Abstract Amorphous silicon oxycarbide (SiOC) demonstrates high capacity for anode material of lithium‐ion batteries (LIBs). However, its low initial coulombic efficiency (ICE), poor electrical conductivity, and unstable solid electrolyte interphase (SEI) present significant challenges for practical application. Here, porous SiOC hierarchical spheres are elaborated by pyrolysis of cooperatively self‐assembled mesostructure, followed by an alkaline chemical etching process. Moreover, their electronic conductivity and mechanical strength are enhanced by decorating with well‐dispersed Fe/FeO nanoparticles (NPs). The cooperative interaction between the 3D nanoporous SiOC framework and its interconnected hierarchical structure provides rapid diffusion pathways and facilely accessible active sites for Li + ion insertion. The enhanced electronic and ionic conductivity of SiOC‐Fe anode facilitates the formation of a robust LiF‐rich SEI layer, which is found to be ionically more conductive and enables effective passivation of the anode/electrolyte interface, thereby ensuring long‐term cycling stability. Owing to the special nanostructure engineering and SEI, our prepared SiOC‐Fe anode exhibits an excellent cycling stability (635.3 mAh g −1 after 1200 cycles at 1.0 A g −1 ) as well as outstanding rate performance (277.3 mAh g −1 at 2.0 A g −1 ). Furthermore, the full cells assembled with an LiFePO 4 cathode demonstrate a high specific capacity of 140.0 mAh g −1 after 100 cycles. The work provides valuable insights into designing SiOC‐based anodes through metal NPs modification and nano‐morphologies construction for advanced LIBs.

The increasing demand for carbon neutrality has accelerated the adoption of electric vehicles and large-scale energy storage systems, traditionally powered by lithium-ion batteries. However, concerns about the limited availability and rising cost of lithium resources have prompted growing interest in sodium-ion batteries, which offer advantages in abundance and cost-effectiveness.While hard carbon has been widely used as a commercial anode material for sodium-ion batteries, its limited capacity has driven the search for alternative high-capacity materials. Alloy-type materials, such as Sn and SnSb, are promising candidates due to their high theoretical capacities. Nonetheless, their practical application is hindered by challenges including severe volume changes, sluggish reaction kinetics, and interfacial instability during cycling.To overcome these issues, we developed heterostructured composite anodes by integrating active materials with a porous silicon oxycarbide (SiOC) matrix, which offers excellent mechanical robustness and surface capacitive properties. Through controlled dispersion of precursors in silicon oil followed by heat treatment, alloy-based high-capacity composites (Sn@SiOC and SnSb@SiOC) were successfully synthesized. Comprehensive structural, physicochemical, and electrochemical characterizations—including post-mortem analyses—revealed that the heterostructure effectively mitigates degradation and enhances sodium storage performance.Our findings demonstrate the potential of heterostructured anodes to significantly improve the energy density and cycling stability of sodium-ion batteries, contributing to the development of next-generation energy storage technologies.

Hydrogen peroxide is a little explored oxidant for the deposition of silicon dioxide or silicon oxycarbide films. In this work, we discuss the atomic layer deposition of SiO2 and SiOC films using a variety of hydrogen peroxide sources, demonstrating the critical impact of water on the growth rate and properties of the resulting silicon-containing films. It will be shown that with the correct choice of hydrogen peroxide source and silicon precursor, SiO2 and SiOC films can be grown at ambient temperatures in a thermal ALD process . Furthermore, the low temperatures and specific oxidation conditions of these processes afford ample opportunity for selective growth on a variety of substrate combinations, such as dielectric-on-dielectric, dielectric-on-metal, and dielectric-on-semiconductor. Plasma-based and thermal densification of the resulting films will also be discussed, as will deposition of SiO2 on oxidatively or temperature sensitive substrates such as polymer films and pharmaceutical compounds.

