Surface Modification Strategy Research Articles

Engineering MXene Surface via Oxygen Functionalization and Au Nanoparticle Deposition for Enhanced Electrocatalytic Hydrogen Evolution Reaction.

MXene, a family of 2D transition metal carbides and nitrides, presents promising applications in electrocatalysis. Maximizing its large surface area is key to developing efficient non-noble-metal catalysts for the hydrogen evolution reaction (HER). In this study, oxygen-functionalized Ti3C2Tx MXene (Ti3C2Ox) is synthesized and deposited gold nanoparticles (Au NPs) onto it, forming a novel composite material, Au-Ti3C2Ox. By selectively removing other functional groups, mainly -O functional groups are retained on the surface, directing electron transfer from Au NPs to MXene due to electronic metal-support interaction (EMSI), thereby improving the catalytic activity of the MXene surface. Additionally, the interaction between Au NPs and -O functional groups further enhanced the overall catalytic activity, achieving an overpotential of 62 mV and a Tafel slope of 40.1 mV dec-1 at a current density of -10 mA cm-2 in 0.5 m H2SO4 solution. Density functional theory calculations and scanning electrochemical microscopy with ≤150 nm resolution confirmed the enhanced catalytic efficiency due to the specific interaction between Au NPs and Ti3C2Ox. This work provides a surface modification strategy to fully utilize the MXene surface and enhance the overall catalytic activity of MXene-based catalysts.

Surface functionalizing for high‐temperature ceramic fuel cells using electrochemical deposition technique

AbstractElectrochemical deposition technique, a method widely recognized for its precision and versatility in the electronics industry, is gaining attraction in the energy field, particularly in developing solid oxide fuel cells (SOFCs). Its ability to deposit metal compounds with nanostructures under simple ambient conditions makes it invaluable for modifying conventional electrodes with refined morphologies and compositions. In this mini‐review, we explore the principles of electrochemical deposition and highlight its recent applications in SOFC technology. Our focus lies on its pivotal role in fabricating coating layers or catalysts on electrodes with improved functionalities to build more efficient and durable fuel cells. Furthermore, we discuss emerging strategies for electrode surface modification and the potential of electrochemical deposition in advancing SOFC design and functionality. Our review also outlines future research directions aimed at harnessing and expanding the capabilities of electrochemical deposition in energy conversion applications.

Complementary Machining – Machining Strategy for Surface Modification: A Review

All fabrication techniques utilized to manufacture metallic parts modify the surface integrity of the part. Complementary machining is a relatively recent machining strategy characterized by combining metal cutting and mechanical surface treatment. Typically, it implies that after conventional machining, the cutting insert is used reversely to modify the surface by local plastic deformation. To improve product performance, mechanical surface treatment is an additional phase in the manufacturing process chain that usually results in longer production times and higher costs. As a result, a variety of hybrid techniques have been created, such as complementary machining, which has the benefit of using conventional machine tools and their associated cutting tools. The study on complementary machining is reviewed in the article. The main focus is to assess the viability of complementary machining to modify surface integrity for enhanced properties by specifically establishing its effect on tool wear, surface roughness, microhardness, fatigue, microstructure, and residual stress state.

Fabrication of an Antibacterial/Anticoagulant Dual-Functional Surface for Left Ventricular Assist Devices via Mussel-Inspired Polydopamine Chemistry.

Infections and thrombosis remain unsolved problems for implanted cardiovascular devices, such as left ventricular assist devices. Hence, the development of surfaces with improved blood compatibility and antimicrobial properties is imperative to reduce complications after artificial heart implantation. In this work, we report a novel approach to fabricate multifunctional surfaces for left ventricular transplanted ventricular assist devices (LVADs) by immobilizing nitric oxide (NO) generation catalysts and heparin and reducing silver nanoparticles in situ. The general view, structure, and chemical compositions of the pure/modified surfaces were characterized using digital imaging, scanning electron microscope (SEM), atomic force microscope (AFM), water contact angle (WCA), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma (ICP). All of the results demonstrated that the AgNPs and heparin were successfully immobilized on the surface. The Cu ions and NO release experimental results showed that the immobilized copper ions could catalyze the production of NO from S-nitrosothiols within the biological system. Meanwhile, due to the synergistic anticoagulant effect of NO and surface-immobilized heparin, the fabricated modified surfaces exhibited antiplatelet adhesion activities and good hemocompatibility. Finally, the antimicrobial activity of the samples was evaluated by Escherichia coli and Staphylococcus aureus, and cytocompatibility was measured using human umbilical vein endothelial cells (HUVECs). The results demonstrated that silver nanoparticles (AgNPs) immobilized by surface reduction reaction did not cause any significant inhibition of cell proliferation while providing stable and effective antimicrobial properties. We envision that this simple surface modification strategy with bifunctional activities of antimicrobial and anticoagulant will find widespread use in clinically used indwelling left ventricular assist devices.

