Tin Nanowires Research Articles

Electrocatalytic Performance of Interconnected Self‐Standing Tin Nanowire Network Produced by AAO Template Method for Electrochemical CO2 Reduction**

AbstractIn this study, we used a specially designed aluminum anodic oxide (AAO) template technique to produce interconnected self‐standing tin nanowire electrocatalysts having a high surface‐to‐volume ratio for CO2 reduction toward formate. These electrodes consisted of interconnected tin nanowires with 150 nm diameter and 7 μm length supported on 70–100 μm thick tin film. As prepared electrodes produced 6 times higher formate than the flat tin sheets, yet Faradaic efficiencies (FE%) were unsatisfactory. The main reason for low FE% is determined as the etching of native oxide on tin nanowires during hot alkali treatment to remove AAO and remnant aluminum. Porous anodic oxidation in 1 M NaOH solution was realized to recover tin oxides on the surface. Anodized tin nanowire electrocatalysts produced higher formate than anodized tin sheets, reaching FEformate% of ~87 at −1 V vs. RHE cathodic reduction potential. Moreover, while anodic oxide on flat tin flaked off the surface in 1 h, these electrodes preserved their integrity and formate production ability even after 12 h.

Strong Kinetic-Inductance Kerr Nonlinearity with Titanium Nitride Nanowires

The kinetic inductance of charge carriers in disordered superconductors provides a broadband low-loss source of nonlinear electromagnetic response. This work investigates TiN nanowires as an alternative to Josephson junctions for applications involving elevated temperatures, higher frequencies, and strong magnetic fields. An extreme nanowire geometry for TiN microwave resonators leads to current-density concentration and enhanced self-Kerr coefficient, yielding a nonlinearity-to-loss ratio as high as 21% and quality factor exceeding 10,000. Such devices may find application in quantum frequency conversion of microwave photons, and with improvement might attain strong quantum nonlinearity.

Electron-Stimulated Phase Transitions in Tin and Indium–Tin Nanowires Produced by Laser Ablation in Superfluid Helium

Electron-Stimulated Phase Transitions in Tin and Indium–Tin Nanowires Produced by Laser Ablation in Superfluid Helium

Arrayed Heterostructures of MoS2 Nanosheets Anchored TiN Nanowires as Efficient Pseudocapacitive Anodes for Fiber-Shaped Ammonium-Ion Asymmetric Supercapacitors.

Nonmetallic ammonium ions that feature high safety, low molar mass, and small hydrated radius properties have shown great advantages in wearable aqueous supercapacitors. The construction of high-energy-density flexible ammonium-ion asymmetric supercapacitors (AASCs) is promising but still challenging due to the lack of high-capacitance pseudocapacitive anodes. Herein, freestanding core-shell heterostructures supported on carbon nanotube fibers were designed by anchoring MoS2 nanosheets on nanowires (MoS2@TiN/CNTF) as anodes for AASCs. With contributions of abundant active sites and conspicuous synergistic effects of multiple components for arrayed heterostructure engineering, the developed MoS2@TiN/CNTF anodes exhibit a specific capacitance of 1102.5 mF cm-2 at 2 mA cm-2. Theoretical calculations confirm the dramatic enhancement of the binding strength of ammonium ions on the MoS2 shell layer at the heterostructure, where a built-in electric field exists to accelerate the charge transfer. By utilizing a MnO2/CNTF cathode and NH4Cl/poly(vinyl alcohol) (PVA) as a gel electrolyte, quasi-solid-state fiber-shaped AASCs were successfully constructed, achieving a specific capacitance of 351.2 mF cm-2 and an energy density of 195.1 μWh cm-2, outperforming most recently reported fiber-shaped supercapacitors. This work provides a promising strategy to rationally design heterostructure engineering of MoS2@TiN nanoarrays toward advanced anodes for application in next-generation AASCs.

