Three-dimensional Porous Structure Research Articles

In vitro digestion of starch and protein aerogels generated from defatted rice bran via supercritical carbon dioxide drying

This study investigated the in vitro digestibility of starch and protein aerogels produced from defatted rice bran (DRB), an underutilized rice processing byproduct, using supercritical carbon dioxide (SC-CO2) drying. The extracted starch (i.e., purified starch), crude starch, and proteins were used for the aerogel formation at 15% (w/w) concentration and further characterized. All aerogels exhibited three-dimensional open porous structures with high surface areas of 36–47 m2/g, densities lower than 0.3 g/cm3, and porosities higher than 84%. The starch hydrolyses in starch and crude starch aerogels were 86 and 73%, respectively, while the protein hydrolysis in protein aerogels reached up to 82% after sequential oral, gastric, and intestinal digestion. Thus, the hydrolysis rates achieved in simulated digestions suggest that the developed aerogels from DRB have the potential to serve as vehicles for delivering bioactive compounds and add value to the underutilized DRB.

Water-triggered shape memory cellulose / sodium alginate / montmorillonite composite sponges for rapid hemostasis

Uncontrollable bleeding caused by severe trauma is life-threatening. Therefore, it is of great significance to develop hemostatic materials that meet the rapid hemostasis of wounds. In this study, a water-triggered shape memory carboxylated cellulose nanofiber/sodium alginate/montmorillonite (CNSAMMTCa) composite hemostatic sponge was prepared, which can promote coagulation by concentrating the blood and activating intrinsic pathway. The anisotropic three-dimensional porous structure formed by directional freeze-drying technology improved the performance of composite sponges which showed good prospects in rapid hemostasis. The results showed that CNSAMMTCa composite sponge had good porous structure, water absorption ability, cytocompatibility and blood cell aggregation capacity. Simultaneously, we confirmed that CNSA3MMT2Ca has best coagulation performance in the mouse censored bleeding model and liver rupture bleeding model. Therefore, CNSAMMTCa composite hemostatic sponge is a safe and efficient rapid hemostatic material which is expected to become an alternative material for clinical hemostatic materials.

Engineering the Integration of Titanium and Nickel into Zinc Oxide Nanocomposites through Nanolayered Structures and Nanohybrids to Design Effective Photocatalysts for Purifying Water from Industrial Pollutants

Water pollution is one of the main challenges currently facing scientists around the world because of the rapid growth in industrial activities. On this basis, 2D nanolayered and nanohybrid structures, which are based on a ternary system of nickel–titanium–zinc, are considered favorable sources for designing effective nanocomposites for the photocatalytic degradation of industrial pollutants in a short period of time. These nanocomposites were designed by modifying two-dimensional nanolayers to produce a three-dimensional porous structure of multi-doped Ni/Ti-ZnO nanocomposites. Additionally, another additive was produced by constructing nanohybrids of nickel–titanium–zinc combined with a series of hydrocarbons (n-capric acid, myristic acid, stearic acid, suberic acid, and sebacic acid). Energy-dispersive X-ray spectrometry, X-ray diffraction, scanning electron microscopy, infrared spectroscopy, and thermal analyses confirmed the growth of the nanolayered and nanohybrid materials in addition to the production of nanocomposites. The positive role of the dopants (nickel and titanium) in producing an effective photocatalyst was observed through a significant narrowing of the band gap of zinc oxide to 3.05–3.10 eV. Additionally, the high photocatalytic activity of this nanocomposite enabled the complete removal of colored dye from water after 25 min of UV radiation. In conclusion, this study proposes an unconventional approach for designing new optical nanocomposites for purifying water. Additionally, it suggests a novel supporting method for designing new kinds of nanohybrids based on multi-metals and organic acids.

