Sn Nanoparticles Research Articles

A metal-catex composite electrode for determination of paraquat in various samples by Ad-differential pulse cathodic stripping voltammetry

In this work, a novel kind of metal-catex composite electrode for determination of paraquat (PQ) by adsorptive differential pulse voltammetry is introduced. The metal-catex composite electrode was fabricated by cathodic electropolymerization of p-nitrophenol and p-nitrobenzoic acid in the presence of tin (II) chloride as a scaffold for composite structure on prepared glassy carbon electrode. Electropolymerization was carried out in sodium acetate medium. The surface of the fabricated electrode was characterized with field emission scanning electron microscope and energy-dispersive X-ray spectrometry. The obtained results show that there are Sn nanoparticles in the structure of the catex-composite. Chemical structure of metal-catex composite electrode was investigated using FTIR (ATR), 13C NMR, H NMR and a suitable mechanism for electropolymerization has been proposed. This metal-catex composite electrode was applied for determinations of PQ using sodium acetate buffer solutions at pH = 6.5 as an electrolyte solution. All parameters influencing the performance of the fabricated electrode were studied and optimized. The proposed electrode exhibits good linearity versus PQ concentration in the range of 3.8 × 10−8 to 7.7 × 10−7 mol L−1 and shows a manifold increase in sensitivity (more than 30 times) as compared to the glassy carbon electrode. The LOQ of this electrode was 7.78 × 10−9 mol L−1, which is comparable with that of other electrochemical methods. The mean, standard deviation and relative standard deviation for seven repetitive determinations of paraquat (7.78 × 10−8 mol L−1) were measured to be 7.75 × 10−8 mol L−1, ±0.29 × 10−8 mol L−1, and 3.75% respectively. This electrode was applied for the determination of paraquat in natural water, natural juice, potatoes and onions. The introduced electrode shows good stability with repeated use and over long periods (about 20 days). There is a good agreement between the results for water analysis by this method and the standard method.

Ultrahigh and Durable Volumetric Lithium/Sodium Storage Enabled by a Highly Dense Graphene-Encapsulated Nitrogen-Doped Carbon@Sn Compact Monolith.

Tin-based composites hold promise as anodes for high-capacity lithium/sodium-ion batteries (LIBs/SIBs); however, it is necessary to use carbon coated nanosized tin to solve the issues related to large volume changes during electrochemical cycling, thus leading to the low volumetric capacity for tin-based composites due to their low packing density. Herein, we design a highly dense graphene-encapsulated nitrogen-doped carbon@Sn (HD N-C@Sn/G) compact monolith with Sn nanoparticles double-encapsulated by N-C and graphene, which exhibits a high density of 2.6 g cm-3 and a high conductivity of 212 S m-1. The as-obtained HD N-C@Sn/G monolith anode exhibits ultrahigh and durable volumetric lithium/sodium storage. Specifically, it delivers a high volumetric capacity of 2692 mAh cm-3 after 100 cycles at 0.1 A g-1 and an ultralong cycling stability exceeding 1500 cycles at 1.0 A g-1 with only 0.019% capacity decay per cycle in lithium-ion batteries. Besides, in situ TEM and ex situ SEM have revealed that the unique double-encapsulated structure effectively mitigates drastic volume variation of the tin nanoparticles during electrode cycling. Furthermore, the full cell using HD N-C@Sn/G as an anode and LiCoO2 as a cathode displays a superior cycling stability. This work provides a new avenue and deep insight into the design of high-volumetric-capacity alloy-based anodes with ultralong cycle life.

Millimeter-scale laminar graphene matrix by organic molecule confinement reaction

Application of the graphene-based composites in practice was hampered due to the lack of the controllable synthesis strategy. To solve the problem, we envisaged the organic nanodroplets as a nano-reaction environment to obtain the organic nanoframes by photo-polymerization, then to directly graphitize for the graphene-based materials. In such strategy, two-dimensional laminar matrix of graphene nanosheets (2DLMG) was obtained with millimeter-scale surface, which rendered the matrix high electron conductivity. Thanks to the confinement effect of the nanodroplets, the composited materials were homogeneously dispersed in the organic nanoframes. Then, the organic nanoframes converted directly to 2DLMG-based composites after calcination. In this paper, the transformation from organic nanoframes to 2DLMG has been revealed in detail by comprehensive analyses from SEM, XRD and XPS. To demonstrate the versatility of 2DLMG, the superiority in lithium ion battery has been indicated by the high specific capacity (565 mA h g−1), high cycling performance after 500 cycles and the 100% retention capacity in rate measurement. For the synthesis of the composites, Sn nanoparticles and γ-Fe2O3 nanoparticles were distributed in 2DLMG without the aggregation with high loading. The proposed organic molecule confinement reaction strategy was expected to point out a promising direction for the preparation of graphene-based materials.

