − 0.31 V. Moreover, the catalyst surface carries a positive charge and exhibits weak adsorption of Ni2+, resulting in the majority of Ni2+ ions remaining in solution. This characteristic facilitates subsequent adsorption and separation of Ni2+ ions.Additionally, we further elucidated the mechanisms underlying these two processes. The establishment of this process holds immense significance for treating Cu–Ni mixed wastewater and recovering valuable heavy metal resources. [ABSTRACT FROM AUTHOR]

The ternary nickel–phosphorus–boron coatings were prepared on LA43M alloy substrate by electroless plating. The influences of different concentrations of Lanthanum ion on the microstructure, the deposition rate, the content of phosphorus, and anticorrosion performance of the coatings were researched by using SEM, EDS, and potentiodynamic polarization methods. The contact angle and Fourier transform infrared spectroscopy were used to characterize the coatings surface. The results showed that La3+ had obvious impacts on the properties of the coatings, for example, the sizes of cauliflower-like clusters got smaller and the corrosion current density of the coatings was reduced apparently. While La3+ concentration was 1.5 mmol L–1, its strong adsorption resulted in the deposition rate increasing a maximum of 5.89 mg cm–2 h–1. With the increase in La3+ concentration, the corrosion rate of the coatings first declined and then increased. However, the excessive addition of La3+ in the bath led to a decrease in corrosion resistance. The coatings exhibited good superhydrophobic performance and self-cleaning properties. [ABSTRACT FROM AUTHOR]

Electroless metallisation is a modern method for obtaining thin layers of metals and their alloys on various dielectric materials, which are increasingly used in various industries. One of the important stages in the pretreatment of the polymers for the chemical processes is the etching operation. It ensures surface roughening of the dielectric materials in order to improve the adhesion strength between the electroless deposited metal coating and the acrylonitrile–butadiene-styrene (ABS) substrate. Most often, this operation in practice is carried out in a chromic-sulphuric acid solution. In this work, investigations are carried out aiming to replace the harmful high chromium solution with an environmentally friendly one. A suitable environmentally friendly etching solution is proposed, with an optimal composition of the solution and working conditions. It can be used in the pretreatment of the ABS substrate for the subsequent deposition of copper or nickel coatings from the corresponding solutions with and without a reducer. [ABSTRACT FROM AUTHOR]

2A12 aluminum alloy was pretreated with dopamine instead of the traditional zinc dipping, and then Ni--P alloy coating was formed on its surface by electroless plating in an alkaline bath and an acidic bath successively. The hydrophilicity of 2A12 aluminum alloy was greatly improved after being treated with dopamine due to the massive formation and strong adsorption of polydopamine (PDA) particles on its surface. The Ni--P alloy coating electrolessly plated in the acidic bath was amorphous, uniform, and compact, contained 11.56% of phosphorus by mass, and had a microhardness of 320 HV, providing good protection for the substrate. [ABSTRACT FROM AUTHOR]

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In this study, in order to achieve high‐yield Micro‐LED chip bonding and thus further advance the breakthrough of Micro‐LED interconnect technology. In this study, an electroless plating method is used to achieve the highly uniform nickel bump arrays on thin film transistor (TFT) driver substrate. Initially, the photoresists AZ4620 and AZ2070 are chosen for the experiments, which can cover the step structure uniformly of TFT substrate. Subsequently, the morphology of bumps on the TFT substrate influenced by the plasma treatment and the deposition time is investigated. The 1% uniformity of the nickel bump arrays by the electroless plating for 30 minutes after 5‐minute plasma treatment is achieved, which lays the foundation for the electroless plating self‐bonding. [ABSTRACT FROM AUTHOR]

In order to better understand the advantages and disadvantages of Ni-P and Ni-Cu-P coatings, Ni-P and Ni-Cu-P coatings were deposited on surface of polyether ether ketone (PEEK) by electroless plating. Deposition rates of electroless Ni-P coating and Ni-Cu-P coating under different processes were compared. Surface morphology, composition and structure of the coatings were investigated through scanning electron microscope (SEM), energy-dispersive spectrometer (EDS) and X-ray diffractometer (XRD). Microhardness tester, surface roughness tester and MM-200 wear testing machine were used to evaluate the hardness, surface roughness and wear resistance of the coatings. The electrochemical performance and electromagnetic shielding performance of coatings were compared and studied through electrochemical performance and electromagnetic shielding performance tests. Results showed that electroless Ni-Cu-P coating had higher deposition rate. Ni-Cu-P coating was of a dense mixed crystal cauliflower-like structure, with higher hardness, better wear resistance in the later stage of wear, and better electromagnetic shielding performance. Whereas, the Ni-P coating was of a dense amorphous nodular structure with a smoother surface, better wear resistance in the early stage of wear, and better electrochemical performance.

Double-layer Ni-P coatings with low phosphorus content in the inner layer and high phosphorus content in the outer layer and Ni-Mo-P composite coatings are successfully prepared on the surface of AZ91D magnesium alloy by chemical plating process. The microstructures, friction and corrosion resistance of double-layer Ni-P and Ni-Mo-P coatings are studied in comparison. Meanwhile, the deposition and corrosion resistance mechanism for the coatings are investigated. Results convey that both Ni-P and Ni-Mo-P coatings showcase an amorphous structure. The coating possesses denser and more homogeneous structure with the co-doping of Mo. The micro-indentation hardness (859.7 HV) and friction coefficient (0.58) of Ni-Mo-P coatings show that the ternary alloy coating is firmly bonded to the magnesium alloy substrate. Besides, the Ni-Mo-P coatings demonstrate exceptional wear resistance attributed to Mo co-deposition, fostering grain refinement and facilitating the growth of passivation films.