The development of high-speed computers and electronic memories, high-frequency communication networks, electroluminescent and photovoltaic devices, flexible displays, and more requires new materials with unique properties, such as a low dielectric constant, an adjustable refractive index, high hardness, thermal resistance, and processability. SiOC coatings possess a number of desirable properties required by modern technologies, including good heat and UV resistance, transparency, high electrical insulation, flexibility, and solubility in commonly used organic solvents. Chemical vapor deposition (CVD) is a very useful and convenient method to produce this type of layer. In this article we present the results of studies on SiOC coatings obtained from tetramethylcyclotetrasiloxane in a remote hydrogen plasma CVD process. The elemental composition (XPS, EDS) and chemical structure (FTIR and NMR spectroscopy-13C, 29Si) of the obtained coatings were investigated. Photoluminescence analyses and ellipsometric and thermogravimetric measurements were also performed. The surface morphology was characterized using AFM and SEM. The obtained results allowed us to propose a mechanism for the initiation and growth of the SiOC layer.

In this work, various aromatic monocarboxylic and dicarboxylic acids were subjected for the first time to a vinylation reaction with acetylene under heterogeneous catalytic conditions using catalytic systems based on silicon oxycarbide supported on silicon carbide (SiC): zinc silicon oxycarbide (Zn/SiOC), zinc oxide silicon oxycarbide (ZnO/SiOC), and nickel silicon oxycarbide (Ni/SiOC). The influence of the nature of the starting materials, temperature, reaction duration, solvent, and catalyst type on the yield of vinyl esters was investigated. The vinylation reaction of aromatic carboxylic acids with acetylene was carried out at 1:2 molar ratio, using a Zn/SiOC-50 catalytic system at a loading of 10 mol% relative to the initial aromatic carboxylic acid, in a N,N-dimethylformamide (DMF) solution at 150 C for 12 h, resulting in high yields of vinyl esters. Under these heterogeneous catalytic conditions, the vinylation reaction afforded the following vinyl esters: benzoic acid (80%), 4-methylbenzoic acid (77%), 4-methoxybenzoic acid (70%), 4-fluorobenzoic acid (83%), 4-tert-butylbenzoic acid (65%), 4-chlorobenzoic acid (85%), divinyl esters of ortho-phthalic acid (88%), and terephthalic acid (91%). The structures of the synthesized vinyl esters were confirmed by Fourier-transform infrared (FTIR), proton nuclear magnetic resonance (1H NMR), carbon-13 nuclear magnetic resonance (13C NMR), and chromatographic-mass spectral (MS) analyses.

The precursor-derived ceramic route is recognized as an advanced and efficient technique for fabricating ceramic matrix composites, particularly suitable for the development and microstructural tailoring of continuous fiber-reinforced ceramic matrix composites. In this work, octamethylcyclotetrasiloxane and tetravinylcyclotetrasiloxane were employed as monomers to synthesize a branched siloxane via ring-opening polymerization. A subsequent hydrosilylation reaction led to the formation of polyvinylsiloxane with a three-dimensional crosslinked structure. The precursor exhibited excellent fluidity, adjustable viscosity, and superior thermosetting characteristics, enabling efficient impregnation and densification of reinforcements through the polymer infiltration and pyrolysis process. Upon pyrolysis, the polyvinylsiloxane gradually converted from an organic polymer to an amorphous inorganic ceramic phase, yielding silicon oxycarbide ceramics with a high ceramic yield of 81.3%. Elemental analysis indicated that the resulting ceramic mainly comprised silicon and oxygen, with a low carbon content. Furthermore, the material demonstrated a stable dielectric constant (~2.5) and low dielectric loss (<0.01), which are beneficial for enhanced thermal stability and dielectric performance. These findings offer a promising precursor system and process reference for the low-cost production of high-performance, multifunctional ceramic matrix composites with strong potential for engineering applications.

