Clean Metal Surfaces Research Articles

LEED-IV analyses of tellurium adsorbate structures on iridium and gold surfaces

The determination of the configuration of atomic adsorbates on clean metal surfaces has been a key issue in surface science 60 years ago and still is today. We demonstrate that despite the prevalence of combined scanning tunneling microscopy and density functional theory studies of adsorbate systems the pitfalls are plentiful calling for accurate, reliable structure analyses that can be delivered by diffraction methods. We analyze and compare the ordered phases of Te on Ir(111), Ir(100), and Au(100) demonstrating the accuracy, the in-depth information and physical insight that can nowadays be obtained by quantitative low-energy electron diffraction structural analyses.

SURFACE QUALITY AND CORROSION RESISTANCE OF 316L STAINLESS STEEL ELECTROPOLISHED USING PHOSPHORIC – SULFURIC ACIDS

Electropolishing is an electrochemical surface finishing technique. It is commonly applied to equipment that requires a gleaming finish. This surface property is frequently required in 316L stainless steel (SS) medical implants. Electropolishing removes a thin layer from the metal's surface through electrochemical processes. This results in a very clean, smooth, and bright metal surface. The process parameters, such as electrolyte solution, electrical current, and electropolishing time, influence surface roughness and glossiness. The dissolution of metallic ions during the process may also affect the corrosion resistance of the treated material in addition to producing a shiny surface. This study investigated the surface glossiness, surface roughness, and corrosion of electropolished 316L SS. Electropolishing experiments on 316 SS were carried out using various H3PO4 (50%) and H2SO4 (32%) electrolyte solution compositions. The influences of electrolyte solution composition, electric current, and electropolishing time were studied. The results showed that increasing the H2SO4 content of the mixture and electropolishing the 316L SS for a longer period of time improved the surface roughness and glossiness. Under 10 Amp electric currents, the best surface glossiness was discovered. A corrosion test revealed that the electropolishing produced a Cr and Ni-rich layer that improved the corrosion resistance of the samples.

DFT Investigation of CH4 and H2O Adsorption on Pd (111), Ni (111), Pt (111), and Ir(111) Surfaces

Using density functional theory (DFT) calculations, the surface Gibbs free energy of methane and water adsorption on Pt(111), Ir(111), Ni(111), and Pd(111) surfaces was investigated. DFT computations were employed to investigate the adsorption of methane and water molecules on unit cells with varying coverage levels of 0.11, 0.25, 0.50, and 1.00 monolayers and the aggregation of H2O over clean transition metal surfaces. The adsorption configuration was assessed to experimental findings to evaluate our computational approaches' accuracy and reliability. A thermodynamic diagram was constructed for exploring the adsorption of CH4 and H2O on metal surfaces. The order of the methane adsorption energies on different metal surfaces is as follows: Pd(111) > Pt(111) > Ni(111) > Ir(111). A more significant number of H2O molecules on the transition metal surfaces reduces the contact between the metal surfaces and water molecules during water aggregation. The thermodynamic stability of water and methane adsorption coverage was found to be best on the Pt(111) surface.

Comparative theoretical study of CO2 activation on clean and potassium-preadsorbed low index surfaces of transition metals.

The efficient catalysis of CO2 adsorption and activation presents a formidable challenge due to its pronounced thermodynamic stability and kinetic inertia. Previous experiments have left gaps in understanding the promotional effects and underlying mechanism of potassium. In this study, we systematically investigate CO2 adsorption and activation on clean and potassium-preadsorbed low index surfaces of transition metals. Theoretical results reveal a substantial augmentation in CO2 binding strength when potassium is introduced, concomitant with a general reduction in activation energies. Notably, linear correlations are significant on close-packed metal surfaces without and with potassium additive. Through a comprehensive analysis encompassing geometric parameters, electronic structures, and energy decomposition, we discern the physical underpinnings of the potassium effect. This enhancement is primarily ascribed to direct electron transfer and dipole-dipole interactions. Furthermore, we scrutinize the impact of an external electric field, demonstrating that the application of a negative electric field accelerates CO2 activation, mirroring the effects observed with potassium. All the periodic density function theory (DFT) calculations were performed by the Vienna Ab Initio Simulation package (VASP). The interaction between nucleus and valence electron was described using the pseudopotentials found in the projector augmented wave method (PAW). Throughout the entire work, the Bayesian error estimation functional (BEEF) was used.