Boron/Difluoroamino (B/NF2) Composites Prepared Through an Energetic Fluorinated-Centerd Surface Modification Strategy to Enhance Their Ignition and Combustion Characteristics

To enhance the ignition and combustion characteristics of boron (B), in this study, a suitable, energetic fluorinated group (NF2) that can improve energy and promote combustion efficiency was utilized and B/NF2 composites (B/PDB) with three different particle sizes (10–20 μm, <5 μm, and 0.5–2 μm) were prepared through energetic fluorinated surface modifications with a PDB layer, a copolymer of difluoroaminomethyl-3-methylethoxybutane and 3,3′-bis(azidomethyl)oxetane, coated on the surface of B. The morphology and structure of B/PDB were characterized via the FTIR, SEM, TEM, and XPS techniques. The results indicate that all B/PDB particle sizes were successfully coated by NF2 on the surfaces of B particles through the PDB layer. The TG curves in the thermal analyses were used to determine the amount of the PDB layer of B/PDB with different particle sizes. Based on the DSC curves, NF2 of composites with better catalysis during ammonium perchlorate (AP) decomposition. Additionally, the effects of NF2 on both B/PDB and B/PDB with AP were investigated through PY-GC/MS, ignition, and combustion. Compared with pure B, NF2 significantly improved the thermal conductivity, thereby decreasing the ignition delay of B/PDB, and the ignition delay of B/PDB with AP. The combustion of B/PDB and AP was more intense, extending the combustion duration, forming volatile fluorine compounds, and increasing combustion reaction efficiency. In general, this energetic fluorinated-centred surface modification has potential applications to enhance the ignition and combustion characteristics in B.

Biomimetic fucoidan nanoparticles with regulation of macrophage polarization for targeted therapy of acute lung injury

Acute lung injury (ALI) is a complex acute respiratory illness with a high mortality rate. Reactive oxygen species (ROS) play a pivotal role in ALI, inducing cellular damage, inflammation, and oxidative stress, thereby exacerbating the severity of the injury. In this study, inspired by the “subtractive” strategy, we developed a fucoidan-based macrophage membrane bio-nanosystem, abbreviated as MF@CB, designed as an anti-inflammatory and antioxidant agent to alleviate lipopolysaccharide (LPS)-induced inflammation in ALI. MF@CB coated with macrophage membrane for effective targeting and accumulation in ALI lesions. In addition, MF@CB activates Nrf2 transcriptional activity in macrophages, inhibiting ROS synthesis at its origin while effectively removing ROS already present in the ALI. This dual-pronged approach demonstrates robust antioxidant properties and restores the macrophage antioxidant defense barrier. In the LPS-induced ALI mouse model, MF@CB significantly mitigated lung inflammatory damage by modulating lung macrophage polarization and inhibiting the over-secretion of pro-inflammatory cytokines by activated immune cells. More importantly, unlike most surface modification strategies because it remove the molecule, this approach is easier to apply and potentially safer and may provide useful insights into the development of more effective therapeutic strategies for ALI.