In most commercial lithium-ion batteries, graphite remains the primary anode material. However, its theoretical specific capacity is only 372 mAh∙g-1, which falls short of meeting the demands of high-performance electronic devices. Silicon anodes, despite boasting an ultra-high theoretical specific capacity of 4200 mAh∙g-1, suffer from significant volume expansion (>300%) during cycling, leading to severe capacity fade and limiting their commercial viability. Currently, silicon-based polymer-derived ceramics have emerged as a highly promising next-generation anode material for lithium-ion batteries, thanks to their unique nano-cluster structure, tunable composition, and low volume expansion characteristics. The maximum capacity of the ceramics can exceed 1000 mAh∙g-1, and their unique synthesis routes enable customization to align with diverse electrochemical application requirements. In this paper, we present the progress of silicon oxycarbide (SiOC), silicon carbonitride (SiCN), silicon boron carbonitride (SiBCN) and silicon oxycarbonitride (SiOCN) in the field of LIBs, including their synthesis, structural characteristics and electrochemical properties, etc. The mechanisms of lithium-ion storage in the Si-based anode materials are summarized as well, including the key role of free carbon in these materials.

Silicon oxycarbide coatings are the subject of research due to their exceptional optical, electronic, anti-corrosion, etc., properties, which make them attractive for a number of applications. In this article, we present a study on the synthesis and characterization of thin SiOC:H silicon oxycarbide films with the given composition and properties from a new organosilicon precursor octamethyl-1,4-dioxatetrasilacyclohexane (2D2) and its macromolecular equivalent—poly(oxybisdimethylsily1ene) (POBDMS). Layers from 2D2 precursor with different SiOC:H structure, from polymeric to ceramic-like, were produced in the remote microwave hydrogen plasma by CVD method (RHP-CVD) on a heated substrate in the temperature range of 30–400 °C. SiOC:H polymer layers from POEDMS were deposited from solution by spin coating and then crosslinked in RHP via the breaking of the Si-Si silyl bonds initiated by hydrogen radicals. The properties of SiOC:H layers obtained by both methods were compared. The density of the cross-linked materials was determined by the gravimetric method, elemental composition by means of XPS, chemical structure by FTIR spectroscopy, and NMR spectroscopy (13C, 29Si). Photoluminescence analyses and ellipsometric measurements were also performed. Surface morphology was characterized by AFM. Based on the obtained results, a mechanism of initiation, growth, and cross-linking of the CVD layers under the influence of hydrogen radicals was proposed.

Abstract Ceramic materials are valued for their exceptional heat and corrosion resistance, yet their inherent brittleness limits their use in applications requiring high strength‐to‐weight ratios, fatigue resistance, and durability under harsh conditions, such as those in the aerospace and automotive industries. The development of ceramic matrix composites (CMCs), incorporating continuous reinforcements, has enhanced the mechanical performance of ceramics, offering superior toughness compared to randomly oriented composites. Traditional fabrication methods for composites, such as polymer infiltration and pyrolysis (PIP) and chemical vapor infiltration (CVI), are effective but constrained by shaping complexities. Direct ink writing (DIW) has emerged as a fabrication approach for CMCs fabrication, enabling custom geometries and tailored reinforcement architectures. Extrusion‐based processes naturally align fibers, optimizing their orientation and enhancing composite properties. This study focuses on the fabrication of silicon oxycarbide matrix reinforced with continuous carbon fibers using two DIW approaches. Comparative analysis highlighted the benefits and limitations of each method, with post‐processing via PIP addressing crack formation and improving densification. Mechanical properties were evaluated at different fabrication stages, revealing key relationships between processing techniques and final composite performance.