Li4.4Sn encapsulated in hollow graphene spheres for stable Li metal anodes without dendrite formation for long cycle-life of lithium batteries

Lithium (Li) metal has always faced serious challenges of dendritic growth and low Coulombic efficiency due to the nonuniform electric field distribution and the dynamically changed interface situation. In this paper, the interconnected and closed hollow graphene spheres with an internal load of lithiophilic Li4.4Sn nanoparticles (Li4.4Sn/SG) is prepared to improve Li deposition behavior. Both the density functional theory calculations and experimental studies indicate that Li4.4Sn has higher binding energy and lower nucleation overpotential toward Li than graphene, thus guiding the deposition of Li metal inside the hollow graphene spheres to avoid the generation of uncontrolled Li dendrites and formation of solid electrolyte interface (SEI) on the fresh Li surface. Furthermore, the surface of the non-tip graphene spheres can greatly avoid the uneven distribution of charge caused by the tip effect, so as to continuously guide the uniform deposition of Li on the surface of the spheres after the spheres are completely filled with Li, thus achieving a dense Li metal layer free of dendrites. In consequence, the Li4.4Sn/SG electrode exhibits a long lifespan up to 1000 h and an exceptionally low overpotential (<18 mV). It is believed that the design of the closed hollow spherical structure with lithiophilic nanoparticle seeds inside is a promising strategy to construct high performance Li metal anodes for lithium batteries.

Electrical/thermal behaviors of bimetallic (Ag–Cu, Ag–Sn) nanoparticles for printed electronics

In this work, Ag–Cu and Ag–Sn nanoparticles (NPs) were synthesized by a physical vapor condensation method, i.e. DC arc-discharge plasma. The as-prepared bimetallic NPs consist of metallic cores of Ag–Cu or Ag–Sn and ultrathin oxide shells of CuO or a hybrid of SnO and SnO2. Ag–Sn NPs exhibit a room-temperature resistivity of 4.24 × 10−5 Ω · cm, a little lower than 7.10 × 10−5 Ω · cm of Ag–Cu NPs. Both bimetallic NPs demonstrate typical metallic conduction behavior with a positive temperature coefficient of resistance over 25–300 K. Ag–Sn NPs exhibit thermally competitive stability up to 230 °C and a lower resistivity of 3.18 × 10−5 Ω · cm after sintering at 200 °C, giving it potential for application in flexible printed electronics.

In-situ formation of atomic-level Mn-Sn interfacial compounds for enhanced Li-ion integrated anode

High capacity nanosized SnO2 Li-ion battery anode can realize the reversible conversion of Sn/Li2O to SnO2. However, the coarsening of Sn particles leads to the incompleteness of this reversible reaction and the rapid decay of the reversible capacity. Here, an atom-level Mn–Sn interfacial composite oxide (MnSnO3) is coated on carbon fibers to form an integrated electrode by a simple in-situ technology. Ultrafine Mn nanocrystals can be uniformly dispersed around Sn nanoparticles with synergistic effect, which can effectively inhibit the coarsening of Sn and promote the high reversibility of SnO2 conversion. In addition to the porous nanostructure and binder-free properties, the prepared integrated anode exhibits initial capacity of 1350 mAh g−1 at 0.05 A g−1 with a high Coulombic efficiency of ~77.4%, superior high-rate capability, and stable long-life of more than 1000 cycles. It is hoped that this design will provide a new idea for the development of high-performance SnO2-based anodes.

Carbon supported Pd–Sn nanoparticle eletrocatalysts for efficient borohydride electrooxidation

Carbon supported Pd–Sn (Pd–Sn/C) nanoparticle electrocatalysts are prepared via a facile and environmentally friendly method and successfully applied in BH4− electrooxidation.