Heterogeneous Pt-Bi hybrid nanoparticle decorated self-standing hollow TiN nanowire as an efficient catalyst for glycerol electrooxidation

The electrochemical oxidation of glycerol is considered as a promising route to generate high value-added products. Rationally tuning the electronic structure of Pt catalysts by supporter and modifier is desirable for promoting the activity and stability of glycerol electrooxidation reaction (GEOR). In this work, we report Pt–Bi hybrid nanoparticles anchored hollow titanium nitride nanowires grew on carbon cloth (Pt1-x-Bix/TiN HNWs/CC (0≤ x ≤ 1)) as a self-supported monolithic electrode for efficient GEOR. Contributed by 3D porous nanotube structure, high corrosion resistance and conductivity of TiN, and strong electronic coupling effect of Pt, Bi, and TiN, the optimized Pt0.95-Bi0.05/TiN HNWs/CC electrode exhibits good catalytic activity and stability for GEOR. It shows a high peak current density of 88.4 mA cm−2 or 306.7 mA mgPt−1 in 0.05 M glycerol +1.0 M KOH solution. After continuous electrolysis for 8 h in 0.05 M glycerol +1.0 M KOH solution at a constant potential of 0.85 V versus reversible hydrogen electrode (vs. RHE), a high glycerol conversion of 87.0%, a moderate selectivity of 36.6% for glyceric acid, and a good stability were achieved, which is superior to other compared electrodes and most of the reported Pt–Bi catalysts.

Plasmon-enhanced hydrogen evolution on Pt-anchored titanium nitride nanowire arrays

Plasmonic materials integrated with electrochemical catalysts produce hot carriers that improve the catalytic activity of the hydrogen evolution reaction (HER). Previous studies have mainly focused on noble metal-based plasmonic materials. Herein, an efficient catalyst comprising non-noble TiN as the plasmonic booster and Pt nanoparticles (NPs) as the cocatalyst is prepared on carbon cloth (CC) (Pt/TiN/CC) by nitridation of TiO2 in NH3 and electrodeposition. The HER properties are improved significantly as manifested by a small overpotential of 16 mV at a current density of 10 mA cm−2 (η10) as well as 2-fold decay in η10 compared to the control experiment conducted in darkness (33 mV). To investigate the role of light-excited hot electrons in the reduction of protons to H2, Pt/TiOx/CC is irradiated with UV–visible light in the control experiment and the superior characteristics of Pt/TiN/CC corroborate the surface plasmon resonance (SPR) enhancement rendered from the TiN nanowire arrays. This study provides a fundamental understanding of hot electronics generated by SPR and insights into the design of non-noble electrocatalysts for HER and other applications.

A high-performance electrocatalyst composed of nickel clusters encapsulated with a carbon network on TiN nanaowire arrays for the oxygen evolution reaction

Metal cluster catalysts have aroused much interest in the field of electrocatalysis due to high degree of materials utilization and strong substrate interaction, but negative effects such as materials aggregation must be minimized. In this work, rhizobia-like Ni nano-clusters encapsulated with a carbon network are anchored on porous TiN nanowire arrays prepared on carbon cloth (CC) to form a high-performance electrocatalyst for the oxygen evolution reaction (OER) in water splitting. The Ni nano-clusters with a small size and strong interaction with the TiN substrate provide active sites galore to facilitate OER. Furthermore, the skeleton made of porous TiN nanowires on CC provides high electrical conductivity to accelerate charge transport as well as a rough surface to accommodate the Ni nano-clusters. The interaction between the metallic Ni nano-clusters and TiN substrate are demonstrated to promote the activity in OER based on theoretical calculation. This novel electrocatalyst which exhibits superior OER activity and stability in an alkaline electrolyte has large potential in energy conversion and related applications.

Effects of Electrolyte Additives and Nanowire Diameter on the Electrochemical Performance of Lithium‐Ion Battery Anodes based on Interconnected Nickel–Tin Nanowire Networks

