Ionic Layer Research Articles

Phenyl-C61-butyric acid methyl ester (PCBM) Nanoparticle Mediated Boasting of Photoelectrochemical and Photocatalytic Properties of Bismuth Vanadate/lead sulphide (BiVO4/PbS) Composite Thin-Film

This work delineates the fabrication and characterization of BiVO4/PbS and BiVO4/PCBM/PbS-based composite heterostructure for visible-light-driven applications, such as pollution remediation, photoelectrochemistry (PEC), and applied bias to photoelectrochemical hydrogen generation efficiency (ABPE). The heterostructured composite was synthesized by a combination of Spin coating (for bismuth vanadate - BiVO4 thin film fabrication and PCBM deposition), and Successive Ionic Layer Absorption and Reaction -SILAR (for lead sulphide - PbS deposition) method and characterized using UV-visible Spectroscopy, time-resolved photoluminescence spectroscopy (TRPL), field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), and photoelectrochemistry (PEC) analysis (PEC). The key benefit of incorporation of PCBM nanoparticles in BiVO4/PCBM/PbS was realized through 1) ∼ 70% improvement in the photocurrent density during electrochemistry analysis, 2) ∼ 2.3 times enhancement in ABPE, and 3) ∼ 43% enhancements in ‘rate constant’ towards photocatalytic (methylene blue) degradation compared to BiVO4/PbS. The work shows the benefits of the PCBM-conductive carbon-based electron transport layer as a bridge between two inorganic semiconductors (BiVO4 and PbS) towards enhancing fast electron separation and transport at the interface during visible light irradiation.

Customized flexible iontronic pressure sensors: Multilevel microstructures by 3D-Printing for enhanced sensitivity and broad pressure range

Flexible capacitive pressure sensors stand out for their energy efficiency, rapid responsiveness, and exceptional durability, with their performance hinging on the intricate design of microstructures and the strategic selection of dielectric materials. However, creating cost-effective and practical fabrication methods for these components continues to pose a significant challenge. This study unveils an innovative iontronic flexible pressure sensor that integrates an ionic layer with sophisticated multilayer microstructures, setting new benchmarks in pressure sensing technology. The sensor operates within an expansive pressure range, achieving sensitivities as high as 92.14 kPa−1 at pressures from 0 to 50 kPa, and 22.96 kPa−1 at pressures ranging from 50 to 800 kPa, demonstrating extraordinary sensitivity. It also achieves an exceptionally low detection limit of 6.67 Pa and features swift response times of 56 ms to activate and 18 ms to deactivate. Enhanced by the addition of CuSO4, the sensor not only withstands freezing conditions but also significantly boosts sensitivity. Moreover, this sensor is capable of detecting human joint movements and subtle pressure fluctuations under high-pressure conditions, suggesting a breakthrough in the field. This research presents a simple, reliable, and cost-efficient method for developing flexible iontronic pressure sensors, poised to revolutionize applications in wide-ranging pressures and adverse temperature environments.

A Wearable Iontronic Sensor for Nasal Cannula-Facial Interface Pressure Distribution Evaluation

Enhancing the comfort of high-flow nasal cannulas holds practical significance in clinical settings, as it can alleviate pain during treatment, improve patient compliance, and reduce the occurrence of facial pressure sores during extended wear. The pressure distribution at the nasal cannula-facial interface is a key factor affecting comfort. In this paper, we present a flexible iontronic sensor with ultra-high sensitivity (up to 0.6 nF/mmHg), low activation pressure (as low as 1mmHg), and a fast response time (up to 30 ms) for measuring pressure at the nasal cannula-facial interface. The introduction of a poly (methyl methacrylate) (PMMA) bonding layer enables the ionic layer to form a robust sensing interface with the electrode. A unified pressure distribution measurement scheme was established, and 10 subjects were recruited to wear four brands of commercially available nasal cannulas to evaluate the dynamic pressure distribution in different states. The proposed device provides a feasible solution for assessing nasal cannula comfort and provides a quantitative evaluation framework for optimizing nasal cannula designs, with direct implications for patient care.

Analyzing antimicrobial activity of ZnO/FTO, Sn-Cu-doped ZnO/FTO thin films: Production and characterizations.

