Study Of Interfacial Reactions Research Articles

In situ surface-enhanced Raman spectroscopy study of interfacial catalytic reaction of bifunctional metal nanoparticles

In situ surface-enhanced Raman spectroscopy study of interfacial catalytic reaction of bifunctional metal nanoparticles

Systematic Study of Liquid-State Interfacial Reactions Between Co and In-Sn Solders with Varying Sn Contents

Systematic Study of Liquid-State Interfacial Reactions Between Co and In-Sn Solders with Varying Sn Contents

Modeling Interfacial Proton-Coupled Electron Transfer Reactions Involving Imidazolium Proton Donors

Proton-coupled electron transfer (PCET) is an elementary reaction that plays a pivotal role in various electrochemical energy conversion and storage processes. PCET reactions involving nonaqueous proton donors are of interest for applications in energy storage such as redox flow batteries, as well as in CO2 and O2 reduction catalysis. Yet, there remains much to be understood about the molecular reactivity of these systems. In this talk, I will describe periodic density functional theory (DFT) studies of interfacial PCET reactions involving different imidazolium proton donors on Pt(111) electrode surfaces.The imidazole conjugate bases adsorb strongly to the electrode surface; however, this adsorption behavior varies with isomers that feature distinct proton positions and with different functional substituent groups. Because the adsorption of imidazole conjugate bases could affect reactivity, these models are used as a foundation to understand the intrinsic PCET kinetics of these systems. The Volmer and Heyrovsky steps of hydrogen evolution reaction are two of the most basic heterogeneous electrochemical PCET reactions and are therefore chosen as model interfacial PCET reactions in this study. Potential-dependent reaction energies and activation barriers are calculated using the charge extrapolation method, where the electrode potential is tuned by modifying proton coverage for different-sized unit cells. This approach is used to develop relationships between PCET reaction thermodynamics and kinetics through Brønsted–Evans–Polanyi (BEP) relationships for different imidazoles, where BEP slopes are analogs to charge transfer coefficients in the Butler–Volmer equation. Investigating reaction parameters influencing charge transfer kinetics at the electrode-electrolyte interface is crucial for designing efficient energy storage systems, impacting overall device performance. These studies show trends in the kinetic behavior of different functionalized imidazoles, which can aid in the design of catalytic and energy storage systems.

Nicotiana alkaloids-intervened phospholipid ozonolysis at the air-water interface

Cigarette nicotiana alkaloids associated with lung and cardiovascular diseases attack enormous attention. However, the mechanism at the molecular level between nicotiana alkaloids and phospholipid ozonolysis remains elusive. Herein, we investigated the interfacial ozonolysis of a hung droplet containing 1-palmitoyl-2-oleoyl-sn-phosphatidylglycerol (POPG) intervened by nicotiana alkaloids (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, NNK; rac-N′-nitrosonornicotine, NNN; nicotine; and (R,S)-N-nitrosoanasabine, NAT) and followed by on-line mass spectrometry analysis. NNK and NNN showed an acceleration on the interfacial ozonolysis, while nicotine and NAT inhibited this chemistry. Such acceleration/inhibition on POPG ozonolysis was positively correlated with nicotiana alkaloid concentrations. The reaction rate constants suggested that the ozonolysis of lung phospholipids exposed to cigarette smoke at the air-water interface occurred rapidly. A possible mechanism of the hydrophilic/oleophilic nature of nicotiana alkaloids mediating the packing density of POPG was proposed. NNK and NNN with a hydrophilic nature inserted into the POPG monolayer loosed the packing, but nicotine and NAT with an oleophilic nature let the POPG closely pack and shield the CC double bonds exposed to ozone (O3). These results gain the knowledge of nicotiana alkaloids mediated phospholipid ozonolysis at the molecule level and provide a method for online interfacial reaction studies associated with elevated indoor pollutants on public health.

