Self-supporting Network Research Articles

Vanadium-Doped Ni3S2: Morphological Evolution for Enhanced Industrial-Scale Water and Urea Electrolysis.

We report the V-Ni3S2 self-supported catalytic network with optimized morphology grown directly on nickel foam (NF) by the one-step hydrothermal technique for water and urea electrolysis at industrial scale hydrogen generation. The morphology of Ni3S2 was modulated by doping of different concentrations of vanadium from granules to cross-linked wires to hierarchal nanosheets arrays, which is beneficial in electrochemical charge and mass transport, and generates more exposed active sites. The V-Ni3S2 catalyst requires the overpotential of 147 mV for hydrogen evolution reaction (HER). The OER and UOR half-cell reaction on V-Ni3S2 catalyst requires potential 1.57 V and 1.39 V (vs RHE), respectively to generate current 100 mA/cm2. The water electrolysis cell developed by V-Ni3S2 as both anode and cathode generates 100 mA/cm2 at cell voltage of 1.88 V in laboratory condition (1M KOH, 25°C) and 1.61 V at industrial condition (5M KOH, 80°C) and also shows considerable stability for 82hr at current 300 mA/cm2. The urea electrolysis cell with 1M KOH and 0.33 M urea generates 100 mA/cm2 at a cell voltage of 1.73 V, which is 150 mV less than that required for water electrolysis and demonstrate stability for 85hr at a current of 100 mA/cm2.

N-doped one-dimensional carbon framework embedded with CoSe2 nanoparticles as superior electrode for advanced sodium ion storage

Cobalt selenide (CoSe2) is acknowledged as a negative electrode material for sodium-ion batteries (SIBs) due to its high theoretical capacity. However, the significant volume change and inadequate electrochemical performance during charge and discharge processes have limited its practical use in batteries. In this investigation, a straightforward and practical electrospinning method combined with selenization reaction was utilized to fabricate CoSe2 nanoparticles enclosed in nitrogen-doped carbon nanofibers with a three-dimensional self-supporting network structure (CoSe2/N-PCNFs).The CoSe2/N-PCNFs electrode has self-supporting and high conductivity properties, as an anode material for sodium-ion batteries, the discharge capacity of the composite material can reach 450.1 mAh/g after 100 cycles at a current density of 0.2 A/g, and can still maintain a large discharge capacity of 396.9 mAh/g after 500 cycles at a high current density of 1 A/g. The outstanding electrochemical performance is mainly attributed to the superior specific surface area, controllable porous structure, and high pore volume of CoSe2/N-PCNFs Experimental and density functional theory calculations both indicate that the heterojunction interface between CoSe2 and nitrogen-doped carbon can not only promote the adsorption of Na+, but also facilitate electron transfer to significantly improve the rate capability of the material.

Anchoring Ni(OH)2-CeOx Heterostructure on FeOOH-Modified Nickel-Mesh for Efficient Alkaline Water-Splitting Performance with Improved Stability under Quasi-Industrial Conditions.

Developing low-cost and industrially viable electrode materials for efficient water-splitting performance and constructing intrinsically active materials with abundant active sites is still challenging. In this study, a self-supported porous network Ni(OH)2-CeOx heterostructure layer on a FeOOH-modified Ni-mesh (NiCe/Fe@NM) electrode is successfully prepared by a facile, scalable two-electrode electrodeposition strategy for overall alkaline water splitting. The optimized NiCe0.05/Fe@NM catalyst reaches a current density of 100 mA cm-2 at an overpotential of 163 and 262mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively, in 1.0m KOH with excellent stability. Additionally, NiCe0.05/Fe@NM demonstrates exceptional HER performance in alkaline seawater, requiring only 148mV overpotential at 100mA cm-2. Under real water splitting conditions, NiCe0.05/Fe@NM requires only 1.701V to achieve 100mA cm-2 with robust stability over 1000h in an alkaline medium. The remarkable water-splitting performance and stability of the NiCe0.05/Fe@NM catalyst result from a synergistic combination of factors, including well-optimized surface and electronic structures facilitated by an optimal Ce ratio, rapid reaction kinetics, a superhydrophilic/superaerophobic interface, and enhanced intrinsic catalytic activity. This study presents a simple two-electrode electrodeposition method for the scalable production of self-supported electrocatalysts, paving the way for their practical application in industrial water-splitting processes.