In the developing field of nanotechnology, ZnO (zinc oxide) based semiconductor samples have emerged as the foremost choice due to their immense potential for advancing the development of cutting-edge nanodevices. Due to its excellent chemical stability, low cost, and non-toxicity to biological systems, it is also utilized in various investigations. In this study, the successive ionic layer adsorption and reaction (SILAR) method was used to generate FTO (fluorine-doped tin oxide)/ZnO, and tin (Sn)-copper (Cu)-doped ZnO thin films at varying concentrations on FTO substrates. After being stacked 40 times in varying concentrations on the FTO substrate, FTO/ZnO thin films and Sn-Cu-doped thin films were annealed at 300°C. Using Scanning Electron Microscopy (SEM) Energy Dispersive Spectroscopy-(EDS), the agar diffusion test, and the viability cell counting method, the minimum inhibitory concentration, structural properties, surface morphology, antibacterial properties, bacterial adhesion, and survival organism count of FTO/ZnO thin films and Sn-Cu-doped thin films were investigated. Both doped and FTO/ZnO films with varying Sn-Cu concentrations expanded harmonically on the FTO substrate, according to the SEM-EDS investigation. The doping concentration affected their morphological properties, causing changes depending on the doping level. Antibacterial activity was observed in the powder metals, but no antibacterial activity was found in the thin film form. The highest adhesion rate of bacterial organisms on the produced samples was observed when the FTO/ZnO/Sn-Cu doping rate was 1%. In addition, the lowest adhesion rate was observed when the FTO/ZnO/Sn-Cu additive ratio was 3%. RESEARCH HIGHLIGHTS: ZnO based semiconductors highlight significant potential in advancing nanodevice technology due to their chemical stability, cost-effectiveness, and biocompatibility. Employing the SILAR method, the study innovatively fabricates FTO/ZnO and Sn-Cu-doped ZnO thin films on FTO substrates, exploring a novel approach in semiconductor manufacturing. Post annealing at 300°C, the research examines the structural and surface morphological changes in the films, contributing to the understanding of semiconductor behavior under varying conditions. The study delves into the antibacterial properties of ZnO thin films, offering insights into the potential biomedical applications of these materials. SEM-EDS analysis reveals that doping concentrations crucially influence the morphological properties of ZnO thin films, shedding light on the optimization of semiconductor performance. Findings indicate a specific doping rate (1% Sn-Cu) enhances bacterial adhesion, while a 3% additive ratio minimizes it, suggesting implications for biomedical device engineering and antibacterial surface design.

Optimizing Na2EDTA Concentration for Enhanced Properties of SILAR - Deposited CTS Thin Films

Abstract This study investigates the impact of varying Na2EDTA concentrations on the properties of copper tin sulfide (CTS) thin films deposited on soda lime glass substrates using the successive ionic layer adsorption and reaction (SILAR) method. The aim is to optimize CTS thin film growth for photovoltaic technology applications. CTS thin films were prepared using SILAR with Na2EDTA concentrations of 0.01M, 0.04M, and 0.07M, resulting in samples CTS01, CTS04, and CTS07. Characterization techniques included XRD, SEM, EDAX, FTIR, I-V curves, transmittance spectra, and Tauc plots. The results reveal significant variations in film properties with changing Na2EDTA concentration. XRD patterns indicate polycrystalline films with an orthorhombic CTS phase. SEM images show smooth, dense films with localized clusters. FTIR spectra detect hydrocarbon chains, aromatic rings, and hydroxyl or ether groups. The I-V curves of three samples (CTS01, CTS04, and CTS07) show a voltage-dependent transition from semiconducting to ohmic behavior. The CTS01 exhibits superior conductivity (3.13x10-5/Ωm), while the samples' resistance and conductivity values show an inverse relationship. Transmittance curves display low UV transmittance and high visible transmittance,suggests that the samples are highly absorptive in the UV range and become more transparent in the visible range, indicating potential applications in optical filtering and photovoltaic devices. Tauc plots estimate band gap energies of 3.66, 3.89, and 3.23 eV, indicating high band gap energies suitable for buffer layers in solar cells. The correlation between band gap energy and crystallite size as a function of Na2EDTA concentration is also observed. The study demonstrates the importance of optimizing Na2EDTA concentration for achieving high-quality CTS thin films with desirable properties for photovoltaic applications. The findings highlight the potential of CTS thin films for solar cells, optical filtering, and photonic devices.