High-performance alcohol electrooxidation on Pt3Sn–SnO2 nanocatalysts synthesized through the transformation of Pt–Sn nanoparticles

An ordered Pt3Sn intermetallic, in which every Pt3Sn NP is in contact with one or more SnO2 NPs, was synthesized by the in situ transformation of Pt–Sn/NG.

In situ TEM observation of liquid-state Sn nanoparticles vanishing in a SiO2 structure: a potential synthetic tool for controllable morphology evolution from core-shell to yolk-shell and hollow structures.

Precise design of hollow nanostructures can be realized via various approaches developed in the last two decades, endowing nanomaterials with unique structures and outstanding performances, showing their usefulness in a broad range of fields. Herein, we demonstrate the formation of SnO2@SiO2 hollow nanostructures, for the first time, by interaction between liquid state Sn cores and SiO2 shell structures inside Sn@SiO2 core–shell nanoparticles with real-time observation via in situ transmission electron microscopy (TEM). Based on the in situ results, designed transformation of the nanoparticle structure from core–shell Sn@SiO2 to yolk–shell Sn@SiO2 and hollow SnO2@SiO2 is demonstrated, showing the controllable structure of core–shell Sn@SiO2 nanoparticles via fixing liquid-state Sn inside a SiO2 shell which has a certain Sn containing capacity. The present approach expands the toolbox for the design and preparation of yolk–shell and hollow nanostructures, thus providing us with a new strategy for fabrication of more complicated nanostructures.

Growth of an Al2O3 Layer and Sn@Al2O3 Core-Shell Nanoparticles by Using a Silicon Oxide/Aluminum Bilayer

An alternative method for the fabrication of an aluminum oxide (Al2O3) layer was employed to produce Sn@Al2O3 core-shell nanoparticles (NPs). The Al2O3 layer was formed by low-temperature annealing of the bilayer silicon-rich oxide (SiOx)/aluminum (Al) structure. The resulting Al2O3 layer was found to have a polycrystalline structure, in which the crystallites exhibited a γ-Al2O3 phase. Based on this method, a Sn@Al2O3 core-shell NP layer was formed between the tunneling and the control SiO2 layers, providing a Sn NP floating gate with a SiO2/Al2O3 dielectric stacked tunneling barrier. Capacitance-voltage measurements on this structure confirmed high charge storage characteristics, thereby rendering this material suitable for use in stable memory device applications.

Sn addition effect on magnetic reversibility of Co–Ni alloy nanoparticles based on the FORC results

Ternary Co–Ni–Sn nanoparticles were prepared using a chemical polyol method, and their magnetic and structural properties were investigated by a vibrating sample magnetometer (VSM), first-order reversal curve (FORC), X-ray diffraction and scanning electron microscopy (SEM). It was found that, by increasing the amount of Sn, the magnetization of the synthesized samples decreased from 65 to 34 emu/g. In addition, the XRD patterns of low Sn concentration samples showed the presence of both CoNi and Sn structures along with a trace of cobalt oxide. However, the crystallinity of the resulting samples decreased to an amorphous state. According to the results of FORC analysis, the soft and hard magnetic phases were completely separated and the percentage of reversibility was reduced due to the increased Sn concentration, so that the percentages of the reversibility and irreversibility were equal in the samples with the highest concentration of Sn. From SEM images, the change in the amount of constituents leads to a morphological variation from spherical-shaped to sheet-like particles.

SnO2 as Advanced Anode of Alkali‐Ion Batteries: Inhibiting Sn Coarsening by Crafting Robust Physical Barriers, Void Boundaries, and Heterophase Interfaces for Superior Electrochemical Reaction Reversibility