Surface modification of a biomass-derived self-supported carbon nano network as an emerging platform for advanced field emitter devices and supercapacitor applications.

Herein, a self-supported carbon network is designed through the sole pyrolysis of Carica papaya seeds (biomass) without any activation agent, demonstrating their field emission and supercapacitor applications. The pyrolysis of seeds in an argon atmosphere leads to the formation of interconnected, rod-like structures. Furthermore, the hydrofluoric acid treatment not only removed impurities, but also resulted in the formation of CaF2 nanocrystals with the addition of F-doping. From the field emission studies, the turn-on field values defined at an emission current density of ∼10 μA cm-2 were found to be ∼2.16 and 1.21 V μm-1 for the as-prepared carbon and F-doped carbon, respectively. Notably, F-doped carbon exhibits a high emission current density of ∼9.49 mA cm-2 and has been drawn at an applied electric field of ∼2.29 V μm-1. Supercapacitor studies were carried out to demonstrate the multi-functionality of the prepared materials. The F-doped carbon electrode material exhibits the highest specific capacitance of 234 F g-1 at 0.5 A g-1. To demonstrate the actual supercapacitor application, the HFC//HFC symmetric coin cell supercapacitor device was assembled. The overall multifunctional applicability of the fabricated hybrid structures provides a futuristic approach to field emission and energy storage applications.

Realizing ampere-level CO2 electrolysis at low voltage over a woven network of few-atom-layer ultralong silverene nanobelts with ultrahigh aspect ratio by pairing with formaldehyde oxidation.

The development of advanced multi-functional electrocatalysts and their industrial operation on paired electrocatalysis systems presents a promising avenue for the gradual penetration of renewable energy into practical production. Herein, a self-supported conductive network of silverene nanobelts (Ag-ene NBs) was delicately assembled (Ag-NB-NWs), in which ultralong and few-atom-layer Ag-ene NBs with a high edge-to-facet ratio were interconnected, serving as "superreactors" for electron transfer and mass transport during the reaction. Such superstructures as electrocatalysts delivered an unparalleled performance toward the CO2-to-CO conversion with exclusively high faradaic efficiency (FE) and partial current densities of up to 1 A cm-2. Remarkably, the membrane electrode assembly (MEA) cell with Ag-NB-NWs as the cathode was capable of ultrastable and continuous operation for over 240 h at 0.4 A with ∼100% selectivity. More importantly, by further using Ag-NB-NWs as a bifunctional electrocatalyst, a record-low voltage overall CO2 electrolysis system coupling cathodic CO2 reduction with anodic formaldehyde oxidation in MEA cell was performed to achieve concurrent feed gas generation and formate production, substantially improving electrochemical techno-economic feasibility.

A hybrid approach to oil structuring - combining wax oleogels and capillary suspensions.

There is continuing interest in finding new approaches to gel liquid oil for processed food applications. Here, we combined oleogels and capillary suspensions to generate model oil-continuous networks consisting of a wax oleogel and a water-bridged, glass particle network. The composition map tested comprised 30 vol% polar or non-polar glass beads dispersed in a 70 vol% non-particle phase consisting of water (≤9 vol%) as well as 2 wt% hexatriacontane as oleogelator in canola oil. While the hexatriacontane wax alone gelled the oil, presence of the glass beads (but no water) prevented oleogelation. Self-supporting capillary networks formed with polar particles and 1 vol% water or non-polar glass beads and 3 vol% water in canola oil. The capillary suspensions demonstrated significant differences in rheological behaviour as the polar particles yielded much higher elastic moduli than their non-polar particle counterparts. Polar hybrids were weakened by inclusion of the wax whereas the non-polar particle hybrid network displayed elastic moduli greater than the respective contributions of both capillary and wax gel networks. This hybrid method of oleogelation can be applied to virtually any food particles and uses minimal water and wax.