Covalent crosslinking tetraethylenepentamine/cellulose composite aerogels with adsorbability for dye elimination

The cellulose-biomass material possesses a distinctive structure, distinguished by its eco-friendliness, degradability, renewability, cost-effectiveness, and efficacy as a bio-absorbent. In this groundbreaking study, we synthesized cellulose aerogels for the first time using a combination of sol-gel processing, straightforward chemical crosslinking, and freeze-drying. The functionalized materials exhibit an intricately interconnected three-dimensional porous structure achieved through covalent crosslinking with tetraethylenepentamine (TEPA). The resulting aerogel demonstrated a highly porous structure (exceeding 90%), low density (91.89–114.87 mg/cm3), and abundant surface amine groups advantageous for removing organic dyestuffs. To comprehensively assess the impact of the fabricated aerogel on methylene blue and crystal violet adsorption behavior, a detailed investigation was conducted, considering variables such as cellulose content (1.0–3.0 wt%), TEPA/EtOH/H2O volume ratio (1.0–3.0/5.0/3.0), contact time (0–300 min), and initial dye concentration (25–200 mg/L). As a result, the nitrogen-rich aerogel (with 2 wt% cellulose and TEPA/EtOH/H2O ratio of 2.0/5.0/3.0) exhibited dye adsorption following a pseudo-second-order kinetic model, with adsorption isotherms aligning with the Freundlich model. Thermodynamic assessments indicated that the adsorption process is a spontaneous endothermic reaction. Consequently, these eco-friendly cellulose sponges emerge as promising adsorbents for effective wastewater treatment, highlighting their potential as a sustainable solution in environmental remediation.

Preparation and properties of asymmetric inverse opal-like microfiltration membranes

Most types of commercially available MF membranes suffer limited separation performances due to huge deviations in pore size and low porosity. In view of this, a new and facile assembly strategy was proposed to prepare an asymmetric inverse opal (IO) like microfiltration (MF) membrane with ordered pore structure, high porosity and large water flux, which is a composite of a disordered layer with three-dimensional pore structures made by dissolved N, N-dimethylformamide (DMF) and an ordered layer with uniform pore size by using a sacrificial template method. The effects of SiO2 microsphere size and DMF treatment on the structure and properties have been investigated. Different DMF treatment times can significantly change the asymmetric structure distribution of MF membrane and further affect the permeability. The water flux of the asymmetric membrane increases with the DMF infiltration time. Based on the SiO2 microsphere template size of 494 nm and the DMF treatment time of 90 s, the porosity and pure water flux can reach 78 % and 1810 L/m2h, respectively. The membrane retains the IO-like structure layer with uniform pore size, and features excellent retention (almost 100 %) for SiO2 microspheres, indicating the great potential of asymmetric IO-like MF membranes for membrane separation applications.

Advancing carbon dioxide capture: Unravelling structure-property-performance dynamics in graphene related two-dimensional materials

Efficient design of adsorbents for carbon dioxide (CO2) capture is imperative in addressing the challenges caused by climate change. In this study, a comprehensive exploration of solid adsorbents derived from graphene-related two-dimensional materials (GR2Ms) with tunable surface chemistry and structures was undertaken to unravel the intricate structural-property-activity relationships essential for optimizing their CO2 adsorption. Nine key GR2Ms and carbon materials, including two types of (few-layer graphene (FLG), graphene oxide (GO) reduced graphene oxide (rGO) materials), expanded graphite (Exp Gft), rGO-Exp Gft and graphite (Gft), were methodically characterized alongside benchmarked materials such as activated carbon (AC) and molecular sieves (MS). Characterization parameters, i.e. morphology, particle size, interlayer distance, crystallite size, defect density, specific surface area (SSA), total pore volume, micropore volume and pore size, are correlated with CO2 adsorption capacity. Results revealed that the dominant properties influencing CO2 adsorption in GR2Ms are hierarchical porous morphology, defect density (up to 2.38 × 1011 cm−2), SSA (up to ∼271 m2/g), total pore volume (up to 0.86 cm3/g), and micropore volume (up to 0.03 cm3/g), all of which have established positive linear relationships. Conversely, crystallite size (0.38–48 nm) exhibited an inverse (non-linear) relationship with CO2 adsorption capacity under ambient conditions (25 °C and 1 atm). Particle size (8–52 μm), interlayer distance (0.33–0.89 nm) and pore size (4.2–13.3 nm) of GR2Ms showed negligible impact on CO2 adsorption capacity. Remarkably, porous rGO emerged as the top-performing CO2 adsorbent with an enhanced adsorption capacity (5.38 mmol/g) , in comparison with activated carbon (AC, 1.79 mmol/g) and molecular sieve (MS, 1.48 mmol/g). This study establishes a comprehensive structure-property-performance relationship, highlighting the significance of a three-dimensional (3D) hierarchical, open and interconnected pore structure within the graphene network, along with the largest pore volume and minimum crystallite size of rGO. These findings underscore the critical role of structural and porosity attributes of GR2Ms in CO2 adsorption, providing fundamental insights into the interplay between the structure and properties on their CO2 adsorption behavior. This study emphasizes the key pillars for effective adsorbent design and underlines the necessity of optimised control over the structural characteristics and porosity of GR2Ms to enhance their CO2 adsorption capabilities, contributing towards the ambitious net-zero target by 2050.