Effectiveness of Ultra-High Irradiance Blue Light-Emitting Diodes in Inactivating Escherichia coli O157:H7 on Dry Stainless Steel and Cast-Iron Surfaces.

The use of blue light-emitting diodes (LEDs) is emerging as a promising dry decontamination method. In the present study, LEDs emitting ultra-high irradiance (UHI) density at 405 nm (842 mW/cm2) and 460 nm (615 mW/cm2) were used to deliver high-intensity photoinactivation treatments ranging from 221 to 1107 J/cm2. The efficacy of these treatments to inactivate E. coli O157:H7 dry cells was evaluated on clean and soiled stainless steel and cast-iron surfaces. On clean metal surfaces, the 405 and 460 nm LED treatment with a 221 J/cm2 dose resulted in E. coli reductions ranging from 2.0 to 4.1 log CFU/cm2. Increasing the treatment energy dose to 665 J/cm2 caused further significant reductions (>8 log CFU/cm2) in the E. coli population. LED treatments triggered a significant production of intracellular reactive oxygen species (ROS) in E. coli cells, as well as a significant temperature increase on metal surfaces. In the presence of organic matter, intracellular ROS generation in E. coli cells dropped significantly, and treatments with higher energy doses (>700 J/cm2) were required to uphold antimicrobial effectiveness. The mechanism of the bactericidal effect of UHI blue LED treatments is likely to be a combination of photothermal and photochemical effects. This study showed that LEDs emitting monochromatic blue light at UHI levels may serve as a viable and time-effective method for surface decontamination in dry food processing environments.

Microstructural Investigation of Some Bronze Artifacts Discovered in a Dacian Site Using Non-Destructive Methods

Dacian civilization flourished on the actual territory of Romania during the Late Iron Age and had its peak from the first century BC to the first century AD. They had intensive relations with Hellenistic and Roman civilizations. Therefore, it is difficult to evaluate the origin of some widely spread artifacts discovered in the Dacian archeological sites. The present research is focused on two bronze artifacts (a bronze coin and a mirror fragment) found in the Alun-Piatra Rosie site and a silver coin found in the Ardeu site. Artifacts were investigated with nondestructive methods such as SEM-EDX for microstructural and elemental characterization, and the crystalline phases were investigated using XRD. Bronze coin proves to be an Istrian issue having an elemental composition of 75.0% Cu, 20.8% Sn, and 4.1% Pb, which corresponds to a structure of Cu grains mixed with Cu5.6Sn grains. The bronze mirror fragment has an elemental composition of 52.3% Cu and 47.7% Sn, which corresponds to a structure containing grains of Cu6Sn5 mixed with grains of Cu41Sn11. It has a smooth surface that was investigated with AFM microscopy, which evidences a Ra roughness of 51 nm for the patina surface and 33.7 nm for the clean metal surface, proving the high quality of the original mirror luster of the artifact. The silver coin was identified as a Radulesti–Hunedoara type meaning that it was produced in local Dacian metallurgic workshops. It has an elemental composition of 63.1% Ag, 25.3% Sn, 7.8% Cu, and small traces of P and Fe, which corresponds to a structure of Ag grains and Ag3Sn grains. Silver coins show that Dacians uses Sn as alloying element in their metallurgic workshops. Istrian bronze coin proves to be typical for Hellenistic or Roman bronze type with Sn content no more than 25% Sn. The bronze mirror fragment has an unusual composition that might be a result of al local metal charge elaboration with several Hellenistic and Roman bronze pieces as raw material and an extra Sn addition during the melting process. This material facilitates the polishing properties of the active surface that has a very low roughness even after 2000 years of ground resting and adherent oxides patina.

Syntheses and crystal structures of three salts of sparfloxacin, one incorporating extended tapes of fused pentagonal water assemblies

Three organic salts of sparfloxacin, a difluorinated third-generation fluoroquinolone antibiotic, have been synthesized and their crystal structures determined. The salts, sparfloxacinium 4-nitrobenzoate dihydrate, C19H23F2N4O3 +·C7H4NO4 −·2H2O (I), sparfloxacinium 2-phenylacetate, C19H23F2N4O3 +·C8H7O2 − (II), and sparfloxacinium 4-methylbenzoate trihydrate, C19H23F2N4O3 +·C8H7O2 −·3H2O (III), exhibit similar inter-species packing interactions. The overall crystal structures each, however, have their own distinct characteristics, which are described here along with a Hirshfeld surface analysis of the various atom–atom contacts involving the sparfloxacinium cations. In the crystal structure of III, an extended supramolecular tape of edge-fused hydrogen-bonded water pentagons was found. These pentagonal water and tape motifs are compared to related constructs in a broad selection of structure types, ranging from macromolecules to small molecules, clathrates, and exotic `ice' formations on clean metal surfaces.