Advanced Synthetic Scaffolds Based on 1D Inorganic Micro-/Nanomaterials for Bone Regeneration.

Inorganic nanoparticulate biomaterials, such as calcium phosphate and bioglass particles, with chemical compositions similar to that of the inorganic component of natural bone, and hence having excellent biocompatibility and bioactivity, are widely used for the fabrication of synthetic bone graft substitutes. Growing evidence suggests that structurally anisotropic, or 1D inorganic micro-/nanobiomaterials are superior to inorganic nanoparticulate biomaterials in the context of mechanical reinforcement and construction of self-supporting 3D network structures. Therefore, in the past decades, efforts have been devoted to developing advanced synthetic scaffolds for bone regeneration using 1D micro-/nanobiomaterials as building blocks. These scaffolds feature extraordinary physical and biological properties, such as enhanced mechanical properties, super elasticity, multiscale hierarchical architecture, extracellular matrix-like fibrous microstructure, and desirable biocompatibility and bioactivity, etc. In this review, an overview of recent progress in the development of advanced scaffolds for bone regeneration is provided based on 1D inorganic micro-/nanobiomaterials with a focus on their structural design, mechanical properties, and bioactivity. The promising perspectives for future research directions are also highlighted.

Development of high internal phase emulsions with noncovalent crosslink of soy protein isolate and tannic acid: Mechanism and application for 3D printing.

In this study, we propose a design strategy using soy protein isolate (SPI)-tannic acid (TA) complexes crosslinked through noncovalent interactions to develop high internal phase emulsions (HIPEs) for 3D printing materials. The results of Fourier transform infrared spectroscopy, intrinsic fluorescence, and molecular docking analyses indicated that the dominant interactions occurring between the SPI and TA were mediated by hydrogen bonds and hydrophobic interactions. The secondary structure, particle size, ζ-potential, hydrophobicity and wettability of SPI was significantly altered by the addition of TA. The microstructure of HIPEs stabilized by SPI-TA complexes exhibited more regular and even polygonal shapes, thereby allowing the protein to form a dense self-supporting network structure. When the concentration of TA exceeded 50μmol/g protein, the formed HIPEs remained stable after 45days of storage. Rheological tests revealed that the HIPEs exhibited a typical gel-like (G'>G'') and shear-thinning behavior, which contributed to preferable 3D printing behavior.

High-performance flexible energy storage: Decorating wrinkled MXene with in situ grown Cu2O nanoparticles

The precise design and fabrication of electrode materials is important for the development of high-performance flexible supercapacitors. Cu2O/MXene film electrodes with an interconnected conductive network structure are prepared in this work by in situ growth of Cu2O nanoparticles in a Ti3C2Tx dispersion, followed by alkali induction and vacuum filtration. The interconnected crimpled Ti3C2Tx structure produced by alkali induction not only works as the self-supported conductive network of the thin film electrode but also demonstrates sufficient open pores and high surface area, which can promote electrolyte penetration and increase active sites for energy storage. The synergy between Cu2O nanoparticles and the crimpled Ti3C2Tx framework leads to good structural stability and electrochemical performance. The results show that the Cu2O/MXene electrode exhibits a high specific area capacitance of 1518 mF cm−2 in 1 M LiCl electrolyte. In addition, the all-solid-state flexible supercapacitor fabricated with the Cu2O/MXene electrode exhibits excellent cyclic stability and flexibility; the capacity retains 94.3% after 10,000 charge and discharge cycles, and the energy storage performance remains stable after 50 mechanical bending cycles.