Revealing the surface-to-bulk degradation mechanism of nickel-rich cathode in sulfide all-solid-state batteries

Layered nickel-rich materials (LiNi1-y-zCoyMnzO2, 1–y–z ≥ 0.8) are regarded as promising cathode candidates for all-solid-state batteries (ASSBs); however, nickel-rich cathodes exhibit low Coulombic efficiency and poor cycle stability at high cutoff potentials (E ≥ 4.2 V vs. Li+/Li). To interpret this, much attention has been focused on the study of interface reactions, while ignoring the bulk structure evolution of active materials during cycling. Herein, we thoroughly investigate the bulk structure evolution of single-crystal LiNi0.8Co0.1Mn0.1O2 in ASSBs at different cycles, further correlated with its interface reactions and electrochemical performance. Operando X-ray diffraction detects the emergence of sluggish phase in ASSBs during the first charge process, which accumulates significantly as the cycle progresses, corresponding to the limited delithiation and rapid performance decay. Our results reveal that the surface chemistry has a great effect on the bulk structure evolution and such a surface-to-bulk degradation mechanism is critical to the cathode design toward high-performance ASSBs. From this novel perspective, we demonstrate that the enhanced performance employing the surface coating on the nickel-rich materials is attributed not only to the suppression of interfacial side reactions but also to the elimination of sluggish phase.

Study of interface reaction in a B4C/Cr mirror at elevated temperature using soft X-ray reflectivity.

Boron carbide is a prominent material for high-brilliance synchrotron optics as it remains stable up to very high temperatures. The present study shows a significant change taking place at 550°C in the buried interface region formed between the Cr adhesive layer and the native oxide layer present on the silicon substrate. An in situ annealing study is carried out at the Indus-1 Reflectivity beamline from room temperature to 550°C (100°C steps). The studied sample is a mirror-like boron carbide thin film of 400 Å thickness deposited with an adhesive layer of 20 Å Cr on a silicon substrate. The corresponding changes in the film structure are recorded using angle-dependent soft X-ray reflectivity measurements carried out in the region of the boron K-edge after each annealing temperature. Analyses performed using the Parratt recursive formalism reveal that the top boron carbide layer remains intact but interface reactions take place in the buried Cr-SiO2 region. After 300°C the Cr layer diffuses towards the substrate. At higher temperatures of 500°C and 550°C the Cr reacts with the native oxide layer and tends to form a low-density compound of chromium oxysilicide (CrSiOx). Depth profiling of Si and Cr distributions obtained from secondary ion mass spectroscopy measurements corroborate the layer model obtained from the soft X-ray reflectivity analyses. Details of the interface reaction taking place near the substrate region of boron carbide/Cr sample are discussed.

Comparative study of interfacial reaction and bonding property of laser- and reflow-soldered Sn–Ag–Cu/Cu joints

Comparative study of interfacial reaction and bonding property of laser- and reflow-soldered Sn–Ag–Cu/Cu joints

Advances in studying interfacial reactions in rechargeable batteries by photoelectron spectroscopy

X-ray photoelectron spectroscopy is a key characterisation technique in the study of interfacial reactions within modern rechargeable batteries.

First-principles calculation of diamond/Al interface properties and study of interface reaction

First-principles calculation and experimental methods are used to study the interfacial properties and reaction of diamond/Al composites. Based on the first-principles method, the interfacial adhesion work (<i>W</i><sub>ad</sub>), electronic structure and charge transfer of diamond/Al models are calculated systematically. The results show that the adhesion work of diamond(100)/Al(111) is 41% higher than that of diamond(111)/Al(111), therefore, the interface bonding of diamond(100)/Al(111) interface is stronger. According to the analysis of the electronic structure, there are more charges transferring at the diamond(100)/Al(111) interface, and the high charge density is distributed on the side of C atoms. The redistribution of charges at the interface is conducive to the formation of Al—C bond, so that the tendency of forming Al—C bonds is greater. The introduction of Al—C bond can promote the formation of C—C bond at the diamond(100)/Al(111) interface and improve the interfacial adhesion work. In addition, the diamond/Al composites are fabricated by vacuum gas pressure infiltration, and multi-scale characterization of the interface structure of diamond/Al composites is carried out. The interfacial debonding occurs mainly on the diamond {111}. Meanwhile, the interface product Al<sub>4</sub>C<sub>3</sub> is easier to form on the diamond {100}. The experimental phenomenon is consistent with the calculated results. Moreover, the influence of the interfacial reaction on the properties and stability of diamond/Al composites are further discussed through heat-moisture treatment. The study finds that the performance degradation in heat-moisture environment is related mainly to the hydrolysis of the interface product Al<sub>4</sub>C<sub>3</sub>. After 60 days’ heat-moisture, the thermal conductivity of the diamond/Al composites decreases by 29.9%, and the bending strength is reduced by 40.1%. The large attenuation of performance is not conducive to the stability of composites in complex environments. Therefore, inhibiting the formation of Al<sub>4</sub>C<sub>3</sub> and improving interfacial selectivity are of great importance in developing the performance and stability of diamond/Al composites. The research in this paper not only lays a theoretical foundation for the first-principles calculation of the interface properties of diamond/metal, but also possesses important guidance significance in designing the diamond/metal composites.