AbstractSuperior reaction reversibility of electrode materials is urgently pursued for improving the energy density and lifespan of batteries. Tin dioxide (SnO2) is a promising anode material for alkali‐ion batteries, having a high theoretical lithium storage capacity of 1494 mAh g− based on the reactions of SnO2 + 4Li+ + 4e− ↔ Sn + 2Li2O and Sn + 4.4Li+ + 4.4e− ↔ Li4.4Sn. The coarsening of Sn nanoparticles into large particles induced reaction reversibility degradation has been demonstrated as the essential failure mechanism of SnO2 electrodes. Here, three key strategies for inhibiting Sn coarsening to enhance the reaction reversibility of SnO2 are presented. First, encapsulating SnO2 nanoparticles in physical barriers of carbonaceous materials, conductive polymers or inorganic materials can robustly prevent Sn coarsening among the wrapped SnO2 nanoparticles. Second, constructing hierarchical, porous or hollow structured SnO2 particles with stable void boundaries can hinder Sn coarsening between the void‐divided SnO2 subunits. Third, fabricating SnO2‐based heterogeneous composites consisting of metals, metal oxides or metal sulfides can introduce abundant heterophase interfaces in cycled electrodes that impede Sn coarsening among the isolated SnO2 crystalline domains. Finally, a perspective on the future prospect of the structural/compositional designs of SnO2 as anode of alkali‐ion batteries is highlighted.

Effective Magnetic Field Regulation of the Radical Pair Spin States in Electrocatalytic CO2 Reduction.

Regulation of the radical pair spin states allows effective optimization of the electrocatalytic CO2 reduction reaction. This study for the first time reports an experimental observation of significantly boosting the catalytic activity of tin nanoparticle catalysts by an external magnetic field for electrocatalytic CO2 reduction to formate/formic acid. We reveal that enhancing the amount of singlet radical pairs via magnetic field-facilitated triplet → singlet spin evolution can significantly increase the catalytic activity toward an efficient overall electrochemical CO2 reduction reaction. When a common Sn nanoparticle electrode was used as an example, in a constant applied magnetic field (about 0.9 T), the yield of formic acid can be nearly doubled compared to that of zero magnetic field. This finding suggests the merits of radical pair spin states in the electron-transfer process and paves the way toward high formate production in electrocatalytic reduction of CO2.

Lithium-assisted creep deformation behavior of Sn nanoparticle electrode with fracture-resistant ability

Abstract

Soldering of Passive Components Using Sn Nanoparticle Reinforced Solder Paste: Influence on Microstructure and Joint Strength.

In this study, the effects of adding Sn nanopowder (particle size < 150 nm) to three solder pastes SAC3-X(H)F3+, SCAN-Ge071-XF3+, and water washable WW50-SAC3 are evaluated regarding microstructure, morphology, joint strength, and electrical resistance. The nanopowder was added at a rate of 10% by weight and then mechanically mixed until homogenous solder paste was obtained. The results showed that the addition of Sn nanoparticles resulted in homogenous bond formation for SAC-3 and SCAN, while voids and bubbles formation slightly increased within the joint interface for the water washable solder paste. The SCAN + Sn nano reinforced solder paste showed increased variation of joint strength from 12.6 to 39.9 N, while the water washable + Sn nanopowder reinforced solder paste showed less variability in joint strength from 17.3 to 33.9 N. Both sets of solder paste with and without Sn nano reinforced solder paste showed a reliable quality joint under mechanical shock testing after six shocks in six milliseconds with an 87.1 ms pulse duration. The results showed that Sn nanoparticles resulted in a small resistance change, while RDC values (in mΩ) slightly decreased for SAC and increased for SCAN and further increases for water washable solder paste.

Development of a Novel Tyrosinase Amperometric Biosensor Based on Tin Nanoparticles for the Detection of Bisphenol A (4.4-Isopropylidenediphenol) in Water

Highly crystalline poly-vinyl pyrrolidone (PVP) capped Sn nanocrystals with good size and shape uniformity was synthesized by a hydrothermal process. A highly sensitive amperometric biosensor for the detection of Bisphenol A (BPA) was developed by immobilizing Tyrosinase on to glassy carbon electrode (GCE) modified with Sn nanoparticles. The fabricated amperometric biosensor exhibited excellent electroactivity towards BPA oxidation catalysed by enzymatic reaction of tyrosinase together with good conductivity of Sn nanoparticles. The developed biosensor displayed linear range from 0.01 to 0.10 μmol L-1 and a detection limit (DL) of 1.8 nmol L-1 with a correlation coefficient of 0.989. Electrochemical impedance spectroscopy (EIS) obtained in buffer solution for Tyrosinase/SnNP/GCE had the lowest charge transfer resistance (Rct) value of 219 Ω, which indicated low charge transfer. There was an increase in Rct for Tyrosinase/GCE, SnNP/GCE and Bare GCE which was 316 Ω, 638 Ω and 598 Ω respectively. This indicated a strong resistance to charge transfer. It is reported for the first time the use of Sn nanoparticles modified on GCE and tyrosinase for detection of BPA.