Simple Synthesis of AuPd Aerogel as a Self-Supporting Electrocatalysts with Excellent Performance

Direct ethanol fuel cell (DEFC) has the advantages of low pollution emissions, easy to carry, and high energy density. However, the development of fuel cells is limited due to the low catalytic activity and poor stability of electrode catalyst materials. Precious metal aerogels not only have three-dimensional self-supporting network structures but also have excellent properties of precious metals, which have very good catalytic efficiency for ethanol. In this study, bimetallic aerogels with varying Au/Pd ratios were prepared, and their impact on the electrocatalytic performance of ethanol was investigated.

Acquisition of insoluble soybean fiber with high gelation performance based on structural modifications through pH-shifting during steam-cooking treatment

Utilization of by-products remains a critical technical challenge in the food industry. This work aimed to improve the gelation performance of insoluble soybean fiber (ISF) from okara based on structural modifications via pH-shifting during steam-cooking treatment. Okara was intrinsically compact and tightly aggregated. Its amorphous region was degraded by steam-cooking at pH 3 and inter-molecular H-bonds were reduced, resulting in increased content of cellulose from 37.86 wt% to 43.32 wt% and crystallinity degree from 7.79% to 40.10%. The compact structure of okara was dissociated into flexible fibers by steam-cooking at pH 11, allowing for higher porosity with a specific surface area reaching 1.4428 m2/g. However, there were no significant changes in microstructure except for a decreased particle size as pH approached neutral. The outstanding structure and adsorption capacity of ISF supported the higher gelatin performance. The hydrogels with a self-supporting and dense network structure were observed after continuous stirring from ISF steam-cooked at pH 3, 4, and 11, which was attributed to H-bonds between ISFs, while okara and other ISF suspensions exhibited good fluidity. These findings provide a new method for ISF treated by steam-cooking to enable hydrogel formation for potential applications in reconstituted foods and low-calorie gel systems.

Baking using oleogels

Baking using oleogels

Investigation of the Photocatalytic Hydrogen Production of Semiconductor Nanocrystal-Based Hydrogels.

Destabilization of a ligand-stabilized semiconductor nanocrystal solution with an oxidizing agent can lead to a macroscopic highly porous self-supporting nanocrystal network entitled hydrogel, with good accessibility to the surface. The previously reported charge carrier delocalization beyond a single nanocrystal building block in such gels can extend the charge carrier mobility and make a photocatalytic reaction more probable. The synthesis of ligand-stabilized nanocrystals with specific physicochemical properties is possible, thanks to the advances in colloid chemistry made in the last decades. Combining the properties of these nanocrystals with the advantages of nanocrystal-based hydrogels will lead to novel materials with optimized photocatalytic properties. Thisworkdemonstrates that CdSe quantum dots, CdS nanorods, and CdSe/CdS dot-in-rod-shaped nanorods as nanocrystal-based hydrogels can exhibit a much higher hydrogen production rate compared to their ligand-stabilized nanocrystal solutions. The gel synthesis through controlled destabilization by ligand oxidation preserves the high surface-to-volume ratio, ensures the accessible surface area even in hole-trapping solutions and facilitates photocatalytic hydrogen production without a co-catalyst. Especially with such self-supporting networks of nanocrystals, the problem of colloidal (in)stability in photocatalysis is circumvented. X-ray photoelectron spectroscopy and photoelectrochemical measurements reveal the advantageous properties of the 3D networks for application in photocatalytic hydrogen production.

Creating an atlas of the bone microenvironment during oral inflammatory-related bone disease using single-cell profiling.