Abstract A novel approach for fabricating copper‐coated alumina microparticles utilizing a pectin‐based coating subsequently followed by electroless deposition is reported. The biopolymer pectin is modified with phosphate groups covalently binding to the particle surface, while the polymer itself promotes the formation of metal centers on the surface due to the high affinity to metal cations. The sugar‐based (galactose, xylose, and glucose) electroless plating process in combination with an organic‐based treatment ensures a homogeneous metal coating method. As a benefit, precious metal activation of alumina particles and hazardous reducing agents typically employed are not required, creating a low‐cost and sustainable process. Metal plated micro particles show a uniform and homogeneous coating rendering them as ideal additives for application in metal matrix composites. These ceramic metal composites can be used in a wide range of applications where high‐strength metal components are needed.

Hydrogen has recently become a prized resource to generate clean power owing to its massive energy content and harmless emissions produced during its combustion. However, other gases are always attached to hydrogen during its production via various routes. Therefore, the obtainment of hydrogen with high purity for use in energy production is generally questionable. In agreement with that goal, this study is directed toward the synthesis of activated-carbon-supported nickel nanoparticles as a novel composite membrane for hydrogen separation from gas mixtures. First, a type of solid residual (sawdust) was converted via thermochemical treatment into particles of activated carbon, which have enhanced surface properties. These carbon particles were then metalized by nickel nanoparticles using an electroless plating (ELP) technique. The obtained composite was subsequently turned into a disk-like membrane using hydraulic pressing, and was then thermally treated at high temperature to generate a dense-layered Ni membrane. Full characterization on a comparative basis between the blank and metalized carbon particles was carried out using X-ray diffraction (XRD), Fourier Transform infrared (FT-IR) spectroscopy, BET surface area analysis, transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA). The efficiency of the Ni-based membrane toward H2 separation was next tested through the use of gas mixtures composed of different hydrogen-to-nitrogen concentrations. A maximum hydrogen flux and hydrogen-to-nitrogen selectivity of 15.16 sccm cm−2 min−1 and 465, respectively, were attained at ambient temperature. Additionally, a hydrogen permeability percentage of nearly 80% (from the original H2 stream) could be achieved by the designed Ni-membrane, which could offer synchronized hydrogen storage during the separation process. [ABSTRACT FROM AUTHOR]

A microwave transmitter/receiver using the low-temperature co-fired ceramic substrate and ball grid array packaging demonstrates superior properties, including high integration, miniaturization, and high electromagnetic shielding. However, it holds limitations of inadequate hermeticity (that is, gas or moist impermeability), high cost, and low reproducibility. In this work, we aim to overcome these difficulties by introducing a new packing technique. The packaging utilizes an electroless plated Ni/Pd/Au surface, resulting in a significant enhancement of the packaging hermeticity by orders of magnitude, approaching the level of <5 × 10−9 Pa·m3/s. Both Sn63Pb37 and Au80Sn20 solder alloys demonstrate exceptional solderability, attributed to Pd atoms diffusing to the Au layer during soldering at 310 °C. A reliability test of the packaging shows that the shear strength of the solder balls drops after thermal shocks but negligibly affects the hermeticity of the packaging. Furthermore, a meticulously designed internal vertical interconnect structure and I/O interconnections were engineered in the ball grid array packaging, showcasing excellent transmission characteristics within the 10–40 GHz frequency range while ensuring effective isolation between ports. [ABSTRACT FROM AUTHOR]

[Display omitted] Advanced Ag nanoparticles (Ag NPs) were prepared by wet chemical oxidation–reduction method, using mainly the tannic acid as reducing agent and carboxymethylcellulose sodium as stabilizer. The prepared Ag NPs uniformly disperse and are stable for more than one month without agglomeration. The studies of transmission electron microscopy (TEM) and ultraviolet–visible (UV–vis) absorption spectroscopy indicate that the Ag NPs are in homogeneous sphere with only 4.4 nm average size and narrow particle size distribution. Electrochemical measurements reveal that the Ag NPs behave excellent catalytic activity for electroless copper plating using glyoxylic acid as reducing agent. In situ fourier transform infrared (in situ FTIR) spectroscopic analysis combined with density functional theory (DFT) calculation illustrate that the molecular oxidation of glyoxylic acid catalyzed by Ag NPs is as the following routes: glyoxylic acid molecule first is adsorbed on Ag atoms with carboxyl oxygen terminal, then hydrolyzed to diol anionic intermediate, and last oxidized to oxalic acid. Time-resolved in situ FTIR spectroscopy further reveals the real-time reactions of electroless copper plating as follows: glyoxylic acid is continuously oxidized to oxalic acid and releases electrons at the active catalyzing spots of Ag NPs, and Cu(II) coordination ions are in situ reduced by the electrons. Based on the excellent catalytic activity, the advanced Ag NPs can replace the expensive Pd colloids catalyst and successfully apply in through-holes metallization of printed circuit board (PCB) by electroless copper plating. [ABSTRACT FROM AUTHOR]