Tin‐based nanowire electrodes present desirable properties as lithium‐ion battery anodes, because they undergo volume changes without pulverization. However, they suffer from limited mass loading and propensity for surface parasitic reactions. Herein, the electrochemical performances of nickel–tin 3D‐interconnected nanowire network (NiSn 3DNWN) electrodes are evaluated with the nanowire diameters of 40, 105, and 230 nm, respectively, that attain mass loadings of up to 3 mg cm−2. To mitigate the surface parasitic reactions, the effects of fluoroethylene carbonate (FEC) and vinylene carbonate (VC) additives are investigated as a function of the nanowire diameter and additive concentration. The results show that the FEC and VC of all compositions improve the capacity retentions and coulombic efficiencies (CEs) of the NiSn 3DNWN electrodes. In 10 vol% FEC, the electrodes demonstrate a similar capacity of ≈550 mAh g−1, but the capacity retentions after 100 cycles are 73.68%, 53.79%, and 51.70% for the 40, 105, and 230 nm NiSn 3DNWN, respectively. However, the 105 nm‐diameter nanowire electrode has the highest average CE of 96.55%. Electrochemical impedance spectroscopy and post‐cycling investigations reveal that the FEC has the most profound effect on the interfacial resistances, which is reflected in the rate performances of the tested electrodes.

Cost-effective liquid-junction solar devices with plasma-implanted Ni/TiN/CNF hierarchically structured nanofibers

Carbon-based conductive materials have been recognized as promising alternatives to noble metals as the electrode in optoelectronic devices. Herein, by utilizing energetic plasma ion implantation, Ni-doped TiN nanowire (NWs) modified graphitic carbon nanofibers (CNF) are designed and prepared as the candidates of the platinum (Pt) counter electrode for low-cost hybrid perovskite-based liquid-junction photoelectrochemical solar cells (LPSCs). Notably, the photoelectrochemical (PEC) response of p-Rb0.05FA0.95PbI3 based-LPSCs equipped with the Ni/TiN/CNF counter electrode is almost identical to that with a typical Pt counter electrode. From electrochemical investigations, i.e., electrochemical impedance spectroscopy (EIS), we observe that the CNF-based materials show a similar redox activity compared with the Pt counter electrode, indicating low charge-transfer resistance (Rct) and large capacitance (C). The LPSCs, with a configuration of p-Rb0.05FA0.95PbI3/BQ (2 mM), BQ− (2 mM)/Ni/TiN/CNF-based counter electrode, exhibit an open-circuit photovoltage of 1.00 V and a short-circuit current density of 7.02 mA/cm2 under 100 mW/cm2 irradiation. The overall optical-to-electrical energy conversion efficiency is 5.06%. The PEC solar cell shows good stability for 5 h under irradiation. The CNF-based counter electrode enables potential applications, including but not limited to PEC solar devices, dye-sensitized solar cells (DSSCs), solar fuel devices and hydrogen evolution reaction.

Efficient coupling of MnO2/TiN on carbon cloth positive electrode and Fe2O3/TiN on carbon cloth negative electrode for flexible ultra-fast hybrid supercapacitors.

Recent research and development of energy storage devices has focused on new electrode materials because of the critical effects on the electrochemical properties of supercapacitors. In particular, MnO2 and Fe2O3 have drawn extensive attention because of their low cost, high theoretical specific capacity, environmental friendliness, and natural abundance. In this study, MnO2 ultrathin nanosheet arrays and Fe2O3 nanoparticles are fabricated on TiN nanowires to produce binder-free core–shell positive and negative electrodes for a flexible and ultra-fast hybrid supercapacitor. The MnO2/TiN/CC electrode shows larger pseudocapacitance contributions than MnO2/CC. For example, at a scanning rate of 2 mV s−1, the pseudocapacitance contribution of MnO2/TiN/CC is 87.81% which is nearly 25% bigger than that of MnO2/CC (71.26%). The supercapacitor can withstand a high scanning rate of 5000 mV s−1 in the 2 V window and exhibits a maximum energy density of 71.19 W h kg−1 at a power density of 499.79 W kg−1. Even at 5999.99 W kg−1, it still shows an energy density of 31.3 W h kg−1 and after 10 000 cycles, the device retains 81.16% of the initial specific capacitance. The activation mechanism is explored and explained.

Evaluation of Thermal Expansion Coefficient in Ge1-x Sn x Nanowire Using Reciprocal Space Mapping

We evaluated the thermal expansion coefficients in germanium tin (Ge1 - x Sn x ) nanowire and blanket (un-patterned) film formed on Ge (001) substrate by X-ray diffraction measurement with synchrotron radiation. It was found that the thermal expansion coefficients of Ge0.968Sn0.032 are different in directions between parallel and normal to Ge substrate surface. Effect on anisotropy of lattice parameters on the anisotropic thermal expansion coefficient of Ge0.968Sn0.032 is also clarified, and the largest anisotropy was observed in blanket film.