Surface iron concentration gradient: A strategy to suppress Mn3+ Jahn-Teller effect in lithium manganese iron phosphate

To address the low energy density of LiFePO4 (LFP) for electric vehicles and high-voltage energy storage, LiMn0.5Fe0.5PO4 (LMFP) provides a potential solution but faces performance degradation due to Mn3+-induced Jahn-Teller distortion and Mn ion dissolution during cycling. This study proposes a surface engineering strategy to enhance LMFP’s electrochemical performance by increasing surface iron concentration and reducing manganese content, based on the electronic differences between Mn3+ and Fe3+ in MO6 octahedra. Density Functional Theory (DFT) calculations confirmed the viability of this approach by analyzing volume changes and binding energies with HF during charging. Guided by DFT, an LMFP@LFP/C material was synthesized with a high-iron-concentration surface layer (∼2 nm), as observed through AC-STEM. Post-cycling TEM analysis and corrosion simulations demonstrated that LMFP@LFP/C suppresses Mn ion dissolution and stabilizes the crystal lattice compared to unmodified LMFP/C. Electrochemical tests showed that LMFP@LFP/C has superior electronic conductivity and faster lithium-ion diffusion. It delivered an initial discharge capacity of 150.82 mAh g−1 at 0.1C, surpassing LMFP/C (147.65 mAh g−1). At 1C, LMFP@LFP/C retained 95.85 % of its capacity after 500 cycles, significantly outperforming LMFP/C (74.18 %). This surface modification strategy advances phosphate-based cathode materials for electric vehicles and renewable energy applications.

Dual layer-coating of PDMS to prevent calcification and bacterial infection for the potential use of urinary tract biomaterials

Polydimethylsiloxane (PDMS) is widely used in medical devices because of its exceptional properties. However, challenges, such as biofouling and bacterial infections, arise from their hydrophobic nature, especially in devices intended for the urinary tract. To address these issues, this study pioneered a surface modification strategy aimed at enriching PDMS with both hydrophilicity and antifouling attributes, making it ideal for urinary tract device applications. We introduced a novel dual-layer coating process, initially grafting a hydrogel-like poly(acrylic acid) (PAA) layer onto PDMS through benzophenone-mediated photoinitiated polymerization to enhance surface hydrophilicity. Subsequently, polyethyleneimine (PEI) was covalently bonded to the PAA layer, ensuring the formation of a stable antifouling surface that prevented bacterial adhesion and calcium deposition. This method guarantees a robust coating that performs consistently across various environmental conditions, including the fluctuating pH levels typical of the urinary tract. Comprehensive surface characterization validated the substantial improvements in hydrophilicity along with significant reductions in bacterial adhesion and calcium deposition. The innovative PAA/PEI dual-layer coating demonstrated marked superiority over conventional uncoated and single-layer-coated PDMS samples, offering a promising solution for enhancing the safety and efficacy of PDMS-based urinary tract devices. The implications of this study extend beyond immediate applications and provide valuable insights into the domains of biomaterials and medical device engineering.

Surface-induced self-assembly of peptides turns superhydrophobic surface of electrospun fibrous into superhydrophilic one

Current surface modification strategies for electrospun materials always require covalent conjugation technology, which is relatively inefficient and might damage the bioactivity and structure of peptides and proteins. Here we introduce the use of surface-induced self-assembly technology to modify electrospun materials, which is a simple but efficient noncovalent-based process. Results show that the peptide NapFFGRGD forms burr-like structures on the surface of PCL fibers, reducing the water contact angle of the fibers. Adjusting the peptide sequence and salt concentration affects the self-assembly and surface properties of modified PCL fibers. Additionally, we demonstrate the potential application of this surface modification technique for enhancing cellular responses in tissue engineering applications. The research provides valuable insights into the surface modification of PCL fibers and offers a new method for improving the biological compatibility of materials in tissue engineering.

General Approach to Hydrolysis Resistive Aluminum Nitride and Its High-Performance Thermal Interface Materials.

Aluminum nitride (AlN), noted for its excellent thermal conductivity and exceptional electrical insulation, presents a promising alternative to traditional ceramic particles in thermal interface materials (TIMs). However, its broader adoption in practical applications is limited by performance degradation due to the vulnerability of its crystal structure to ubiquitous moisture. This study introduces a dual solution, utilizing a mechanochemical method to design a dense outer layer of Galinstan liquid metal (LM) that simultaneously enhances AlN's resistance to hydrolysis and improves its thermal performance in TIM applications. The high surface free energy of the LM layer imparts hydrophobic properties to the AlN surface and, combined with outer metal oxides, forms a dual-layer protective barrier that prevents water penetration, significantly enhancing the TIM's long-term stability in high-humidity conditions. Additionally, the LM layer at the interface improves the thixotropic properties of the TIM and enhances interfacial heat transport through the bridging effect of the LM, resulting in improved rheological mobility and thermal conductivity of the composite material. This win-win surface modification strategy opens opportunities for the practical and durable application of AlN in widespread electronic thermal management.