The Study of Interfacial Reaction between SnAgCu (SAC) Lead-free Solder Alloys and Copper Substrate: A Short Review

This paper is aimed to review and study the interfacial reaction between SnAgCu (SAC) lead-free solder alloys and common copper substrates. Among the lead-free solders, a ternary solder alloys, SnAgCu (SAC) based solder, is leading the lead-free solders as it has excellent thermal and electrical properties. The interfacial between solder alloy and substrate comprise an important characteristic in the reliability performance of a solder alloy. As the current industry has driven to miniaturization, high integration and multifunctionality, the reliability and durability of solder joints are gained attention for its long-term performance of electronic products. Therefore, in this short review, the interfacial reaction between SAC solder alloys and copper substrate will be focused. Besides, the effects of the addition of microalloying elements into SAC solder alloys will be discussed.

How lithium dendrites form in liquid batteries.

Studies of interfacial reactions and mass transport may allow safe use of lithium metal anodes

Enhancing the High-Voltage Cycling Stability of Nickel-Rich Oxide Cathode Using Functional Electrolyte

Increasing needs of electric vehicles and grid-based energy storage systems for the reduction of carbon dioxide gases require higher energy density lithium (Li)-ion batteries than commercial batteries. The energy density of Li-ion batteries can increase by increasing the specific capacity of cathode material, which can increase by raising the charge cut-off voltage. Among various cathode materials, nickel-rich layered oxides of Li(Ni1 –x –y Co x Mn y )O2 (NCM, 1–x–y ≥ 0.5) are promising high-capacity cathode materials for high-energy density Li-ion batteries because of higher capacity and lower cost than nickel-lean oxides. However, the limited anodic instability of the conventional carbonate-based organic electrolytes at the voltage higher than 4.2 V versus Li/Li+ and instability of cathode-electrolyte interface at highly charged state makes high-voltage charge of nickel-rich oxide cathode difficult. In order to mitigate the electrolyte and interface issues, we have been developing new functional electrolytes that provides high anodic stability above 4.3 V and highly stable cathode-electrolyte interface. High-voltage electrochemical and interfacial reaction studies and their correlation to cycling performance would be discussed in the meeting. Acknowledgements: This research was supported by Ministry of Trade, Industry & Energy (R0004645) and Creative Human Resource Development Consortium for Fusion Technology of Functional Chemical/Bio Materials of BK Plus program by Ministry of Education of Korea.

Initial interfacial reactions of Ag/In/Ag and Au/In/Au joints during transient liquid phase bonding

A comparative study of initial interfacial reactions and kinetics of AgIn and AuIn as die-attach materials for high-temperature power electronics applications was performed in this study. Sequential interfacial reactions and transformations of the In solder to intermetallic compound (IMC) phases of the Ag/In/Ag and Au/In/Au joints were investigated and compared for transient liquid phase (TLP) bonding at 190 °C for 1 min under different bonding pressures. The interfacial reaction of the Ag/In/Ag joint was faster than that of the Au/In/Au joint under same bonding conditions. In the Ag/In/Ag joints, the TLP joint was fully converted into the Ag-rich Ag2In IMC. On the other hand, the Au/In/Au TLP joint was composed of three AuIn IMCs of Au7In3, AuIn, and AuIn2.