Mechanics of electroadhesion of polyelectrolyte hydrogel heterojunctions enabled by ionic double layers

Mechanics of electroadhesion of polyelectrolyte hydrogel heterojunctions enabled by ionic double layers

Record high photocurrent density of In:Ag2S/ZnO heterojunction enabled by controllable doping for efficient solar hydrogen production

The high mobility of silver ions (Ag+) in silver sulfide (Ag2S) promotes vacancy formation, which serves as the recombination center of the photoexcited charge carriers to severely limit the photoelectrochemical activity of Ag2S. To address this issue, trivalent indium (In3+) is particularly introduced into Ag2S via low–temperature successive ionic layer adsorption and reaction (SILAR) technique, by which are the migration and the side reactions of Ag+ to form the phase impurities largely suppressed. Herein, In3+ is preferentially chosen due to its two more valence electrons with respect to that of Ag+, effectively increasing the carrier concentration of In:Ag2S to not only improve its electrical conductivity but also uplift its Fermi level. The photoexcited electron transport is thereby accelerated to more efficiently separate from the geminate holes, which is further reinforced by depositing In:Ag2S on the zinc oxide nanorods (ZnO NRs) with a relatively low–lying Fermi level. The photogenerated holes are rectified by the built–in electric field at the In:Ag2S/ZnO heterojunction to flow in an opposite direction to that of the electrons, between which the recombination is thereby suppressed. Meanwhile, the light harvesting ability of In:Ag2S/ZnO NRs is also enhanced due to its reduced band gap by In3+. Their synergistic effect renders In:Ag2S/ZnO NRs developed in the present contribution to deliver a record–high photocurrent density of 7.7 mA cm−2 under one–sun illumination, which far exceeds those of not only the undoped counterpart but also additional Ag2S–based photoelectrodes reported in the literature.

Enhancing energy storage with binder-free nickel oxide cathodes in flexible hybrid asymmetric solid-state supercapacitors

The need for flexible electrode materials for the development of flexible supercapacitors has drawn scientific interest recently. We present the successful synthesis of nickel oxide thin films using the successive ionic layer adsorption and reaction (SILAR) method, with the use of three different cationic precursors. This paper provides comprehensive details on the synthesized nickel oxide structure, morphology, and elemental analysis in addition to its electrochemical characteristics, which include specific capacitance (SCs), charge transfer resistance, etc. The produced nickel oxide electrodes achieved specific capacity as 120 C g−1, 517 C g−1, and 1147 C g−1 with different nickel precursors such as nickel chloride, nickel nitrate, and nickel sulfate respectively, at a 1 mA cm−2 current density. A flexible hybrid asymmetric solid-state supercapacitor (FHASS) (S:NiO//PVA-KOH//CuS) device delivered SCs of 165 Fg−1 at a 0.5 mA cm−2 current density, with a maximum SE of 58.87 Wh kg−1 at SP 347 W kg−1. FHASS device exhibits capacitive retention and coulombic efficiency of between 79 % and 96 % after 5000 successful GCD cycles. Also, the device retained an outstanding 97 % of its capacitance at a 175º bending angle. Furthermore, to illustrate its real-world applicability, the constructed device underwent 30 s of charging to a lightning LED table lamp for 90 s. The fabricated device is bringing a new era of broad integration of device-grade applications.

On the Role of Anions in Solid Catalysts with Ionic Liquid Layer (SCILL) for the Selective Hydrogenation of Highly Concentrated Acetylene Streams.

Electric plasma assisted pyrolysis of methane represents a highly promising greener alternative to produce ethylene from biogas and renewable energies compared to conventional steam cracking of naphtha. The mediocre performance of typical Pd-Ag catalysts for the downstream purification of the substantially higher concentrated acetylene impurities (≥15 vol.-%) in those ethylene streams via selective hydrogenation is yet limiting economic interest. Following the concept of solid catalysts with ionic liquid layer (SCILL), we have modified an intrinsically non-selective palladium catalyst with imidazolium based ionic liquids varying among 10 different anions and investigated them in this reaction. The best performing [C4C1IM][MeSO4]-SCILL reaches an outstanding average ethylene selectivity over 20 h on-stream of 82 % at full acetylene conversion without any sign of deactivation, clearly outperforming conventional Pd-Ag catalysts. By varying parameters like ionic liquid (IL) loading, temperature, feed gas composition, cations, and by using XPS for surface analysis we could gain a very comprehensive understanding of the underlying mechanisms that reduce the competing over-hydrogenation and oligomerisation side-reactions.