Improving the Bio-Tribological Properties of Ti6Al4V Alloy via Combined Treatment of Femtosecond Laser Nitriding and Texturing

This paper presents a compound laser surface modification strategy to enhance the tribological performance of biomedical titanium alloys involving femtosecond laser nitriding and femtosecond laser texturing. First, high-repetition-rate femtosecond pulses (MHz) were used to melt the surface under a nitrogen atmosphere, forming a wear-resistant TiN coating. Subsequently, the TiN layer was ablated in air with low-repetition-rate femtosecond pulses (kHz) to create squared textures. The effects of the combined nitriding and texturing treatment on bio-tribological performance was investigated. Results show that compared with the untreated samples, the single femtosecond laser nitriding process increased the surface hardness from 336 HV to 1455 HV and significantly enhanced the wear resistance of titanium, with the wear loss decreasing from 9.07 mg to 3.41 mg. However, the friction coefficient increased from 0.388 to 0.655, which was attributed to the increased hardness, roughness within the wear scars, and the formation of hard debris. After combined treatment, the friction coefficient decreased to 0.408 under the optimal texture density of 65%. The mechanisms for the improvement in friction behavior are the reduction in contact area and the trapping of hard debris.

Inhibition of bacteria adhesion and biofilm formation using a precisely structured nitric oxide-releasing coating with repeatedly renewing antimicrobial and antifouling ability

Bacterial adhesion and colonization usually causes the formation of biofilm that cannot be easily eradicated by common antibiotics and disinfectants. Surface covalent immobilization of nitric oxide (NO)-releasing polymer is an effective surface modification strategy to combat the threat from bacteria. Although surface covalent strategy avoided the leaching of toxic NO donors, the existence of hydrophobic NO donors on topsurface could inevitably accelerate the microorganism adhesion and accumulation, and the NO-releasing period of time was still very limited. In this work, we prepared an antimicrobial and antibiofilm surface via tethering a precision-structured NO-releasing copolymer brush to an organic-inorganic hybrid hard coating (> 5H pencil hardness) on one end. The precision-structured diblock copolymer brush was composed of a surface antifouling block and a subsurface antimicrobial block of NO-releasing units. A typical effect of “kill two birds with one stone” was observed, the NO releasing subsurface segment within a polymeric matrix prolongs NO release while also preventing surface fouling caused by hydrophobic NO donors on top surface. The impacts of polymer architecture on bioactivity was detailed investigated, and the block copolymer brush exhibited the optimal inhibitory effects against bacteria colonization and biofilm formation. The developed bioactive diblock copolymer brush was grafted from a hard hybrid persistent coating that embeds considerable initiation sites for surface modification. Thanks to the presence of initiator throughout the hybrid network, the initiation layer could initiate polymerization repeatedly after the polymer brushes are worn off at high pressure. Thus, the coating exhibited repeatedly renewing antimicrobial and antifouling ability after multiple abrasion cycles. This work not only developed a novel strategy for regulating NO releasing via modulating the polymer architecture, but provided a feasible route for obtaining a robust initiator layer for synthesizing polymer brush for antimicrobial and antifouling applications.

Bi-Functional Interfacial Modification enables Highly-Exposed Zn(002) Crystal Facet towards Durable Zn Metal Batteries.

Zn-ion batteries (ZIBs) have garnered growing interest in large-scale energy storage devices for the high safety, high theoretical capacity and low electrochemical potential. Nevertheless, their widespread applications are significantly impeded by dendrite formation, hydrogen evolution and corrosion reactions of Zn anodes. Herein, a bi-functional polyacrylic acid (PAA) modified-Zn anode (Zn-PAA) is designed to concurrently inhibit Zn dendrite formation and alleviate side reactions. The bi-functional PAA coating not only selectively acid-etches the active Zn crystal facets to guide the planar deposition along the highly-exposed Zn(002) crystal facet, but also facilitate uniform Zn deposition through coordination between the polymer functional groups and Zn2+. Meanwhile, the electrically-insulated PAA protective layer effectively separates Zn anodes from the electrolyte and modulates the solvation structure of Zn2+.6H2O, significantly suppressing side reactions. Consequently, the assembled Zn-PAA//Zn-PAA symmetrical cell delivers an outstanding cycling stability of 1600 h at 1 mA cm-2 and 1 mAh cm-2. The assembled KVO//Zn-PAA full cell shows exceptional cycling stability over 1500 cycles at 2.0 A g-1 with a high Coulombic efficiency approaching 100%. The facile bi-functional surface modification strategy, which enables to finely tune the crystal facet texture and ion distribution manner, opens up a groundbreaking path towards safe and durable ZIBs.