N-doped carbon-embedded TiN nanowires as a multifunctional separator for Li–S batteries with enhanced rate capability and cycle stability

A 1D titanium nitride with an N-doped carbon composite was developed to suppress polysulfide shuttling and enhance the electrochemical reaction kinetics in Li-S batteries. Lithium-sulfur (Li–S) batteries have attracted considerable attention as next-generation energy storage devices owing to their high theoretical specific capacity and safety. However, the commercialization of Li–S batteries is hindered by critical issues, including the migration of the dissolved lithium polysulfides (LiPSs) from the sulfur electrode to the lithium metal anode, resulting in poor cycling stability. Here, we report a multifunctional interlayer configured with an N-doped carbon framework and titanium nitride nanowires on a polypropylene separator (NC/TiN NWs@PP) to suppress the polysulfide shuttling problem. NC/TiN NWs@PP can be obtained by electrospinning and the subsequent scalable solution-based vacuum filtration. The one-dimensional structure of the TiN NWs can shorten the Li-ion diffusion distance with large electrode/electrolyte interfaces. Furthermore, the N-doped carbon framework in the NWs enables facile electron transportation and allows the suppression of the shuttle effect to improve the electrochemical reaction kinetics. The Li–S battery with a NC/TiN NWs@PP separator exhibited enhanced cycling stability and rate capability, indicating that this could be a new research direction for Li–S batteries.

Interface engineered and surface modulated electrode materials for ultrahigh-energy-density wearable NiCo//Fe batteries

The rational design and construction of high-performance fiber-shaped NiCo//Fe batteries is of great importance for the development of portable and wearable electronics. Electrode materials with all hierarchical core-shell heterostructures have great potential for use in high-performance NiCo//Fe batteries as a result of their good conductivity, high mass loading, and short ion-diffusion paths. Herein is proposed a novel freestanding core-shell positive and negative electrode materials developed by depositing NiCoP nanosheets on nanoflake arrays (NiCoP@NiCoP NFAs) and Fe2O3 nanoneedles on TiN nanowire arrays (TiN@Fe2O3 NWAs) directly grown on carbon nanotube fibers (CNTFs). The fabricated NiCoP@NiCoP NFAs/CNTF was validated to be an ultrahigh capacity cathode (1.07 mAh cm−2 at 2 ​mA ​cm−2), matching well with the similarly constructed TiN@Fe2O3 NWAs/CNTF anode (0.92 mAh cm−2 at 2 ​mA ​cm−2). These electrodes were successfully developed into a high-performance NiCo//Fe battery that exhibited an extraordinary capacity of 0.77 mAh cm−2 and a remarkable energy density of 265.2 ​mWh cm−3. The flexible battery demonstrated an excellent cycling lifespan with 89.4% capacity retention after 4000 cycles. This pioneering study describes a powerful strategy for the rational construction of high-performance electrode materials with hierarchical core-shell heterostructures and constitutes a novel approach for the development of new-generation wearable aqueous rechargeable batteries.

An integrated hybrid interlayer for polysulfides/selenides regulation toward advanced Li–SeS2 batteries

Selenium disulfide (SeS2) is one of the promising cathode materials for high energy density batteries, since it has a competitive theoretical specific capacity (1345 mAh g−1) and much better electrical conductivity over sulfur (S). Similar to S cathode, however, the practical application of SeS2 cathode is also impeded by poor cycling performance caused by the shuttling phenomenon of soluble lithium polysulfides/selenides. In this work, a graphene sponge/titanium nitride (TiN) nanowires composite is prepared as the well-designed multi-functional hybrid interlayer to be applied in Li–SeS2 batteries for the first time. The three-dimensional porous conductive framework constructed by graphene nanoscrolls/nanosheets coexited sponge and TiN nanowires provides efficient transfer channels for electrons and ions. Moreover, TiN not only has strong chemical adsorption to trap the soluble polysulfides/selenides, but also possesses electrocatalytic effects to promote the electrochemical reaction of the cathodic solid-liquid/liquid-solid and the anodic solid-liquid conversions. By virtue of the multi-functional capabilities, the as-assembled cells equipped with the hybrid interlayer exhibit an outstanding electrochemical performance with a long cycling life, a low capacity decay (0.08% per cycle), and superior rate capability (493 mAh g−1 at 5 A g−1). This work offers a new and efficient strategy to propell the development of high-performance Li–SeS2 batteries.