Facile preparation of cellulose nanofiber/ZSM-5 zeolite/polyethyleneimine aerogel for selective adsorption of Cu2+ in wastewater

The development of a cost-effective and environmentally friendly adsorbent is essential for effectively removing heavy metals from wastewater. This study presents the preparation of a recyclable cellulose nanofiber (CNF)/ZSM-5 zeolite/polyethyleneimine (PEI) aerogel through chemical crosslinking and freeze-drying techniques. The synthesized aerogel was applied for the highly selective adsorption of Cu2+. The characterization of the as-prepared aerogel indicates that its three-dimensional network porous structure, along with the abundance of active sites, contributes to the effective adsorption of Cu2+. The adsorption capacity was found to be 134.23 mg/g. Furthermore, it was observed that Cu2+ adsorbed by the composite aerogel could be efficiently eluted using 0.2 M EDTA-2Na. The adsorption kinetics and isotherm studies revealed consistency with the pseudo-second-order model and Langmuir model, indicating that the adsorption process was primarily governed by monolayer chemisorption. Mechanism analysis further confirmed that surface complexation, ion exchange, and electrostatic interaction were the primary driving forces behind the excellent adsorption capabilities of the prepared aerogel. Remarkably, the structural integrity and selective adsorption of the composite aerogel remained largely unchanged even after undergoing five sorption-desorption cycles. These findings strongly suggest that the CNF/ZEM-5/PEI composite aerogel holds significant promise for achieving efficient and selective removal of copper ions in wastewater.

In-situ forming carboxymethyl chitosan hydrogel containing Paeonia suffruticosa Andr. leaf extract for mixed infectious vaginitis treatment by reshaping the micro-biota

Mixed infectious vaginitis poses a serious threat to female reproductive health due to complex pathogenic factors, a long course and easy recurrence. Currently, antibiotic-based treatment methods are facing a crisis of drug resistance and secondary dysbiosis. Exploring effective drugs for the treatment of mixed vaginitis from Paeonia suffruticosa Andr., a natural traditional Chinese medicine with a long history of medicinal use, is a feasible treatment strategy. P. suffruticosa Andr. leaf extract (PLE) has significant anti-bacterial effects due to its rich content of polyphenols and flavonoids. The polyphenols in peony leaves have the potential to make carboxymethyl chitosan form in situ gel. In the current study, PLE and carboxymethyl chitosan were combined to develop another type of natural anti-bacterial anti-oxidant hydrogel for the treatment of mixed infectious vaginitis. Through a series of characterisations, CP had a three-dimensional network porous structure with good mechanical properties, high water absorption, long retention and a slow-release drug effect. The mixed infectious vaginitis mouse model induced by a mixture of pathogenic bacteria was used to investigate the therapeutic effects of CP in vivo. The appearance of the vagina, H&E colouring of the tissue and inflammatory factors (TNF-α, IL-6) confirm the good anti-vaginal effect of CP. Therefore, CP was expected to become an ideal effective strategy to improve mixed infection vaginitis due to its excellent hydrogel performance and remarkable ability to regulate flora.

Engineering High-Performance Li Metal Batteries through Dual-Gradient Porous Cu-CuZn Host.

Porous copper (Cu) current collectors show promise in stabilizing Li metal anodes (LMAs). However, insufficient lithiophilicity of pure Cu and limited porosity in three-dimensional (3D) porous Cu structures led to an inefficient Li-Cu composite preparation and poor electrochemical performance of Li-Cu composite anodes. Herein, we propose a porous Cu-CuZn (DG-CCZ) host for Li composite anodes to tackle these issues. This architecture features a pore size distribution and lithiophilic-lithiophobic characteristics designed in a gradient distribution from the inside to the outside of the anode structure. This dual-gradient porous Cu-CuZn exhibits exceptional capillary wettability to molten Li and provides a high porosity of up to 66.05%. This design promotes preferential Li deposition in the interior of the porous structure during battery operation, effectively inhibiting Li dendrite formation. Consequently, all cell systems achieve significantly improved cycling stability, including Li half-cells, Li-Li symmetric cells, and Li-LFP full cells. When paired synergistically with the double-coated LiFePO4 cathode, the pouch cell configured with multiple electrodes demonstrates an impressive discharge capacity of 159.3 mAh g-1 at 1C. We believe this study can inspire the design of future 3D Li anodes with enhanced Li utilization efficiency and facilitate the development of future high-energy Li metal batteries.