Enhanced Cancer Biomarker Detection using Fe3O4 Magnetic Nanoparticles: Synthesis, Surface Modifications and Diagnostic Applications: A Review

Fe3O4 magnetic nanoparticles exhibit significant potential for cancer detection due to their unique magnetic properties and versatility. This review examines their role in enhancing cancer biomarker detection, focusing on synthesis methods, surface modifications and diagnostic accuracy. Fe3O4 nanoparticles serve as sensitive MRI contrast agents, facilitating early cancer diagnosis and improving patient prognosis. Synthesis techniques influence their properties, morphology and dimensions, which affect performance. Surface modifications enhance targeting and reduce immunological reactions, enabling precise biomarker detection and effective drug delivery to tumours, minimizing damage to healthy tissue. Despite these advantages, challenges remain in optimizing delivery efficiency and overcoming medication resistance. Further research is required to understand the pharmacokinetics and pharmacodynamics of these nanoparticles, including their distribution, metabolism and physiological impacts. This review provides insights into the potential of Fe3O4 magnetic nanoparticles as cancer detection agents, aiming to guide future research towards developing safer and more efficient applications in medical diagnostics and treatment. HIGHLIGHTS Fe3O4 magnetic nanoparticles exhibit unique magnetic properties that are highly effective in detecting cancer biomarkers. These nanoparticles enable early cancer diagnosis by identifying biomarkers at low concentrations with high sensitivity. The review assesses various synthesis techniques for Fe3O4 magnetic nanoparticles to optimize their detection capabilities. Exploration of surface modification strategies to enhance the functionality and efficacy of Fe3O4 nanoparticles in cancer biomarker detection. Enhanced diagnostic accuracy through the application of Fe3O4 magnetic nanoparticles, promising improved outcomes in cancer detection technologies. GRAPHICAL ABSTRACT

Enhanced photocatalytic degradation activity of titanium dioxide by adsorbing aromatic amines through N-bonding

Narrowing the wide band gap of TiO2 (∼3.2 eV) to enhance its visible light efficiency is crucial for advancing photocatalytic degradation of organic pollutants in industrial wastewater. In this study, we achieved band gap reduction and slowed recombination rates by adsorbing some aromatic amines, like aniline and its electron-donating derivatives, onto TiO2. The predominantly present N-bonded amine species reduced the band gap and decelerated charge carriers’ recombination, enhancing photocatalytic degradation under visible light. In contrast, the amine with electron-withdrawing group is adsorbed as only H-bonded species, which showed no improvement in photocatalytic activity, performing similarly to pristine TiO2. This surface modification strategy offers potential for creating visible light-driven photocatalysts for effective degradation of organic pollutants in water.

Improving the electrochemical performance of lithium-rich manganese-based cathode materials by Na₂S₂O₈ surface treatment

Lithium-rich manganese-based cathode materials are well-regarded for their high specific capacity and notable voltage thresholds, making them attractive for advanced energy storage applications. However, their widespread commercialization is hindered by challenges in cycle performance, including suboptimal initial Coulombic efficiency, inadequate cycle stability, and constrained rate capability. To address these issues, this paper introduces a novel modification strategy using Na₂S₂O₈ to chemically delithiate the surface of the materials. This modification strategy dramatically enhances the initial Coulombic efficiency. The results demonstrate that the initial Coulombic efficiency of the two pre-activated samples improved to 84.6 % and 102.2 %, respectively. At the same time, the Na₂S₂O₈-treated samples exhibit a higher maximum discharge capacity at a 0.2 C rate, reaching 211.1 mAh g⁻¹ and 201.3 mAh g⁻¹, which notably surpasses the untreated sample's capacity of 188.7 mAh g⁻¹. Additionally, the treated samples exhibit improved cycling and rate performance, with capacity retention of 81.2 % and 63.5 %, respectively. After 60 cycles, these figures continue to be superior to those of the untreated material, which stands at 57.3 %. The results demonstrate that Na₂S₂O₈ treatment leads to the in situ formation of spinel phases on the material surface, thereby enhances the cycling stability and rate capability of the cathode material. Compared to traditional surface treatment methods, Na₂S₂O₈ solution treatment can induce more profound structural evolution without necessitating high-temperature calcination, thus reducing the demands on process conditions and equipment and offering greater process controllability. Moreover, this surface modification strategy paves the way for applying spinel coatings on other substrates with similar structures.