Oral inflammatory diseases such as apical periodontitis are common bacterial infectious diseases that may affect the periapical alveolar bone tissues. A protective process occurs simultaneously with the inflammatory tissue destruction, in which mesenchymal stem cells (MSCs) play a primary role. However, a systematic and precise description of the cellular and molecular composition of the microenvironment of bone affected by inflammation is lacking. In this study, we created a single-cell atlas of cell populations that compose alveolar bone in healthy and inflammatory disease states. We investigated changes in expression frequency and patterns related to apical periodontitis, as well as the interactions between MSCs and immunocytes. Our results highlight an enhanced self-supporting network and osteogenic potential within MSCs during apical periodontitis-associated inflammation. MSCs not only differentiated toward osteoblast lineage cells but also expressed higher levels of osteogenic-related markers, including Sparc and Col1a1. This was confirmed by lineage tracing in transgenic mouse models and human samples from oral inflammatory-related alveolar bone lesions. In summary, the current study provides an in-depth description of the microenvironment of MSCs and immunocytes in both healthy and disease states. We also identified key apical periodontitis-associated MSC subclusters and their biomarkers, which could further our understanding of the protective process and the underlying mechanisms of oral inflammatory-related bone disease. Taken together, these results enhance our understanding of heterogeneity and cellular interactions of alveolar bone cells under pathogenic and inflammatory conditions. We provide these data as a tool for investigators not only to better appreciate the repertoire of progenitors that are stress responsive but importantly to help design new therapeutic targets to restore bone lesions caused by apical periodontitis and other inflammatory-related bone diseases.

Self-supporting network-structured MoS2/heteroatom-doped graphene as superior anode materials for sodium storage.

Layered graphene and molybdenum disulfide have outstanding sodium ion storage properties that make them suitable for sodium-ion batteries (SIBs). However, the easy and large-scale preparation of graphene and molybdenum disulfide composites with structural stability and excellent performance face enormous challenges. In this study, a self-supporting network-structured MoS2/heteroatom-doped graphene (MoS2/NSGs-G) composite is prepared by a simple and exercisable electrochemical exfoliation followed by a hydrothermal route. In the composite, layered MoS2 nanosheets and heteroatom-doped graphene nanosheets are intertwined with each other into self-supporting network architecture, which could hold back the aggregation of MoS2 and graphene effectively. Moreover, the composite possesses enlarged interlayer spacing of graphene and MoS2, which could contribute to an increase in the reaction sites and ion transport of the composite. Owing to these advantageous structural characteristics and the heteroatomic co-doping of nitrogen and sulfur, MoS2/NSGs-G demonstrates greatly reversible sodium storage capacity. The measurements revealed that the reversible cycle capacity was 443.9 mA h g-1 after 250 cycles at 0.5 A g-1, and the rate capacity was 491.5, 490.5, 453.9, 418.1, 383.8, 333.1, and 294.4 mA h g-1 at 0.1, 0.2, 0.5, 1, 2, 5 and 10 A g-1, respectively. Furthermore, the MoS2/NSGs-G sample displayed lower resistance, dominant pseudocapacitive contribution, and faster sodium ion interface kinetics characteristic. Therefore, this study provides an operable strategy to obtain high-performance anode materials, and MoS2/NSGs-G with favorable structure and excellent cycle stability has great application potential for SIBs.

Pickering high internal phase emulsions with excellent UV protection property stabilized by Spirulina protein isolate nanoparticles

Herein, we reported the use of natural, renewable, and food-grade Spirulina protein isolate nanoparticles (SPI NPs) as effective particle stabilizers for Pickering high internal phase emulsions (Pickering-HIPEs). SPI NPs were prepared using a straightforward antisolvent technique and characterized using dynamic light scattering (DLS), and zeta potential measurement as well as scanning electron microscopy (SEM). SPI NPs were afterward used as sole stabilizers to prepare the oil-in-water (O/W) HIPEs, the effects of oil content, particle concentration, and pH of aqueous phase on the microstructure, stability, and rheological behaviors of the resulting Pickering-HIPEs were investigated. The Pickering-HIPEs generated showed a self-supporting gel network, a high oil content (up to 85 vol%), and extraordinary storage stability after prolonged storage and UV exposure. Concurrently, the Pickering-HIPEs provided good UV protection for a variety of photosensitive compounds, including β-carotene, vitamin E, and limonene. These findings would not only advance the development of biocompatible particle stabilizers for Pickering-HIPEs in cosmetic, food, and pharmaceutical industries, but they would also provide a guidance for the protection of photosensitive compounds.