Preparation of PbS/TiO2 nanotube films for enhanced photoelectrochemical response and cathodic protection performance

Anodic oxidation method and sonication-assisted successive ionic layer adsorption and reaction (S-SILAR) process were used to prepare TiO2 nanotube films and PbS/TiO2 nanotube films. The effects of impregnation times on photoelectrochemical (PEC) performance of PbS/TiO2 nanotube films were systematically studied. The PEC properties were evaluated by UV–vis DRS, I-t, EIS and coupling potential. When PbS nanoparticles were impregnated for 15 times, the bandgap of PbS/TiO2 was narrowed to 1.4 eV, and the photocurrent density could reach 4.14 mA﹒cm−2, which increased by 12.8 times compared with TiO2. PbS nanoparticles loading onto TiO2 nanotube films is a simple and effective way to enhanced PEC response and cathodic protection performance.

Rational design of ZnO-SnO2 Janus nanofibers for highly sensitive triethylamine detection

Herein, ZnO-SnO2 Janus nanofibers (NFs) were synthesized by a parallel electrospinning method and its sensing performances were tested. Considering the compositions of the two metal oxide semiconductors in Janus structure, different ratios of ZnO and SnO2 were designed and controlled. The optimum ratios of ZnO and SnO2 was 1:2 by analyzing their sensing performances to triethylamine (TEA) gas. Gas sensors based on ZS-12 Janus NFs exhibited a high response to TEA (45.2) and an excellent sensing response/recovery reproducibility. In order to investigate the sensing mechanism of Janus structure, ZnO NFs and SnO2 NFs were synthesized and used as controlled experiment. The results indicated that the heterostructures in Janus NFs is the key factor for the enhanced TEA sensing performances. The electrons flowed in the ZnO-SnO2 Janus structure leading to the variation of ionic oxygen species and electron depletion layer. These phenomena improved the reaction of TEA gas molecules with ionic oxygen species so that the TEA sensing performances were enhanced. Based on the Janus structures, a satisfactory gas sensor for detecting TEA gas were developed. Significantly, this work investigated the sensing mechanism of Janus structures and provided an efficient strategy for the gas sensing materials.

SILAR-assisted synthesis of Cu2O modified TiO2 nanotube arrays: Study on efficient photocatalytic dye degradation and hydrogen evolution

Dye wastewater and energy shortage are two large inhibition factors, and photocatalytic applications have proven to be an effective strategy to overcome the above crises in various areas such as wastewater remediation and H2 production. Herein, the TiO2 NTs/Cu2O photocatalyst was created by depositing Cu2O onto TiO2 nanotube arrays (TiO2 NTs), with the number of successive ionic layer adsorption and reaction (SILAR) deposition cycles playing a significant role in determining the photoelectrochemical performance. The TiO2 NTs/Cu2O (9) showed the outstanding visible light photocurrent, pollutant removal and H2 evolution. TiO2 NTs/Cu2O (9) successfully removed MO, RhB, MB and Cr(VI) with the degradation efficiencies of 99.32 %, 69.63 %, 99.27 % and 72.55 %, and it also showed the optimal H2 evolution rate (49.67 μmol·cm−2·h−1). Furthermore, the Z-scheme photocatalytic mechanism was proposed, and the dye decomposition was primarily caused by the presence of O2 radicals.

Fabrication and Characterization of Aluminum-Doped Nickel Oxide Thin Films for Optoelectronic Applications using the SILAR Method

Study’s Excerpt The effect of varying annealing times on 10% Aluminum-doped Nickel Oxide (ANO) thin films, deposited via the SILAR technique is presented. SEM and RBS analyses were used for detailed correlation between annealing time and the film's microstructural improvements. ANO thin films could be used for advanced technological applications. Full Abstract The effect of varying the annealing time of %10 aluminium-doped Nickel Oxide thin film was studied to understand the possible effect on the optical, structural, and electrical properties of %10 aluminium-doped Nickel Oxide (ANO) for possible application. The thin films were deposited on glass substrates using the successive ionic layer adsorption reaction (SILAR) deposition technique. The samples formed were annealed at 3000C, and the annealing time varied at 1.35 hrs., 1.45 hrs., 1.55 hrs., and 2 hrs, respectively. The deposited films were characterized to obtain the optical, electrical, and structural characteristics and the compositional constituent of the film using the double beam photo spectrometer, Four-Point Probe, Scanned electron Microscope, Energy Dispersion Spectroscopy, and X-ray Diffractometer. The films were observed to have low absorbance in the range of 0.1 to 0.01 and high % transmittance within the range of 80% - 98% in the visible region of the spectrum. The reflectance of the film was observed to decrease with an increase in annealing time in the range of 10% - 2.5%, all in the visible region of the spectrum. The crystallite size of the deposited films decreased with increased annealing time with the structural formation of simple cubic phase NiO thin film. SEM micrograph of the thin films reveals that an increase in annealing time improved the crystallinity of the films with the grain size evenly distributed. The EDS result of the deposited films revealed the presence of nickel, aluminum and Oxygen as the major constituent of the deposited films. The Ruther Ford Backscattering (RBS) analysis of the thickness of the films shows an increase in the thickness with an increase in annealing time. Clearer compositions of the films were also seen from the RBS analysis. Their electrical properties revealed that the films formed had low electrical resistivity and high conductivity, so they could be useful in making optoelectronics devices and corrosion resistance.