ZIF-67 derived CoNi@carbon/RGO composites with abundant heterogeneous interfaces for electromagnetic wave absorption

The controllable structure design and composition regulation play a key role in the development of electromagnetic wave (EMW) absorbing material. Herein, CoNi@carbon/RGO absorbing materials were successfully prepared by direct pyrolysis of ZIF-67/Ni(OH)2/GO precursor. The CoNi@carbon/RGO-15 sample achieves an RLmin value of −46.14 dB and an effective absorption bandwidth (EAB) of 1.15 GHz (thickness 4.1 mm) at a low frequency with a filling amount of only 10 wt%. When the thickness is 1.5 mm, the RLmin reaches −41.09 dB and the EAB reaches 5.41 GHz, covering most of the Ku bands. After the pyrolysis, the carbon layer, Co and Ni nanoparticles, and RGO nanosheets form a three-dimensional porous structure, which builds up abundant heterogeneous interfaces and conductive networks. These factors can enhance impedance matching, dielectric, and magnetic loss. This indicates that CoNi@carbon/RGO is the potential lightweight EMW absorbing material with high performance.

Facile synthesis of an acrylic acid-co-2-acrylamide-2-methylpropanesulfonic acid copolymer / polyvinylpyrrolidone semi-IPN hydrogel with excellent swelling and anti-leakage properties

Water scarcity becomes an increasingly serious problem for humankind due to climate change and population growth, especially the water leakage in arid and semi-arid areas. Hydrogel polymers show increasingly important roles on water resources utilization. A novel hydrogel copolymer, acrylic acid-co-2-acrylamide-2-methylpropanesulfonic acid copolymer / polyvinylpyrrolidone (P(AA-co-AMPS)/PVP) semi-interpenetrating network (semi-IPN) hydrogel, was designed and successfully synthesized via a facile one-pot free radical copolymerization method. The main parameters during the synthesis process were optimized, including relative contents of polymer monomers, cross-linking agent, initiator and neutralization agent. Physical characterizations demonstrate that, P(AA-co-AMPS)/PVP hydrogel shows porous three-dimensional network structure, including a crosslinked network structure in P(AA-co-AMPS) copolymers and their intermolecular hydrogen bonding interactions with linear PVP. The as-synthesized P(AA-co-AMPS)/PVP hydrogel not only can deliver superior water absorbing capability (up to 1689.95 g g−1) and good reswelling performance, but also shows excellent water anti-leakage performance when being composed with red clay, demonstrating its multi-role applications in future sustainable agriculture.

A novel nanosheets assembled porous fusiform Co2P2O7 for sensitive electrochemical detection of ultratrace As(III) ions

A facile and low-cost method was used to synthesize a novel nanosheets assembled porous fusiform Co2P2O7 for ultrasensitive electrochemical sensing detection of As(III) in water. The porous fusiform Co2P2O7 formed by small nanosheets exhibits a three-dimensional porous structure with a rough surface and good dispersion, facilitating a well-connected electron transfer path and providing numerous electroactive sites to bind with As(III). The proposed electrochemical sensor exhibited a high sensitivity of 91.04 µA µg/L cm−2 and a low detection limit of 0.087 µg/L towards As(III) in 0.1 M HAc-NaAc buffer (pH 5.0). Furthermore, it exhibited great potential for the electrochemical detection of As(III) in tap water.

Scleroglucan-Based Foam Incorporating Recycled Rigid Polyurethane Waste for Novel Insulation Material Production.