ABSTRACT Polymer-derived silicon oxycarbide (SiOC), known for their exceptional thermal stability, corrosion resistance, and adaptability to additive manufacturing, are highly promising for thermal protection applications. The thermal properties of SiOC materials are significantly influenced by their microstructures, which can be manipulated through controlled pyrolysis conditions. To explore this relationship, understanding the thermal conductivity of pure SiOC glass is crucial. In this work, we employ a recently developed machine-learning interatomic potential coupled with Wigner transport theory to investigate the thermal properties of fused silica and SiOC glass. We discover that SiOC glass exhibits lower thermal conductivity than fused silica, with a weak temperature dependence above 600 K. Detailed analyses of the spectral distribution function and participation ratio reveal that carbon atoms enhance the localisation of vibrational modes by altering the silicon–oxygen tetrahedron networks. Furthermore, the introduction of sub-nanometre pores substantially reduces thermal conductivity, primarily due to density changes that affect specific heat. This research offers valuable insights into the thermal transport properties of SiOC glass and lays the groundwork for developing analytical models to predict the thermal conductivity of SiOC glass ceramics with dispersed nanodomains.

The journal retracts the article titled “Physical and Thermal Studies of Carbon-Enriched Silicon Oxycarbide Synthesized from Floating Plants” [...]

Silicon oxycarbide (SiOC) is a versatile ceramic material with tunable microstructure and compositions that can be modulated through precursor chemistry and processing conditions. Though there are several noteworthy uses of SiOC across a range of application spaces, the difficulties in elucidating the short- to medium-range order within these materials have limited the maturation of strategies to precisely control SiC x O4-x compositions for user-tailored applications. In this contribution, we implement a range of synchrotron scattering and spectroscopy methods coupled with stochastic modeling techniques to elucidate changes in local chemistry and structure associated with the pyrolysis of a commercially available SiOC polymer precursor. Stochastic modeling approaches provide valuable insights into decoupling local Si-O and Si-C environments while confirming predominate heterogeneous phases in materials. Using pyrolysis temperatures between 250 to 800 °C results in a heterogeneous material predominately composed of SiOC and amorphous SiO2 domains. At 1100 °C, redistribution of Si-C pairs in the SiOC network and Si-O from the SiO2 domains create a more ordered SiOC phase with local cubic SiC-like ordering. In addition, residual carbon leads to a detectable carbon phases at 1100 °C that persist at higher temperatures. These efforts address the difficulties of obtaining atomic-scale insights into the local structure and nanoscale heterogeneities in SiOC, providing pathways toward establishing structure-property relationships for future materials development.

The implementation of stereolithography (SLA) for fabricating 3D-structured polymer-derived ceramics (PDCs) has greatly improved the resolution, manufacturing potential, and widespread capability to produce complicated component geometries in ceramic materials. However, different material systems impose challenges to the traditional UV SLA photo-cross-linking process due to a narrow window of material selection requirements-UV transparency, UV degradation resistance, the ability to support the photoinduced radical curing mechanism, and ambient shelf life stability. Herein, a near-infrared (NIR) thermal SLA printing technology is demonstrated on a composite thermally curable acrylate-based highly loaded resin to overcome current issues with UV light-driven SLA additive manufacturing of preceramic polymers (PCP). For this thermal SLA cross-linking method, a high-intensity NIR laser (λ = 808 nm) was used to generate localized thermal heating at the resin pool interface, which led to rapid, targeted thermal free-radical polymerization and solidification of the SiC particle-laden acrylate-based resin during laser scanning. Thermally cured printed parts were demonstrated using a gantry-based movement platform and a resin pool in a top-down laser scanning configuration. After printing, the green bodies were debinded, followed by polymer infiltration and pyrolysis (PIP) during postprocessing, which enhanced the mechanical strength of the pyrolyzed samples. This work demonstrated the fabrication of a reinforced PDC composite material with crystalline silicon carbide (SiC) fillers and an amorphous matrix made of silicon oxycarbide (SiOC) and silicon carbonitride (SiCN). The flexural strength of the NIR-printed samples reached 48 MPa with a fracture toughness of 4 MPa·m1/2.