Cover Feature: Assessing Solid Catalysts with Ionic Liquid Layers (SCILL) from Molecular Dynamics Simulations: On the Role of Local Charge Polarization (Chem. Eur. J. 57/2024)

Cover Feature: Assessing Solid Catalysts with Ionic Liquid Layers (SCILL) from Molecular Dynamics Simulations: On the Role of Local Charge Polarization (Chem. Eur. J. 57/2024)

The Impact of Thermal Treatment on the Structural, Optical and Electrochemical Characteristics of Tin Sulfide Films

The development of eco-friendly, cost-effective, and naturally abundant electrode materials for supercapacitors is gaining critical importance in current energy storage research. This study focuses on the synthesis of tin sulfide (SnSx) films via the eco-friendly successive ionic layer adsorption and reaction (SILAR) method, employing varying quantities of L-ascorbic acid (0.8 and 1.0 g) as a reducing agent. Tin sulfide films were deposited on fluorine-doped tin oxide (FTO) glass substrates and subsequently annealed in an inert atmosphere at temperatures ranging from 200 to 400 °C, resulting in thin films of varying thicknesses (100–420 nm). The structural and compositional characteristics of the films were thoroughly analyzed using Raman spectroscopy to confirm the purity and spectroscopic signatures of the sulfides. Further characterization was performed to assess the films’ morphology (scanning electron microscopy, SEM), phase composition (X-ray diffraction, XRD), surface chemical states (X-ray photoelectron spectroscopy, XPS), optical properties (UV–Vis spectroscopy), and electrical properties (Hall measurements). The gathered data were then used to evaluate the potential of tin sulfide films as electrode materials in supercapacitors, highlighting their suitability for sustainable energy storage applications.

Quantum Effects at a Spin-Flop Transition in the Antiferromagnetic Topological Insulator MnBi2Te4

It is shown that the experimentally detected features in the low-temperature behavior of the magnetization in an external magnetic field perpendicular to the layers of manganese ions of the topological antiferromagnet MnBi2Te4 are due to quantum effects induced by the off-diagonal nature of the trigonal component of the crystal field. In this case, the anomalous increase in the magnetization of the material before the spin-flop transition, as well as after it in the phase of “collapsed” sublattices, is explained by the suppression of contributions from quantum effects. The comparison of the results of the theoretical analysis with experimental data has made it possible to refine the parameters of the effective spin model of MnBi2Te4 and to establish the important role of the noted trigonal component.

Ionic buffer layer design for stabilizing Zn electrodes in aqueous Zn-based batteries

Aqueous Zn-based batteries (AZBs) are hindered by issues associated with the Zn electrodeposition process (ZEDP) on electrode surfaces, including passivation, dendrite formation, and hydrogen evolution. One of the important reasons is the drastic fluctuation in the concentration of Zn2+ ions on the electrode surface during the charging and discharging process. In this work, an electrolyte with Zn2+ ion buffer layer (EZIBL) is proposed to regulate the ZEDP. First, numerical simulations and corresponding experiments are conducted to assess the impact of different thicknesses of the Zn2+ ion buffer layer (ZIBL) on the variation in Zn2+ ion concentration, from which the optimal thickness of the ZIBL is determined. Then, the regulation role of EZIBL in the cycling process is demonstrated by a Zn-Cu half cell. Further, combined with the potential profile of the symmetric cell and the experimental phenomena, the regulation role of EZIBL in ZEDP is systematically explained at the mechanistic level through the analysis of key parameters. Finally, a full battery composed of Zn-LiMn2O4 is assembled to evaluate the practical applicability of the EZIBL in real battery cycles, which shows great enhancement in capacity retention and coulombic efficiency. This work proposes the design of the EZIBL used to regulate the ZEDP and provides a simple, low-cost regulation method for the development of high-performance AZBs.