Hydrogen Evolution Volcano(es)—From Acidic to Neutral and Alkaline Solutions

As the global energy crisis continues, efficient hydrogen production is one of the hottest topics these days. In this sense, establishing catalytic trends for hydrogen production is essential for choosing proper H2 generation technology and catalytic material. Volcano plots for hydrogen evolution in acidic media are well-known, while a volcano plot in alkaline media was constructed ten years ago using theoretically calculated hydrogen binding energies. Here, for the first time, we show that the volcano-type relationships are largely maintained in a wide range of pH values, from acidic to neutral and alkaline solutions. We do this using theoretically calculated hydrogen binding energies on clean metallic surfaces and experimentally measured hydrogen evolution overpotentials. When metallic surfaces are exposed to high anodic potentials, hydrogen evolution can be boosted or significantly impeded, depending on the type of metal and the electrolyte in which the reaction occurs. Such effects are discussed here and can be used to properly tailor catalytic materials for hydrogen production via different water electrolysis technologies.

Identification and Classification of Aluminum Scrap Grades Based on the Resnet18 Model

In order to reduce the elemental species produced in the recycling and melting of aluminum scrap and to improve the quality of pure aluminum and aluminum alloys, it is necessary to classify the different grades of aluminum scrap before melting. For the problem of classifying different grades of aluminum scrap, most existing studies are conducted using laser-induced breakdown spectroscopy for identification and classification, which requires a clean and flat metal surface and enormous equipment costs. In this study, we propose a new classification and identification method for different grades of aluminum scrap based on the ResNet18 network model, which improves the identification efficiency and reduces the equipment cost. The objects of this research are three grades of aluminum scrap: 1060, 5052, and 6061. The surface features of the three grades were compared using a machine vision algorithm; three different datasets, using RGB, HSV, and LBP, were built for comparison to find the best training dataset for subsequent datasets, and the hyperparameters of learning rate and batch size were tuned for the ResNet18 model. The results show that there was a differentiation threshold between different grades through the comparison of surface features; the ResNet18 network model trained the three datasets, and the results showed that RGB was the best dataset. With hyperparameter optimization of the ResNet18 model, the accuracy of final classification and recognition could reach 100% and effectively achieve the classification of different grades of aluminum scrap.

The Winner Takes It All: Carbon Supersedes Hexagonal Boron Nitride with Graphene on Transition Metals at High Temperatures.

The production of high-quality hexagonal boron nitride (h-BN) is essential for the ultimate performance of 2D materials-based devices, since it is the key 2D encapsulation material. Here, a decisive guideline is reported for fabricating high-quality h-BN on transition metals. It is crucial to exclude carbon from the h-BN related process, otherwise carbon prevails over boron and nitrogen due to its larger binding energy, thereupon forming graphene on metals after high-temperature annealing. The surface reaction-assisted conversion from h-BN to graphene with high-temperature treatments is demonstrated. The pyrolysis temperature Tp is an important quality indicator for h-BN/metals. When the temperature is lower than Tp , the quality of the h-BN layer is improved upon annealing. While the annealing temperature is above Tp , in case of carbon-free conditions, the h-BN disintegrates and nitrogen desorbs from the surface more easily than boron, eventually leading to clean metal surfaces. However, once the h-BN layer is exposed to carbon, graphene forms on Pt(111) in the high-temperature regime. This not only provides an indispensable principle (avoid carbon) for fabricating high-quality h-BN materials on transition metals, but also offers a straightforward method for the surface reaction-assisted conversion from h-BN to graphene on Pt(111).

Wettability of Metal Surfaces Affected by Paint Layer Covering.