Effect of substrate temperature on silicon Oxycarbide thin films prepared by catalytic chemical vapor deposition

Known for their strength and durability, ceramic materials are often limited by their brittleness. Polymer-derived ceramics (PDCs) offer a promising alternative, enabling the fabrication of complex shapes that traditional ceramics struggle to achieve. This study introduces a cost-effective method for producing robust PDCs using low-cost liquid crystal display (LCD) 3D printing combined with strategic nanofiller integration. By incorporating nanofillers such as silicon nitride and alumina into a silicon oxycarbide precursor (SPR-684) matrix, we significantly enhanced the mechanical properties of the resultant ceramics. Optimized formulations, including a photoinitiator for vat photopolymerization, were 3D printed into complex geometries, such as gyroids and lattices, and subsequently converted to ceramics through pyrolysis. We systematically investigated the effects of varying nanofiller concentrations (0.2 to 1 wt%) on the density, microstructure, and mechanical performance of the PDC lattices. The results showed remarkable improvements, with increases of up to 2060% in toughness, 20% in stiffness, and 900% in compressive strength attributed to nanofiller integration. In terms of biocompatibility, cytotoxicity assays revealed high cell viability and proliferation on the fabricated PDC scaffolds, indicating minimal cytotoxicity and supporting cell adhesion—key attributes for tissue integration in biomedical applications. Moreover, the compressive properties of the nanofiller-enhanced ceramics closely matched those of human trabecular bone, underscoring their suitability as load-bearing bio-implants. This LCD 3D printing method offers versatility, precision, and cost-effectiveness for bioceramic fabrication, positioning these materials as promising candidates for future biomedical devices where both mechanical performance and biocompatibility are critical.

A significant challenge during the polymer-to-ceramic pyrolysis conversion is to understand the polymer-to-ceramic atomic evolution and correlate the composition changes with the precursor molecular structures, pyrolysis conditions, and resulting ceramic characteristics. In this study, a Reactive Force Field (ReaxFF) simulation approach has been used to simulate silicon oxycarbide (SiOC) ceramic formation from four different polysiloxane precursors. For the first time, we show atomically that pyrolysis time and temperature proportionally impact the new Si-O rich and C rich cluster sizes as well as the composition separation of Si-O from C. Polymer side groups have a more complex effect on the Si-O and C cluster separation and growth, with ethyl group leading to the most Si-O cluster separation and phenyl group leading to the most C cluster separation. We also demonstrate never-before correlations of gas release with polymer molecular structures and functional groups. CH4, C2H6, C2H4, and H2 are preferentially released from the pyrolyzing systems. The sequence is determined by the polymer molecular structures. This work is the first to atomically illustrate the innate correlations between the polymer precursors and pyrolyzed ceramics.

This study demonstrates the fabrication of high‐strength, lightweight polymer‐derived ceramics (PDCs) using silicon oxycarbide (SiOC)‐precursor formulations with liquid crystal display (LCD) vat photopolymerization (VPP) technology. Complex geometries, such as gyroids and stochastic lattices, are successfully 3D‐printed and evaluated under varying feature thicknesses and pyrolysis temperatures (800 °C and 1200 °C). Photorheology and thermogravimetric analysis (TGA) validated the efficient curing and pyrolysis characteristics of a printable precursor formulation based on vinyl methoxysiloxane homopolymer (VMM‐010), which demonstrated rapid curing, low viscosity, and compatibility with LCD 3D printing, ensuring precise layering and efficient resin removal. Micro‐CT scans confirmed its structural integrity and absence of voids, even in relatively thick components (≈3 mm). The VMM‐based PDC lattices achieved specific compressive strengths up to 9.4 MPa g⁻¹ cm3, a 50‐fold improvement over comparable lattices produced with a high‐porosity SiOC PDC, and exceptional high‐temperature stability, maintaining structural integrity after 2 h at 1500 °C. Compositional analysis revealed lower free carbon content and improved ceramic phase formation, driving the enhanced mechanical and thermal performance of the VMM‐based ceramic. These findings underscore the scalability, reliability, and superior performance of VMM formulations for LCD 3D printing, offering new possibilities for high‐performance ceramic applications in aerospace, automotive, and biomedical industries.