Synthesis of high-performance TiN based battery-type wire supercapacitors and their energy storage mechanisms

Battery-type supercapacitors that exhibit both high power density from capacitor-like behaviour, and high energy density from battery-like behaviour, have attracted significant interest recently. However, compared to conventional capacitor technology, these supercapacitors present new challenges for the design of the electrode materials, since they require not only high conductivity for fast electron transport, but also a suitable crystal structure for efficient ion intercalation. Here, we report a large-capacity wire supercapacitor, which is assembled by forming TiN nanowire arrays on carbonized cotton threads. The resulting structure is capable of both acting as the cathode and the anode, with specific capacities of 12.9 mAh cm−1 and 25.0 mAh cm−1 in Li-ion aqueous electrolyte, respectively. Sweep voltammetry analysis further reveals that the storage characteristics include both battery and capacitor-like behaviour, that is, 50–60% of the energy storage arises from the intercalation/deintercalation of Li/Na ions (battery-like) with the balance coming from the adsorption/desorption of electrolyte ions on the electrode surface (capacitor-like). Finally, two types of wire supercapacitors are assembled (lithium and sodium ion based), which exhibited excellent energy density of 52.5 μW h cm−2 for the lithium ion capacitor and 93.1 μW h cm−2 for the sodium ion capacitor, with 74.9% and 51.5% of the specific capacity retained after 10,000 cycles. This work demonstrates the possible application of these materials and structures in high-performance wearable energy storage systems.

Controlled growth of single-crystalline metal nanowires via thermomigration across a nanoscale junction

Mass transport driven by temperature gradient is commonly seen in fluids. However, here we demonstrate that when drawing a cold nano-tip off a hot solid substrate, thermomigration can be so rampant that it can be exploited for producing single-crystalline aluminum, copper, silver and tin nanowires. This demonstrates that in nanoscale objects, solids can mimic liquids in rapid morphological changes, by virtue of fast surface diffusion across short distances. During uniform growth, a thin neck-shaped ligament containing a grain boundary (GB) usually forms between the hot and the cold ends, sustaining an extremely high temperature gradient that should have driven even larger mass flux, if not counteracted by the relative sluggishness of plating into the GB and the resulting back stress. This GB-containing ligament is quite robust and can adapt to varying drawing directions and velocities, imparting good controllability to the nanowire growth in a manner akin to Czochralski crystal growth.

Defect Engineering of Palladium-Tin Nanowires Enables Efficient Electrocatalysts for Fuel Cell Reactions.

The defect engineering of noble metal nanostructures is of vital importance because it can provide an additional yet advanced tier to further boost catalysis, especially for one-dimensional (1D) noble metal nanostructures with a high surface to bulk ratio and more importantly the ability to engineer the defect along the longitudinal direction of the 1D nanostructures. Herein, for the first time, we report that the defect in 1D noble metal nanostructures is a largely unrevealed yet essential factor in achieving highly active and stable electrocatalysts toward fuel cell reactions. The detailed electrocatalytic results show that the Pd-Sn nanowires (NWs) exhibit interesting defect-dependent performance, in which the defect-rich Pd4Sn wavy NWs display the highest activity and durability for both the methanol oxidation reaction (MOR) and the oxygen reduction reaction (ORR). Density functional theory (DFT) calculations reveal that a large number of surface vacancies/agglomerated voids are the driving forces for forming surface grain boundaries (GBs) within Pd4Sn WNWs. These electronic active GB regions are the key factors in preserving the number of Pd0 sites, which are critical for minimizing the intrinsic site-to-site electron-transfer barriers. Through this defect engineering, the Pd4Sn WNWs ultimately yield highly efficient alkaline ORR and MOR. The present work highlights the importance of defect engineering in boosting the performance of electrocatalysts for potentially practical fuel cells and energy applications.