The aim of the work was to quantify the surface wettability of metallic (Fe, Al, Cu, brass) surfaces covered with sprayed paints. Wettability was determined using the contact angle hysteresis approach, where dynamic contact angles (advancing ΘA and receding ΘR) were identified with the inclined plate method. The equilibrium, ΘY, contact angle hysteresis, CAH = ΘA − ΘR, film pressure, Π, surface free energy, γSV, works of adhesion, WA, and spreading, WS, were considered. Hydrophobic water/solid interactions were exhibited for the treated surfaces with the dispersive term contribution to γSV equal to (0.66–0.69). The registered 3D surface roughness profiles allowed the surface roughness and surface heterogeneity effect on wettability to be discussed. The clean metallic surfaces turned out to be of a hydrophilic nature (ΘY < 90°) with high γSV, heterogeneous, and rough with a large CAH. The surface covering demonstrated the parameters’ evolution, ΘA↑, ΘR↑, γSV↓, WA↓, and WS↓, corresponding to the surface hydrophobization and exhibiting base substratum-specific signatures. The dimensionless roughness fluctuation coefficient, η, was linearly correlated to CAH. The CAH methodology based on the three measurable quantities, ΘA, ΘR, and liquid surface tension, γLV, can be a useful tool in surface-mediated process studies, such as lubrication, liquid coating, and thermoflow.

Ionization probability of atoms sputtered under bombardment of metal surface with single and multiply charged ions

The processes of ionization of atoms sputtered under bombardment of clean metal surface by singly and multiply charged ions with kinetic energy of several keV were studied. Within the framework of simple phenomenological model of ion formation, the relaxation of local electron excitation in metal was taking into account. Analytical expressions for estimation of ionization probability of sputtered atoms was obtain. It was shown, that in comparison with singly charged ions, bombardment of metals with multiply charged ions results to significant increase of ionization probability of sputtered atoms due to more efficient excitation of electrons and increase of relaxation time of this excitation. Keywords: ion sputtering, ionization probability, multiply charged ions, Auger electrons, collision cascades, secondary ion mass spectrometry.

Вероятность ионизации атомов, распыленных при бомбардировке поверхности металлов одно- и многозарядными ионами

The processes of ionization of atoms sputtered under bombardment of clean metal surface by singly and multiply charged ions with kinetic energy of several keV were studied. Within the framework of simple phenomenological model of ion formation, the relaxation of local electron excitation in metal was taking into account. Analytical expressions for estimation of ionization probability of sputtered atoms was obtain. It was shown, that in comparison with singly charged ions, bombardment of metals with multiply charged ions results to significant increase of ionization probability of sputtered atoms due to more efficient excitation of electrons and increase of relaxation time of this excitation.

ПОВЫШЕНИЕ ЭКСПЛУАТАЦИОННЫХ СВОЙСТВ ПЛАСТИЧНЫХ СМАЗОК ГРАФЕНОВЫМИ ДОБАВКАМИ

It is known that commercial lubricants do not always meet high performance requirements in terms of their tribological characteristics. In particular, it was found that at high loads in worn mechanisms, Litol-24 grease does not always provide high anti-wear properties that help extend the service life of plain bearings. In order to improve the performance properties, studies were carried out on the modification of the lubricant with numerous graphenes and comparative tests were carried out on the MI-1M friction machine. The structure of the carbon film was determined by Raman scattering on a DXR Raman Microscope Thermo Scientific spectrometer. As a result of the research, it was found that the modification of the lubricant with graphenes makes it possible to form a film on the friction surface. At the same time, the wear of parts is reduced from 0.0138 mg on the Litol-24 commercial lubricant to 0.0079 on the graphene-modified lubricant. As a result of spectral analysis, it was determined that the spectrum of the carbon film contains approximately the same intensity G-line - 1565 cm-1 and D-line - 1340 cm-1 and a low-intensity 2D line - 2700 cm-1. This spectrum is identical to the Raman spectrum of amorphous carbon. In the spectrum from the metal surface of the roller, the listed lines of the Raman spectrum are absent. In the process of testing on a friction machine of Litol 24 plastic lubricant with multilayer graphene filler, the destruction of the graphene structure and its transformation into amorphous carbon is observed. As a result of determining the roughness of the roller and the thickness of the carbon film with a profilometer, it was found that the surface roughness with a carbon film is less compared to the clean metal surface of the roller: (0.176 - 0.168 = 0.008 μm) and (0.566 - 0.485 = 0.071 μm), the depth of the profile depressions on the surface with carbon film decreased by 0.116 µm. The height of the protrusions of the profile on the surface with the carbon film increased by 0.161 µm. At the same time, it was determined by calculation that the approximate thickness of the carbon film is 0.138 μm. On the basis of the conducted studies, it can be argued that the modification of Litol-24 commercial lubricant with graphenes contributes to the formation of a protective anti-wear film on the friction surface, thereby reducing wear and increasing the service life of machine parts.