Tuning interfacial molecular asymmetry to engineer protective coatings with superior surface anchoring, antifouling and antibacterial properties

Multifunctional robust protective coatings that combine biocompatibility, antifouling and antimicrobial properties play an essential role in reducing host reactions and infection on invasive medical devices. However, developing these protective coatings generally faces a paradox: coating materials capable of achieving robust adhesion to substrates via spontaneous deposition inevitably initiate continuous biofoulant adsorption, while those employing strong hydration capability to resist biofoulant attachment have limited substrate binding ability and durability under wear. Herein, we designed a multifunctional terpolymer of poly(dopamine methyacrylamide-co-2-methacryloyloxyethyl phoasphorylcholine-co-2-(dimethylamino)-ethyl methacrylate) (P(DMA-co-MPC-co-DMAEMA)), which integrates desired yet traditionally incompatible functions (i.e., robust adhesion, antifouling, lubrication, and antimicrobial properties). Direct normal and lateral force measurements, dynamic adsorption tests, surface ion conductance mapping were applied to comprehensively investigate the nanomechanics of coating-biofloulant interactions. Catechol groups of DMA act as basal anchors for robust substrate deposition, while the highly hydrated zwitterion of MPC provides apical protection to resist biofouling and wear. Moreover, the antimicrobial property is conferred through the protonation of tertiary amine groups on DMAEMA, inhibiting infection under physiological conditions. This work provides an effective strategy for harmonizing demanded yet incompatible properties in one coating material, with significant implications for the development of multifunctional surfaces towards the advancement of invasive biomedical devices. Statement of significanceMultifunctional robust protective coatings have been widely utilized in invasive medical devices to mitigate host responses and infection. However, modified surface coatings often encounter a trade-off between robust adhesion to substrates and strong hydration capability for antifouling and antimicrobial properties. We propose a universal strategy for surface modification by dopamine-assisted co-deposition with a multifunctional terpolymer of P(DMA-co-MPC-co-DMAEMA) that simultaneously achieves robust adhesion, antifouling, and antimicrobial properties. Through elucidating the nanomechanics with fundamentally understanding the interactions between the coating and biomacromolecules, we highlight the role of DMA for substrate adhesion, MPC for biofouling resistance, and DMAEMA for antimicrobial activity. This approach presents a promising strategy for constructing multifunctional coatings on minimally invasive medical devices by tuning interfacial molecular asymmetricity to reconcile incompatible properties within one coating.

Stabilization of single crystal LiNi0.90Mn0.05Co0.05O2 via ZrO2 dual-functional coating enables superior performance for solid-state lithium battery

Chlorine-rich argyrodites with ultrafast Li-ion conductivities exhibits great potential as solid electrolytes for all-solid-state lithium batteries. However, the poor interfacial stability and slow ion dynamics between Li5.5PS4.5Cl1.5 (Cl1.5) and high nickel layered cathode hinder the achievement of superior battery performances. Here, the prepared ZrO2 coating film was found to perform two functions: enhancing the bulk and interfacial stability of single crystal LiNi0.90Mn0.05Co0.05O2 (NCM911) towards sulfide, and facilitating Li-ion transport rates across the interface. A Li2ZrO3 phase with fast Li-ion diffusion rate generates during cycling and further improve the layered-structure integrity of NCM911 and interfacial stability toward the Cl1.5 electrolyte, which are due to the reduction of lattice oxygen release from NCM911 and the isolation of direct contact between the two materials. As a result, these effects enable superior electrochemical performances for the ZrO2-coated NCM911 than the bare sample in Cl1.5-based all-solid-state lithium batteries at varying C-rates and different operating temperatures. It delivers high initial discharge capacities of 156.6 mAh g−1 at 2C and retains 86.0 % of its capacity after 1000 cycles at room temperature, and displays an initial discharge capacity of 172.6 mAh g−1 at 0.5C under 60 °C and 142.4 mAh g−1 at 0.1C under –20 °C, respectively. This dual-functional surface modification strategy provides guidelines to stabilize high-nickel cathode in sulfide-based all-solid-state lithium batteries.