Study of Interfacial Reactions Between Lead-Free Solders and Cu-xZn Alloys

The solid/liquid reaction couple technique was employed to investigate the interfacial reactions between Cu-xZn (x = 0 wt.%, 5 wt.%, 15 wt.%, 30 wt.%, 40 wt.%) alloys and lead-free solders Sn, Sn-3.0Ag-0.5Cu (SAC, in wt.%), and Sn-9Zn (SZ, in wt.%) alloys at 240°C, 270°C, and 300°C for 0.5 h to 100 h. (Cu,Zn)6Sn5 and (Cu,Zn)3Sn phases were formed in the Sn/Cu-xZn (x = 5 wt.%, 15 wt.%, 30 wt.%) reaction couples, but with increasing reaction temperature and time, (Cu,Sn)Zn phase was formed, replacing (Cu,Zn)3Sn phase. Metastable T phase and (Cu,Sn)Zn phase were formed in the Sn/Cu-40Zn reaction couple at 300°C. (Cu,Zn)6Sn5 and (Cu,Zn)3Sn phases formed in the SAC/Cu-xZn (x = 5 wt.%, 15 wt.%) reaction couples. Furthermore, (Cu,Zn)6Sn5 and (Cu,Zn)Sn phases were observed when the SAC solders reacted with Cu-30Zn and Cu-40Zn alloys. T phase and (Cu,Sn)Zn phase were formed in the SAC/Cu-40Zn reaction couple reacted at 300°C for 100 h. (Cu,Sn)Zn5 and (Cu,Sn)5Zn8 phases were formed in the SZ/Cu-Zn reaction couples at 240°C. However, with increasing reaction time and temperature, only (Cu,Sn)5Zn8 phase was detected. Therefore, it can be concluded that the intermetallic compound (IMC) formation was sensitive to both the reaction temperature and the Zn content in the Cu-Zn alloy.

Kinetic study of solid-state interfacial reactions of p-type (Bi,Sb)2Te3 thermoelectric materials with Sn and Sn–Ag–Cu solders

P-type (Bi,Sb)2Te3 material system is extensively used in commercial thermoelectric (TE) applications. Soldering is commonly applied to fabricate bulk TE elements into TE modules. This study carefully examined the solid-state interfacial reactions of the commercial (Bi,Sb)2Te3 substrate with Sn and Sn–3.0Ag–0.5Cu solders. The joining plane was along the c-axis of the highly oriented [1 1 0] TE substrate. For the reactions with pure Sn solder, both the intermetallic compounds (IMCs) of SnTe and SnSb were rapidly formed at the interface. Most importantly, it was clearly demonstrated that both of them exhibited a linear growth with the aging time. The growth rates of SnTe and SnSb were 15.1 μm/h and 4.3 μm/h, respectively, at 180 °C. The IMC growth kinetics was further investigated systematically. The activation energies for the SnTe and SnSb growths were 151.6 kJ/mol and 165.3 kJ/mol, respectively. For the Sn–3.0Ag–0.5Cu/(Bi,Sb)2Te3 reaction, the SnTe and SnSb were also formed simultaneously. Similarly, they also had a linear growth, but their growth rates were significantly suppressed. A thin stripe-like Ag-rich phase was formed at the SnTe/(Bi,Sb)2Te3 interface, which could be the cause of the suppression of IMC growth. Additionally, minor addition of 0.1 wt.% Ga in Sn was also found to effectively suppress the interfacial IMC growth.

Interfacial reaction and microstructure study of DSS/Cu/Ti64 diffusion-welded couple

In the present study, the interfacial reaction and microstructure behavior of diffusion-welded joints (DWJs) between duplex stainless steel (DSS) and Ti–6Al–4V alloy (Ti64) with copper interlayer were investigated. The joints were carried out at 825, 850, 875 and 900 °C temperature for 60 min under 4 MPa uniaxial pressure in vacuum. Welded joint was characterized by light microscopy and scanning electron microscopy using backscattered electron mode. Layer-wise Cu4Ti, Cu2Ti, Cu4Ti3, CuTi and CuTi2 intermetallic phases were formed at the Cu–Ti64 interface and the width of the intermetallic layers increases with increase in welding temperature. However, the DSS–Cu interface was completely free from intermetallics. The activation energy and interfacial energy of reaction phases was calculated at the interface. The activation energy values showed that the CuTi intermetallic grew faster than the other phases of the Cu–Ti-based reaction. However, CuTi2 phase first nucleates than the other Cu–Ti-based intermetallics due to its lowest interfacial energy. The highest joint tensile strength of ~ 516 MPa (~ 79% of DSS) along with ~ 6.6% ductility was achieved at 875 °C processing temperature.