This study details the synthesis and performance evaluation of a novel lightweight thermal and acoustic insulation material, resulting from the combination of a scleroglucan-based hydrogel and recycled rigid polyurethane waste powder. Through a sublimation-driven water-removal process, a porous three-dimensional network structure is formed, showcasing notable thermal and acoustic insulation properties. Experimental data are presented to highlight the material's performance, including comparisons with commercially available mineral wool and polymeric foams. This material versatility is demonstrated through tunable mechanical, thermal and acoustic characteristics, achieved by strategically adjusting the concentration of the biopolymer and additives. This adaptability positions the material as a promising candidate for different insulation applications. Addressing environmental concerns related to rigid polyurethane waste disposal, the study contributes to the circular economy.

Hydrogel/MOF Dual-Modified Photoelectrochemical Biosensor for Antibiofouling and Biocompatible Dopamine Detection.

For accurate in vivo detection, nonspecific adsorption of biomacromolecules such as proteins and cells is a severe issue. The adsorption leads to electrode passivation, significantly compromising both the sensitivity and precision of sensing. Meanwhile, common antibiofouling modifications, such as polymer coatings, still grapple with issues related to biocompatibility, electrode passivation, and miniaturization. Herein, we propose a composite antibiofouling coating strategy based on zwitterionic metal-organic frameworks (Z-MOFs) and a combination of acrylamide hydrogels. On a well-designed TiO2/Z-MOF/hydrogel photoelectrode, we achieve highly sensitive and selective detection of dopamine in complex biological environments. The hydrogel's three-dimensional porous structure combined with unique microporous architecture of Z-MOF ensures effective sieving of interfering macromolecules while preserving efficient small molecules and electron transport. This innovative approach paves the way for constructing miniature, in vivo antibiofouling sensors for molecule monitoring in living organisms with complicated chemical environments.

Numerical investigation of fluid flow behavior in steel cord with lattice Boltzmann methodology: The impacts of microstructure and loading force.

Steel cord materials were found to have internal porous microstructures and complex fluid flow properties. However, current studies have rarely reported the transport behavior of steel cord materials from a microscopic viewpoint. The computed tomography (CT) scanning technology and lattice Boltzmann method (LBM) were used in this study to reconstruct and compare the real three-dimensional (3D) pore structures and fluid flow in the original and tensile (by loading 800 N force) steel cord samples. The pore-scale LBM results showed that fluid velocities increased as displacement differential pressure increased in both the original and tensile steel cord samples, but with two different critical values of 3.3273 Pa and 2.6122 Pa, respectively. The original steel cord sample had higher maximal and average seepage velocities at the 1/2 sections of 3D construction images than the tensile steel cord sample. These phenomena should be attributed to the fact that when the original steel cord sample was stretched, its porosity decreased, pore radius increased, flow channel connectivity improved, and thus flow velocity increased. Moreover, when the internal porosity of tensile steel cord sample was increased by 1 time, lead the maximum velocity to increase by 1.52 times, and the average velocity was increased by 1.66 times. Furthermore, when the density range was determined to be 0-38, the pore phase showed the best consistency with the segmentation area. Depending on the Zou-He Boundary and Regularized Boundary, the relative error of simulated average velocities was only 0.2602 percent.

Heterostructural PbO2/Co3O4 composite for anodic oxidation of phenol: An energy-efficient hybrid process

The PbO2/Co3O4 composite electrodes were synthesized using the composite co-deposition method, which involved the incorporation of Co3O4 nanoparticles into a PbO2 coating. These composite electrodes were employed as anodes for phenol electrooxidation in wastewater treatment. The results demonstrate that the PbO2/Co3O4 composite electrode exhibits a three-dimensional porous structure, leading to a significant increase in the electrochemically active surface area. Electrochemical measurements indicate that the composite electrode achieves a minimum oxygen evolution potential of 526.5 mV. Moreover, the electrode facilitates the indirect degradation of phenol, even at low voltage (0.45 V). The unique structure, improved conductivity, and enhanced surface area of the electrode contribute to its exceptional performance in phenol degradation. Additionally, this approach offers the potential for synergistic integration with other treatment methods, providing a sustainable and energy-efficient solution for removing persistent organic compounds from wastewater.