Swelling-assisted surface grafting strategy for multichannel antifouling membranes: Reconstruction of surface pore structure and applications in microalgae harvesting and blood purification

Membrane fouling remains a major challenge in membrane separation. The modification of hydrophilic membrane surfaces can mitigate irreversible fouling deposition, thereby improving antifouling properties. Effective surface modification strategies are essential techniques for developing highly efficient antifouling membranes. In this work, a swelling-assisted surface grafting strategy was proposed for multichannel antifouling membranes, where various lengths of polyvinylpyrrolidone (PVP) brushes were grafted on the surface of polysulfone membrane using reversible addition-fragmentation chain transfer polymerization. The successful grafting of PVP polymer brushes was confirmed using Fourier transform infrared spectrometer and X-ray Photoelectron Spectroscopy. Changes in membrane morphology and pore structure were observed via scanning electron microscope and atomic force microscope. During the grafting process, the amphiphilic macromolecules formed through grafting were selectively swelled by graft solvent, leading to the formation of mesopores in both the surface layer and sublayer of the membrane, which formed additional water transport channels. The introduction of hydrophilic polymer brushes and the change of pore structure significantly boosted the hydrophilicity and permeability of the membranes. As a result, the water contact angle decreased from 85° to 42°, accompanied by an approximate 3.24-fold increase in pure water flux (PWF). Due to superior hydrophilicity, modified membranes demonstrated exemplary performance in microalgae harvesting, boasting a microalgae retention rate nearing 100 % and low fouling resistance (2.12 × 1012 m−1). In algal filtration experiments, a confocal laser scanning microscope was employed to assess the activity of filtered algae on the membrane surface. The prepared membranes effectively maintained the bioactivity of algae while also achieving a high flux recovery rate (90.7 %) following filtration and cleaning. Furthermore, in blood cell compatibility tests, the modified membranes exhibited resistance to blood cell adhesion and sustained a low hemolysis rate (0.06 %). Overall, this strategy offers unique insights into the fabrication of antifouling surfaces and shows considerable promise for large-scale applications in microalgae harvesting and blood purification.

Interface engineering of AgI/(P, K)-g-C3N4 novel S-scheme heterostructures as a highly efficient photocatalyst for RhB degradation

In this study, we developed an in-situ deposition method to load small-sized AgI nanoparticles as an oxidative photocatalyst (OP) onto phosphorus (P) and potassium (K) co-doped two-dimensional porous g-C3N4 (PK-CN-N) as a reductive photocatalyst (RP), forming an S-scheme heterojunction photocatalyst AgI/PK-CN-N. PK-CN-N achieved morphology control and element doping, leading to surface functionalization and heterostructure formation for the AgI/PK-CN-N photocatalyst. Notably, the 50AgI/PK-CN-N composite demonstrated an approximately 95 % removal efficiency for RhB within 30 minutes, 17.6 times higher than pure g-C3N4, surpassing most reported g-C3N4-based photocatalysts. The enhanced photocatalytic efficiency is attributed to the surface modification strategy and heterostructure formation of g-C3N4, which broadens the visible light response range, increases the number of active sites, improves the separation of photogenerated electron-hole pairs, and enhances REDOX capabilities. The band structure of the composite was elucidated through Mott-Schottky analysis and UV–vis DRS. The formation of the AgI/PK-CN-N S-scheme heterojunction and its charge transfer mechanism was confirmed through XPS, band structure analysis, KPFM, and EPR spectroscopy. Experimental data confirmed the presence of a strong and effective interface electric field between the two semiconductors, leading to band bending and accelerated charge separation. Additionally, the introduction of small-sized AgI semiconductors enhanced the exposure of the coupling interface, further improving catalytic performance. The reusability and lifespan of the catalyst were also analyzed, showing that after four cycles, the photocatalytic activity remained above 92 %.