Integrated plasmon-enhanced Raman scattering (iPERS) spectroscopy

A new strategy named integrated plasmon-enhanced Raman scattering (iPERS) spectroscopy that features a configuration of evanescent field excitation and inverted collection is presented, which well unites the local field enhancement and far field emission, couples localized and propagating surface plasmons, integrates the SERS substrates and Raman spectrometers via a self-designed aplanatic solid immersion lens. A metallic nanoparticle-on-a film (NOF) system was adopted in this configuration because it improves the amplification of the incidence light field in near field by 10 orders of magnitude due to the simultaneous excitation of quadrupolar and dipolar resonance modes. This iPERS allows for higher excitation efficiency to probed molecules and full collection of the directional-radiation Raman scattering signal in an inverted way, which exhibits a practical possibility to monitor plasmonic photocatalytic reactions in nanoscale and a bright future on interfacial reaction studies.

In-situ mass-electrochemical study of surface redox potential and interfacial chemical reactions of Li(Na)FePO4 nanocrystals for Li(Na)-ion batteries

In this work, an in-situ experimental mass-electrochemical investigation of the LiFePO4 (LFP) and NaFePO4 (NFP)electrolyte interfacial chemical reactions and surface redox potential is achieved by adopting electrochemical quartz crystal microbalance (EQCM) to monitor the mass change trend. In organic electrolyte, LFP (NFP) cathode's mass decreases/increases during the charge/discharge process because of deintercalation/intercalation of Li (Na) ions, which is an normal phenomenon which is generally known. However, the mass-potential curve for LFP nanocrystals in aqueous electrolyte show an anomalous mass change interval (AMCI) around 3.42V (vs. Li/Li+) where the cathode's mass increase in the charging process and mass decrease in the discharging process, which doesn’t obey the normal law of mass change. Through density functional theory (DFT) calculations, we gain a microscopic picture of the solid-liquid interface structure with a reconstructed LFP (010)/H2O and NFP (010)/H2O interface. Taken together, it's concluded that the surface redox potential of LFP is around 3.31V, which is lower than the bulk potential (3.42V) and the desolvation/solvation rate of surficial Li-ion is lower than the bulk Li-ion diffusion rate. While for NFP, it's surface redox potential is almost the same as the bulk one.

Systematic study of interfacial reactions induced by metal electrodes in high-k/InGaAs gate stacks

We systematically studied the effects of metal electrodes on high-k/InGaAs gate stacks and observed that the remote reactions—both oxidation and reduction—at the interface between the high-k dielectrics and InGaAs were thermodynamically initiated by the metal electrodes. Metal electrodes with negative Gibbs free energies (e.g., Pd) resulted in the oxidation of the InGaAs surface during the forming-gas annealing. In contrast, with TiN electrodes, which have a positive Gibbs free energy, the native III–V oxides underwent the reduction between the high-k dielectrics and InGaAs. We demonstrated that the reduction of native III–V oxides by metal electrodes improved the interface quality of the high-k/InGaAs gate stacks and produced an interface trap density (Dit) at the mid-gap with a value as low as 5.2 × 1011 cm−2 eV−1 with a scaled capacitance-equivalent thickness.

Computational Studies of Interfacial Reactions at Anode Materials: Initial Stages of the Solid-Electrolyte-Interphase Layer Formation

Understanding interfacial phenomena such as ion and electron transport at dynamic interfaces is crucial for revolutionizing the development of materials and devices for energy-related applications. Moreover, advances in this field would enhance the progress of related electrochemical interfacial problems in biology, medicine, electronics, and photonics, among others. Although significant progress is taking place through in situ experimentation, modeling has emerged as the ideal complement to investigate details at the electronic and atomistic levels, which are more difficult or impossible to be captured with current experimental techniques. Among the most important interfacial phenomena, side reactions occurring at the surface of the negative electrodes of Li-ion batteries, due to the electrochemical instability of the electrolyte, result in the formation of a solid-electrolyte interphase layer (SEI). In this work, we briefly review the main mechanisms associated with SEI reduction reactions of aprotic organic solvents studied by quantum mechanical methods. We then report the results of a Kinetic Monte Carlo method to understand the initial stages of SEI growth.