A three-dimensional BaFe11.6(ZrSm)0.2O19/rGO composite aerogel with superior microwave absorption properties

The combination of dielectric and magnetic materials can significantly improve microwave absorption properties. In this work, we introduce a novel Zr–Sm doped barium ferrite BaFe11.6(ZrSm)0.2O19, which is compounded with rGO aerogel and presents superior microwave absorption properties. The results show that the BaFe11.6(ZrSm)0.2O19/rGO composite aerogel exhibits a unique three-dimensional porous network structure which enhances the reflection and scattering of electromagnetic waves. Meanwhile, the addition of BaFe11.6(ZrSm)0.2O19 abounds the folds and defects on the surface of rGO sheet layer, generating a large amount of polarisation and relaxation. In addition, with the increase of BaFe11.6(ZrSm)0.2O19 content, the permeability gradually increases, while the dielectric constant gradually decreases. At a certain content, both of them can be well balanced to obtain high attenuation constants and great impedance matching, which regulates the wave-absorbing properties of the material. The minimum reflection loss (RLmin) of BaFe11.6(ZrSm)0.2O19/rGO composite aerogel can reach −53.17 dB at a matching thickness of 2.9 mm, and the absorption bandwidth reaches 7.04 GHz, which has been improved by 40% than pure BaFe11.6(ZrSm)0.2O19. Therefore, it is expected to be a candidate for lightweight, thin, high loss, large bandwidth microwave absorbing materials.

A Large-Scale and Low-Cost Thermoacoustic Loudspeaker Based on Three-Dimensional Graphene Foam.

Graphene is a promising material for thermoacoustic sources due to its extremely low heat capacity per unit area and high thermal conductivity. However, current graphene thermoacoustic devices have limited device area and relatively high cost, which limit their applications of daily use. Here, we adopt a dip-coating method to fabricate a large-scale and cost-effective graphene sound source. This sound source has the three-dimensional (3D) porous structure that can increase the contact area between graphene and air, thus assisting heat to release into the air. In this method, polyurethane (PU) is used as a support, and graphene nanoplates are attached onto the PU skeleton so that a highly flexible graphene foam (GrF) device is obtained. At a measuring distance of 1 mm, it can emit sound at up to 70 dB under the normalized input power of 1 W. Considering its unique porous structure, we establish a thermoacoustic analysis model to simulate the acoustic performance of GrF. Furthermore, the obtained GrF can be made up to 44 in. (100 cm × 50 cm) in size, and it has good flexibility and processability, which broadens the application fields of GrF loudspeakers. It can be attached to the surfaces of objects with different shapes, making it suitable to be used as a large-area speaker in automobiles, houses, and other application scenarios, such as neck mounted speaker. In addition, it can also be widely used as a fully flexible in-ear earphone.

Study of boron alloying on microstructure evolution and electrocatalytic performance of self-supported Co–P@Cu immiscible alloy

In this contribution, the effects of B alloying on microstructure evolution and catalytic efficiency variation of Co–P@Cu immiscible alloy were systematically studied. The addition of B element significantly inhibited the second phase separation behavior by weakening Marangoni convection, resulting in the three-dimensional continuous porous structure of Co–P spheres. After dealloying treatment, the CCP–1B catalyst containing 1 wt% B exhibited preeminent electrocatalytic activity with low overpotential of 68 mV at 10 mA cm−2 and Cdl value of 50 mF cm−2 for HER. Combined with FESEM and XPS analysis, this remarkable catalytic performance of Co–P@Cu could be attributed to the remarkable refinement of particles size, more active sites for electron transport obtained from continuously porous structure and the obvious modulation of electronic structure of Co–P particles by B doping. Through the further DFT analysis, the redistribution of the charge density and the decrease of ΔGH* optimized the H* adsorption and desorption energies with a reduction of energy barrier, which were beneficial for the obvious improvement of catalytic performance of these self-supported phosphides catalysts.

In Situ Growth 3D GDY-NCNTs Nanocomposites for High-Performance Supercapacitors.

New binary carbon composites (GDY-NCNTs and GDY-CNTs) with a three-dimensional porous structure, which are synthesized by an in situ growth method, are adopted in this article. The GDY-NCNTs composites exhibit excellent specific capacitance performance (679 F g-1, 2 mV s-1, 139% increase compared to GDY-CNTs) and good cycling stability (with a capacity retention rate of up to 116% after 10000 cycles). The three-dimensional porous structure not only promotes ion transfer and increases the effective specific surface area to improve its specific capacitance performance but also adapts to the volume expansion and contraction during the charging and discharging process to improve its cycling stability. The presence of nitrogen doping in the carbon nanotubes of GDY-NCNTs increases the surface defects of the composites, provides more electrochemical points, and improves the surface wettability of the composites, further improving the electrochemical performance of the composites.