Structural, Morphological, and Optical Properties of TiO2/CdS Core-Shell System Prepared by Two Method for Photoelectrocatalytic Application

Abstract The present study utilized the hydrothermal technique to carry out the deposition of films of TiO2. The deposition of CdS on the TiO2 films was accomplished using the chemical bath deposition (CBD) and successive ionic layer adsorption and reaction (SILAR) methods. The morphological and structural characteristics of the TiO2/CdS thin films were investigated using a combination of XRD, SEM, EDX, and AFM techniques. Additionally, the optical properties of the nanostructures were examined using UV-Visible and PL spectroscopic techniques. The X-Ray Diffraction pattern of all TiO2 films revealed the formation of the anatase phase. The CdS present in the Ti/TiO2/CdS samples exhibited a hexagonal structure. The hydrothermal technique employed in the preparation of the TiO2 thin films resulted in the formation of nanofiber morphology, which was evident from the SEM images. The absorption edge data for the TiO2/CdS films demonstrated a shift towards the visible region, indicating a decrease in the bandgap as compared to the TiO2 nanostructure. Significantly improved photoelectrocatalytic performance was observed in the Ti/TiO2/CdS samples prepared using the CBD method, surpassing that of the Ti/TiO2/CdS samples prepared using the SILAR method.

Improving photoelectrochemical performance of transferred TiO2 nanotubes onto FTO substrate with Mo2C and NiS as Co-catalyst

The photoelectrochemical (PEC) performance of titanium dioxide nanotube (TiO2 NT) photoelectrodes for sustainable hydrogen production has garnered significant research interest. Despite the advantages of TiO2 NT fabricated via anodization of titanium metal, such as their well-ordered vertical structure, challenges persist including the thick oxide barrier layer, limited optical transparancy, and the wide energy band gap (∼3.0 eV), which constrain their practical efficiency in PEC applications. This study addresses these limitations by introducing a novel approch to transfer TiO2 NT onto a fluorine-doped tin oxide (FTO) substrate. TiO2 NTs were synthesized with varying anodization times and steps to achieve optimal free-standing structures. To further enhance PEC performance, co-catalyst including molybdenum carbide (Mo2C) and nickel sulfide (NiS) were incorporated using immersion and successive ionic layer adsorption reaction (SILAR) methods, respectively. Comprehensive characterization using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), ultraviolet–visible–near infrared (UV–Vis–NIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) provided insights into the crystal phase, morphological structure, band gap, and elemental composition of the photoelectrodes. Photoelectrochemical and photostability evaluations were conducted through linear scan voltammetry (LSV) and chronoamperometry under dark and light conditions. Results indicate that transferring TiO2 NTs onto FTO significantly enhanced photocurrent density, achieving a 2.5-fold increase at 0.7 V versus a TiO2 NT/Ti substrate. The incorporating of co-catalysts Mo2C, NiS and the combined NiS/Mo2C further enhanced the photocurrent density to 2.20, 3.00 and 8.00 mA cm−2 respectively, with a remarkable 31-fold enhancement compared to the TiO2 NT/Ti substrate. This findings underscore the potential of the TiO₂ NT/FTO photoelectrode with optimized co-catalyst integration for advanced photoelectrochemical applications.

Micron silicon-oxide-carbon coated with TiOx(OH)y layer as better performance anode for lithium-ion batteries

Micron-silicon based material is a promising anode material for high performance lithium batteries due to its ultra-high specific capacity. However, the volume expansion exceeds 300 % during charging and discharging, resulting in the collapse of the electrode structure and a rapid decline in electrochemical performance. Coating the surface of silicon-based materials with flexible ionic conductors is an effective method to maintain their high capacity and suppress swelling. Here, to further improve the electrochemical performance of silicon-based materials, we have deposited a titanate-type ionic conductor layer on a micron-sized silicon-carbon oxide (SiOX-C) material to synthesize the SiOX-C@TiOx(OH)y material. The TiOx(OH)y layer not only exhibits the elastic properties of a superpolymer to mitigate swelling strain, but also has a fast capacitance effect to improve its rate performance. In addition, the interfacial charge transport of SiOX-C@TiOx(OH)y is enhanced due to the structural diversity of the TiOx(OH)y layer. For the above mechanisms, the SiOX-C@TiOx(OH)y has a specific capacity of 278.3 mAh g−1 under high current of 3500 mA g−1. Meanwhile, the SiOX-C@TiOx(OH)y with the capacity retention of 67 % is achieved at 2000 mA g−1 after 100 cycles.