Plasma electrolytic processing of bimetals at the anodic process

Bimetals have a unique combination of functional characteristics, which are not inherent to components. Usually, the joining is the final procedure of the bimetals manufacturing because the conditions of heat or thermochemical treatment of the bimetal components are very different. Plasma electrolytic processing is a highly effective and environmentally friendly method to process surfaces of metals and alloys. This technology can be used for heat or thermochemical treatment as well as to clean or polish metal surfaces. Due to the voltage ranges of different modes of the anodic process of plasma electrolytic processing for various metals in the same electrolyte partially overlaps, the components of bimetals can be treated identically or differently. It is demonstrated that there exists an option of separate or simultaneous heat or thermochemical treatment, as well as polishing of one or both components of bimetals. For example, in Ti / Stainless Steel (SS) bimetal, the steel was heated up to 620°C, in Mo / SS one — up to 630°C, in Al / SS one — up to 720 ÷ 850°C without heating of the second component higher than 140°C. Also, an ability of simultaneous polishing of both components of Al / SS bimetal was shown. During 8 min polishing, the reflection coefficients of both surfaces increase from 0.5 ÷ 2 % to >40 %.

High-resolution observation of cathodic arc spots in a magnetically steered arc plasma source in low pressure argon, nitrogen, and oxygen atmospheres

Cathode spots in a magnetically steered arc source were studied under low-pressure noble gas (Ar) and reactive gas (N2, O2) atmospheres. The plasma was observed using a streak camera coupled with a long-distance microscope to study the evolution of cathode spots with high temporal and spatial resolution. We find two well-known types of cathode spots: “type 1” for less bright spots eroding the compound layer on the cathode surface and bright “type 2” spots on (clean) metallic surfaces. Cathode spots are characterized by a sequence of microexplosions that give the impression of a moving spot, which, in the presence of a magnetic field, is generally in the retrograde direction. However, the apparent displacement can also go in the opposite, the Amperian direction, especially when nitrogen is present. In oxygen, spot ignition often happens in approximately the same location repeatedly. For type 2 spots, we detected an apparent motion mainly in the retrograde direction with distinct jumps to new locations. Via the effects of spot appearance, we note the competing effects of cathode cleaning by spot-induced material removal (erosion) and compound formation in the presence of reactive gas. The streak images were analyzed by fast Fourier transformation, and we found that the arc fluctuations are stochastic without specific frequencies. The colored random noise (CRN) index tends to be reduced in the presence of a compound layer, indicating an enhanced spot ignition probability. A reduced CRN index implies reduced feedback (influence) of previously active spots, which is most apparent in the presence of elevated oxygen pressure.

Initial Stages of Oxide Formation on Copper Surfaces during Oxygen Bombardment at Room Temperature

We have studied the oxidation kinetics of initial stages of oxide formation on clean metallic copper surfaces during low-energy O2+ bombardment at room temperature using X-ray photoelectron spectro...

Enhanced condensation heat transfer using porous silica inverse opal coatings on copper tubes

Phase-change condensation is commonplace in nature and industry. Since the 1930s, it is well understood that vapor condenses in filmwise mode on clean metallic surfaces whereas it condenses by forming discrete droplets on surfaces coated with a promoter material. In both filmwise and dropwise modes, the condensate is removed when gravity overcomes pinning forces. In this work, we show rapid condensate transport through cracks that formed due to material shrinkage when a copper tube is coated with silica inverse opal structures. Importantly, the high hydraulic conductivity of the cracks promote axial condensate transport that is beneficial for condensation heat transfer. In our experiments, the cracks improved the heat transfer coefficient from ≈ 12 kW/m2 K for laminar filmwise condensation on smooth clean copper tubes to ≈ 80 kW/m2 K for inverse opal coated copper tubes; nearly a sevenfold increase from filmwise condensation and identical enhancement with state-of-the-art dropwise condensation. Furthermore, our results show that impregnating the porous structure with oil further improves the heat transfer coefficient by an additional 30% to ≈ 103 kW/m2 K. Importantly, compared to the fast-degrading dropwise condensation, the inverse opal coated copper tubes maintained high heat transfer rates when the experiments were repeated > 20 times; each experiment lasting 3–4 h. In addition to the new coating approach, the insights gained from this work present a strategy to minimize oil depletion during condensation from lubricated surfaces.