Silicon Oxycarbide: Silicon Oxycarbide—Tin Nanocomposite as a High‐Power‐Density Anode for Li‐Ion Batteries (Adv. Sci. 19/2019)

In article number 1901220, Thomas Graule, Maksym V. Kovalenko, and co-workers present a new synthesis of Sn nanoparticles (NPs) embedded in a SiOC matrix via the pyrolysis of a preceramic polymer as a single-source precursor. This approach yields a homogeneous dispersion of Sn NPs in a SiOC matrix, which helps to buffer the volume changes of Sn and prevent particle aggregation upon lithiation/delithiation.

Fabrication of Sn@Al2O3 Core-shell Nanoparticles for Stable Nonvolatile Memory Applications.

Sn@Al2O3 core-shell nanoparticles (NPs) with narrow spatial distributions were synthesized in silicon dioxide (SiO2). These Sn@Al2O3 core-shell NPs were self-assembled by thermally annealing a stacked structure of SiOx/Al/Sn/Al/SiOx sandwiched between two SiO2 layers at low temperatures. The resultant structure provided a well-defined Sn NP floating gate with a SiO2/Al2O3 dielectric stacked tunneling barrier. Capacitance-voltage (C-V) measurements on a metal-oxide-semiconductor (MOS) capacitor with a Sn@Al2O3 core-shell NP floating gate confirmed an ultra-high charge storage stability, and the multiple trapping of electron at the NPs, as expected from low-k/high-k dielectric stacked tunneling layers and metallic NPs, respectively.

Graphitic N-CMK3 pores filled with SnO2 nanoparticles as an ultrastable anode for rechargeable Li-ion batteries

The incorporation of ultrafine SnO2 particles inside N-doped ordered mesoporous carbon (N-CMK3) is suggested as a method to prepare an ultrastable anode material for Li-ion batteries. Sn nanoparticles formed by chemical reduction of SnCl4 inside N-CMK3 pores are spontaneously reoxidised by dissolved oxygen, resulting in the formation of ultrafine SnO2 inside N-CMK3 pores. This SnO2@N-CMK3 exhibits superior capacity, cyclability, and rate capability. Over 100 cycles at a rate of 0.1C, SnO2@N-CMK3 maintains a specific capacity of 635 mAh g−1, corresponding to a capacity retention of 86.6%. Over 1000 cycles at the rate of 0.5C, SnO2@N-CMK3 can deliver a capacity of 433 mAh g−1. At an ultrahigh rate of 5C, SnO2@N-CMK3 still delivers a capacity higher than that of commercial graphite. The full cell, composed of an SnO2@N-CMK3 anode, LiCoO2 cathode, and sacrificial Li electrode, presents excellent performance, better than previous reports of Li-ion cells. By employing a sacrificial Li electrode, the issue related to the low Coulombic efficiency of SnO2@N-CMK3 in the first few cycles and the pre-lithiation SnO2@N-CMK3 electrode can be successfully addressed.

Sn nanoparticles anchored on N doped porous carbon as an anode for potassium ion batteries

Owing to the rich abundance and low-cost of K resources, potassium-ion batteries (KIBs) have been a promising alternative to lithium-ion batteries (LIBs). The exploration of suitable anode materials is challenging but of great importance for KIBs development. Alloying anodes such as Sn, Sb and their oxides have been proved as promising anode materials for KIBs due to their high specific capacities. Here, Sn nanoparticles uniformly anchored on N doped porous carbon (Sn/NPC) are prepared using simple sol-gel method and heat treatment. As support skeleton, NPC endows Sn/NPC good conductivity and prevent agglomeration of Sn nanoparticles, which can be beneficial for high capability and rate performance. When evaluated as anode of KIBs, enhanced capacity of 198 mAh g−1 is achieved at a current density of 50 mA g−1 after 200 cycles.