Abstract Lightweight ablative thermal protection materials (TPMs) with excellent ablation, thermal insulation, and anti‐oxidation are urgently needed for aerospace vehicles. Herein, a distinct strategy was proposed that uses aerogel‐like polysiloxane (SiA) as a matrix, and carbon‐bonded carbon fiber (C/C) composite as reinforcement to construct a lightweight SiA impregnated C/C (C/C‐SiA) composite, through vacuum impregnation, sol–gel, and atmospheric pressure drying. The intriguing characteristics including high mechanical strength and stiffness, thermal stability and oxidation resistance, and a low thermal conductivity of 0.063 W/(mK) were integrated into the low‐density (0.238–0.306 g/cm 3 ) C/C‐SiA. The synergistic effect originated from pyrolysis products of SiA including silicon oxycarbide ceramic to inhibit oxygen diffusion and pyrolysis gas to retard convective heat transfer, the high emissivity surface re‐radiation to dissipate heat and transverse thermal conductivity to regulate heat transfer by C/C, enables C/C‐SiA to deliver remarkable thermal insulation performance (20 mm backside temperature below 40°C on a heating plate for 1800 sec) and ablation resistance (near‐zero surface recession of 0.18 μm/s exposed to 1300°C flame for 1200 sec). The ceramifiable strategy can be extended to other preceramic polymers, such as polycarbosilane, polysilazane, and ZrO 2 precursor, which may open a new avenue for improving lightweight ablative TPMs. Highlights Aerogel‐like polysiloxane lightweight ablative material was fabricated. The synergistic effect gives excellent mechanical and thermal properties. Surface re‐radiation and heat blockage dissipate the main heat continuously. In‐situ formed ceramic to inhibit diffusion enables long‐term anti‐oxidation.

A silicon oxycarbide (SiOC) ceramic composite produced via a high-temperature spark plasma sintering process exhibits excellent mechanical robustness, high electrical conductivity, and low thermal conductivity, useful for various applications.

We report on the synthesis and characterization of HfOC/SiOC ceramic composite powders and electrospun fibermats, which integrate the high-temperature resilience of HfOC with the oxidation resistance of silicon oxycarbide (SiOC). The composites were fabricated through a polymer-pyrolysis route by integrating 1,3,5,7-tetramethyl, 1,3,5,7-tetravinyl cyclotetrasiloxane (4-TTCS), a precursor source for SiOC, and a commercial HfC precursor in a 1 : 1 ratio by mass. First, the HfC precursor was heated to 70 °C to drive off water molecules, followed by its blending with the liquid phase 4-TTCS and cross-linking at a moderate temperature (160-400 °C). This was followed by pyrolysis at three different temperatures - 800, 1000, and 1200 °C in an inert argon atmosphere. The composite ceramic was comprehensively characterized by the use of electron microscopy for particle and fiber morphology, X-ray diffraction for the evolution of various ceramic phases, and a range of spectroscopies to document the change in molecular vibrations or the evolution of the functional groups and molecular bonding in preceramic polymer during cross-linking and ceramization. The crosslinked polymer-to-ceramic yield for powder samples was observed to be as high as approximately 78 wt% when pyrolyzed at 800 °C, and 74 wt% when pyrolyzed at 1200 °C. The oxidation test performed at 800 °C in stagnant air for the fibermat pyrolyzed at 1000 °C indicated a linear shrinkage of 6% for the HfOC/SiOC composite. This represents an improvement over the carbon rich-SiOC fibermat which exhibited a mass loss of 71 wt% and a linear shrinkage of nearly 19%, while the neat carbon fibermat was completely burned off under similar conditions.