High-Quality Hexagonal Boron Nitride from 2D Distillation.

The production of high-quality two-dimensional (2D) materials is essential for the ultimate performance of single layers and their hybrids. Hexagonal boron nitride (h-BN) is foreseen to become the key 2D hybrid and packaging material since it is insulating, impermeable, flat, transparent, and chemically inert, though it is difficult to attain in ultimate quality. Here, a scheme is reported for producing single layer h-BN that shows higher quality in view of mosaicity and strain variations than material from chemical vapor deposition (CVD). We delaminate CVD h-BN from Rh(111) and transfer it to a clean metal surface. The twisting angle between BN and the second substrate yields metastable moiré structures. Annealing above 1000 K leads to 2D distillation, i.e., catalyst-assisted BN sublimation from the edges of the transferred layer and subsequent condensation into superior quality h-BN. This provides a way for 2D material production remote from CVD instrumentation.

Facile and low-cost green synthesis of eco-friendly chitosan-silver nanocomposite as novel and promising corrosion inhibitor for mild steel in chilled water circuits

New promising samples of silver nanoparticles: (SNPs)-chitosan (CT) nanocomposite (NC) abbreviated as (SNPs-CTNC) have been synthesized and characterized using the novel green chemistry approach. All the synthesized formulations showed innovative corrosion inhibition for the mild steel samples in the cooling water system. The experimental conditions for the green synthesis of eco-friendly silver nanoparticles (SNPs) using chitosan (CT) biopolymer as both reducing and protecting coating agent for SNPs have been optimized. The synthesis route presented herein was performed by the reduction of silver nitrate (AgNO3) by CT in an autoclave reactor vessel under 1 bar applied pressure at the reaction temperature of 120 °C and various contact time (2, 4, 8, and 16 h) between (AgNO3) and chitosan (CT). The four prepared samples of SNPs-CT NC have been abbreviated in terms of the reaction or the contact time as (2 h, 4 h, 8 h, and 16 h). The four SNPs-CT NC samples were characterized using: UV–Visible spectroscopy; Fourier transform infrared (FTIR); X-ray diffraction (XRD) and transmission electron microscopy (TEM). The SNPs coated by chitosan biopolymer showed good antimicrobial activity, and have extremely fine particle size approaching that of the quantum dots nanoparticles. The particle size distribution of all the prepared nanocomposite samples lies around the nanometer scale range of 3–6 nm. The corrosion rate of the standard corrosion coupons of mild steel in the industrial chilled water in the absence and the presence of different concentrations of SNPs-CTNC samples were measured by the gravimetric method as well as the electrochemical impedance spectroscopy (EIS) and DC-potentiodynamic polarization techniques. The inhibition efficiency (%IE) of SNPs-CTNC achieved up to 97–98% at the concentration of 150 ppm SNPs-CTNC of all the prepared samples (from chemical gravimetric weight loss results). The inhibition efficiency (%IE) of the best performance SNPs-CTNC sample (8 h) showed inhibition efficiency above 80% at 100 ppm (as evident by the further electrochemical techniques: impedance and potentiodynamic polarization results). Both the inhibition efficiency and the antimicrobial activity of SNPs-CT NC samples remained unchanged on aging for twelve months storage where: The percent inhibition efficiency of all SNPs-CTNC samples remain above the percentage of 93% on aging for this relatively long storage time period, the sample 2 h showed the most constant inhibition efficiency (97.6% for the fresh prepared sample and 97.5% for the twelve months aged sample). In addition, the scanning electron (SEM) micrographs have been showed that: A clean and bright metal surface was maintained after the exposure to the chilled water in the presence of SNPs-CTNC along the immersion time of one year. The nanocomposite samples acted by spontaneous physisorption on the metal surface as indicated by the negative value of ΔG°adsorption (equals −18.002 kJ·mol−1). The adsorption data represented in the surface coverage (θ) were found to be linearly fitted well to Langmuir adsorption isotherm with positive and relatively large value of the binding equilibrium constant (K) (43.6) that represented the strong attraction forces between the adsorbed nanocomposite particles and the metal surface. The mode of the adsorption of these nanocomposite particles on the metal surface has been interpreted in terms of the electrostatic interaction between the negatively charged colloidal SNPs and the positively the charged metal surface.