A 3D multifunctional nitrogen-doped RGO-based aerogel with silver nanowires assisted self-supporting networks for enhanced electromagnetic wave absorption

We designed a promising three-dimensional (3D) nitrogen-doped reduced graphene oxide-based aerogel (NGA) with silver nanowires (Ag NWs) assisted self-supporting networks for enhanced electromagnetic wave (EMW) absorption. 3D AgNWs@NGAs (8–12 mg/mL) were synthesized by a three-step strategy of sonication, reduction, and lyophilization. The results show that introduced sp3 defects and disordered sites in nitrogen doping from a rarely-reported liquid nitrogen source of acetonitrile remarkably improved electronic dipole polarization relaxation and EMW absorption ability. Besides, electronic band structure and density of states of the NGA were investigated by first-principles calculations to indicate that the carrier mobility became smaller during nitrogen doping. The Ag NWs were distributed on an NGA as the 3D network structure of an elastic support and a conductive and compatible unit, which limited the aggregation of NGA flakes, and further strengthened conductive loss. Significantly, the synthesized ultralight AgNWs@NGA exhibits excellent performance at 9.52 GHz, with a strong minimal reflection loss of –79.99 dB, a small thickness of 2.660 mm, a wide effective absorption bandwidth of 3.5 GHz, and an ultra-low filler content of 5 wt%. Furthermore, a large specific surface of 331.5 cm3/g, a good conductivity of approximately 50 S/cm, a high resilience, and an excellent heat insulation capability, guarantee the durable stability in EMW absorption of AgNWs@NGAs to resist distortion and heat attacks.

Ultrasmall Gold Nanoclusters-Enabled Fabrication of Ultrafine Gold Aerogels as Novel Self-Supported Nanozymes.

Metal aerogels represent an emerging type of functional porous materials with promising applications in diverse fields, but the fabrication of metal aerogels with specific structure and property still remains a challenge. Here, the authors report a new approach to fabricate metal aerogels by using ultrasmall metal nanoclusters (NCs) as functional building blocks. By taking D-penicillamine-stabilized gold NCs (AuNCs) with a diameter of 1.4nm as an example, Au aerogels with ultrafine ligament size (3.5nm) and good enzyme-mimic properties are synthesized. Detailed characterization shows that the obtained Au aerogels possess typical 3D self-supported porous network structure with high gold purity and surface area. Time-lapse spectroscopic and microscopic monitoring of the gelation process reveal that these ultrasmall AuNCs first grow into large nanoparticles before fusion into nanowire networks, during which both pH and the precursor concentration are identified to be the determining factor. Owing to their highly porous structure and abundant metal nodes, these self-supported Au aerogels display excellent peroxidase-like properties. This work provides a strategy for fabricating advanced metal aerogels by taking ultrasmall-sized metal NCs as building blocks, which also opens new avenues for engineering the structure and properties of metal aerogels for further advancing their applications.

Peanut Protein Microgels Self-Assembling, Self-Depolymerizing at Oil/Water Interface and Form a Self-Supporting Network to Stabilize the Pickering Emulsion

Peanut Protein Microgels Self-Assembling, Self-Depolymerizing at Oil/Water Interface and Form a Self-Supporting Network to Stabilize the Pickering Emulsion

Tunable Hollow Nanoreactors for In Situ Synthesis of GeP Electrodes towards High-Performance Sodium Ion Batteries.

The practical application of germanium phosphide (GeP) in battery systems is seriously impeded referring to the sluggish reaction kinetics and severe volume change. Nanostructure design that elaborately resolves the above issues is highly desired but still remains a big challenge. Herein, unique hollow nanoreactors assembled with nitrogen-doped carbon networks for in situ synthesis of the GeP electrodes are proposed for the first time. Such nanoreactors form a self-supported conductive network, ensuring sufficient electrolyte infiltration and fast electron transport. They restrain crystal growth and accommodate the volume expansion of GeP simultaneously. Reaction kinetics and confinement effect are optimized through nanoreactor size regulation. The optimized GeP electrode has high reversible capacities and outstanding cyclability and rate performance for sodium storage, outperforming most previously reported phosphides.