Precious Metal Free Materials As Efficient Catalysts for Water Splitting

Precious Metal Free Materials as Efficient Catalysts for Water Splitting Pei Kang Shen*, Zhi Qun Tian Collaborative Innovation Center of Sustainable Energy Materials, Guangxi University100 Daxue Road, Nanning 530004, Guangxi, China*E-mail address: pkshen@gxu.edu.cn Water electrolysis is a promising approach for large-scale and sustainable hydrogen production. However, its kinetics is slow and requires precious metal catalysts to efficiently operate. Therefore, great efforts are being undertaken to design and prepare low-cost and highly efficient catalysts to boost the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Currently, we developed different noble metal free materials as efficient catalysts for HER, OER, and full water splitting. For HER, the catalysts with novel nanostructures were prepared, such as carbon-encapsulated WOx (WOx@C), N-doped porous MoN nanobelts, nitrogen and fluorine dual-doped porous graphene-nanosheets, K0.4TaO2.4F0.6 nanocubes, Ni3S2 nanowires, TiN nanowires, nanoflower-like MoO2, et al. For OER catalysts, the Mo- and Fe-modified Ni(OH)2/NiOOH nanosheets, nitrogen-decorated iron-nickel sulfide nanosheets, Mo-doped NiOOH nanosheets, tantalum dioxyfluoride, pristine carbon nanotubes, graphene supported MnO2 nanowires were studied. For full water splitting, the porous WO2 hexahedral networks, heteroatoms dual doped porous graphene nanosheets, three-dimensional porous MoNi4 networks, porous MoO2 nanosheets, dye functionalized carbon nanotubes were studied. The synthesized materials displayed excellent catalytic activity for hydrogen evolution, oxygen evolution, and full water splitting, and can be applied as low cost and highly active multifunctional catalysts with excellent ORR and OER performance. The improved activity and active origin of aforementioned catalysts are clarified through experimental analysis and DFT calculation. These studies pave the way for the design and development of cheaper, highly efficiently and more durable catalysts for wider applications.

Charge control of blockade of Cooper pair tunneling in highly disordered TiN nanowires in an inductive environment

A central problem in understanding the superconductor-insulator transition in disordered superconductors is that the properties of grains and intergrain medium cannot be independently studied. Here we demonstrate an approach to the study of strongly disordered superconducting films by relying on the stochastic nature of the disorder probed by electrostatic gating in a restricted geometry. Charge tuning and magnetotransport measurements in quasihomogeneous TiN nanowires embedded in a superinductor environment allow us to classify different devices and distinguish between spontaneously formed Coulomb islands (with typical blockade voltage in the mV range) and homogeneous wires showing behavior indicative of coherent quantum phase slips (with significantly smaller blockade voltage).

Catalyst-assisted epitaxial growth of ferromagnetic TiO2/TiN nanowires

We report a novel method of growth for single-crystalline TiO2/TiN nanowires through oxidation of epitaxial TiN nanowires on Si-SiO2 (amorphous) and c-sapphire (crystalline) as practical substrates. We propose that the laser ablated Ti and N diffuse into molten Au to form TiN nanodots where the growth rate of nanowires is directly proportional to the laser ablation flux due to high diffusion in molten Au. The TiN nanowires were grown by Pulsed Laser Deposition method using Au as a catalyst. The TiN nanowires were then oxidized to create TiO2/TiN core-shell nanowires. The growth of TiO2 (rutile) occurs by domain matching epitaxy paradigm in such a way that (002) planes of the TiO2 match with (200) plane of TiN, where the TiO2 thickness can be tuned by adjustment of oxidation time and temperature. This design provides a core-shell structure of TiO2/TiN nanowires integrated with silicon and sapphire substrates. The Rutile TiO2 nanowires show ferromagnetic behavior, while the as-grown TiN exhibits diamagnetic behavior. The SEM, TEM, and EBSD are used to characterize the microstructure and atomic alignments of TiO2 nanowires. The simple method of oxidation combined with tunable magnetic properties provides benefits to many smart applications where the magnetic field can be used as an external stimulation.