Search

The low cycling efficiency and uncontrolled dendrite growth resulting from an unstable and heterogeneous lithium-electrolyte interface have largely hindered the practical application of lithium metal batteries. In this study, a robust all-organic interfacial protective layer has been developed to achieve a highly efficient and dendrite-free lithium metal anode by the rational integration of porous polymer-based molecular brushes (poly(oligo(ethylene glycol) methyl ether methacrylate)-grafted, hypercrosslinked poly(4-chloromethylstyrene) nanospheres, denoted as xPCMS-g-PEGMA) with single-ion-conductive lithiated Nafion. The porous xPCMS inner cores with rigid hypercrosslinked skeletons substantially increase mechanical robustness and provide adequate channels for rapid ionic conduction, while the flexible PEGMA and lithiated Nafion polymers enable the formation of a structurally stable artificial protective layer with uniform Li

Due to the unique physical and chemical merits including excellent electrical conductivity, superior chemical stability, and tunable carbon framework, two-dimensional (2D) porous carbon nanosheets have drawn increasing research interest and demonstrated promising potentials in various applications. However, regulating the nanostructure of 2D porous carbon nanosheets by facile and efficient strategies remains a great challenge. Herein, we develop a new strategy to construct Fe, N-codoped hierarchical porous carbon nanosheets (Fe-N-HPCNS) by using 2D Fe-Zn layered double hydroxides (Fe-Zn-LDH) as multifunctional templates. Fe-Zn-LDH could functionalize not only as 2D structure directing agents but also as ternary hierarchical porogens for micro-, meso- and macropores and in situ Fe dopants. This multifunctional templating strategy toward 2D porous carbon nanosheets can improve the utilization of templates and shows great advantages against conventional procedures that additional porogens and/or dopants are often needed.

Lithium metal anode has attracted wide research interests because of its very high theoretical capacity and low potential. However, severe safety issues arising from lithium dendrite growth have gripped the throat of the practical application of lithium metal batteries. Herein, a novel superstructured single-ion conducting polymer brush (CNF-g-PSSLi) is proposed as artificial solid electrolyte interphase (SEI) film to inhibit the lithium dendrite growth. The as-obtained CNF-g-PSSLi integrates merits of robust CNF backbone nanonetwork, brush-improved interfacial compatibility, -SO3− group-guided rapid transportation of lithium ions, and -SO3− group-induced electrostatic repulsion against initially formed lithium dendrites. As a result, CNF-g-PSSLi film exhibits good mechanical properties (elasticity modulus = 5.3 GPa) against dendrite growth upon cell cycling, comfortable interfacial contact, and fast ionic transport. Symmetric Li|Li cells with CNF-g-PSSLi as artificial SEI show outstanding plating/stripping stabilities at ultrahigh current densities (20 mA cm−2). In addition, Li|LiFePO4 full cell with Li@CNF-g-PSSLi anode exhibits a long lifespan (300 cycles) with a tiny capacity decay of 0.08% per cycle at a high current density of 5 C. This work could provide an efficient attempt to develop superior artificial SEI films by well-orchestrated macromolecular engineering.

Anti-PD(L)1 immunotherapy recently arises as an effective treatment against triple-negative breast cancer (TNBC) but is only applicable to a small portion of TNBC patients due to the low PD-L1 expression and the immunosuppressive tumor microenvironment (TME). To address these challenges, a multifunctional "drug-like" copolymer that possesses the auto-changeable upper critical solution temperature and the capacity of scavenging reduced nicotinamide adenine dinucleotide phosphate (NADPH) inside tumor cells is synthesized and employed to develop a hypoxia-targeted and BMS202 (small molecule antagonist of PD-1/PD-L1 interactions)-loaded nanomedicine (BMS202@HZP NPs), combining the anti-PD-L1 therapy and the low-dose radiotherapy (LDRT) against TNBC. In addition to the controlled release of BMS202 in the hypoxic TNBC, BMS202@HZP NPs benefit the LDRT by upregulating the pentose phosphate pathway (PPP, the primary cellular source for NADPH) of TME whereas scavenging the NADPH inside tumor cells. As a result, the BMS202@HZP NPs-mediated LDRT upregulate the PD-L1 expression of tumor to promote anti-PD-L1 therapy response while reprogramming the immunometabolism of TME to alleviate its immunosuppression. This innovative nanomedicine-mediated radio-immunometabolism regulation provides a promising strategy to reinforce the anti-PD-L1 therapy against TNBC.

Cobalt disulfide (CoS2 ) has been explored as attractive electrocatalyst for oxygen evolution reaction (OER). However, bulk CoS2 sheets have limited catalytic activity due to low exposure of active sites. Herein, through an in-situ vulcanization approach, CoS2 nanoparticles are embedded into bipyridine-containing covalent organic polymer (BP-COP). The as-prepared nanocomposite CoS2 @BP-COP exhibits high catalytic activity toward OER with an ultra-low overpotential of 270 mV (vs. RHE) at a current density of 10 mA cm-2 , a small Tafel slope of 36 mV dec-1 , and an excellent durability for 24 h without decay. The surface of CoS2 is partially converted into CoOOH to form CoS2 /CoOOH as active sites under OER conditions. CoS2 @BP-COP displays superior OER catalytic activity to CoS2 nanosheets and commercially available RuO2 under the same conditions. The outstanding OER performance activity of CoS2 @BP-COP could be attributed to the uniform and small particle sizes of CoS2 /CoOOH distributed in BP-COP.

Peri-implant infection is one of the biggest threats to the success of dental implant. Existing coatings on titanium surfaces exhibit rapid decrease in antibacterial efficacy, which is difficult to promisingly prevent peri-implant infection. Herein, we report an N-halamine polymeric coating on titanium surface that simultaneously has long-lasting renewable antibacterial efficacy with good stability and biocompatibility. Our coating is powerfully biocidal against both main pathogenic bacteria of peri-implant infection and complex bacteria from peri-implantitis patients. More importantly, its antibacterial efficacy can persist for a long term (e.g., 12~16 weeks) in vitro, in animal model, and even in human oral cavity, which generally covers the whole formation process of osseointegrated interface. Furthermore, after consumption, it can regain its antibacterial ability by facile rechlorination, highlighting a valuable concept of renewable antibacterial coating in dental implant. These findings indicate an appealing application prospect for prevention and treatment of peri-implant infection., Infection is a major problem for dental implants with current antibacterial coatings losing efficacy quickly. Here, the authors report on the N-halamine polymeric coating of titanium implants to create a long-lasting renewable antibacterial layer and demonstrate application in vivo.

Porous polymers have attracted tremendous interest in lithium–sulfur batteries due to the combination of good physical confinement and chemical immobilization to suppress the polysulfide shuttle. C...

A generalized and facile strategy toward 2D hybrid porous carbons (2DHPCs) with various highly active functional species (e.g. Co, B, and P) is developed via 2D molecular brushes as biomimetic building blocks. The resulting 2DHPCs present superior electrochemical energy conversion and storage properties.

Two-dimensional (2D) porous carbon materials have attracted great attention for various applications in energy conversion/storage, catalysis, and adsorption because of their unique physicochemical ...

Yolk-shell nanostructures have recently attracted tremendous research interests in various areas because of their unique structural merits. Currently, there is an urgent need for developing porous shells with multifunctional features to enhance their performance in various applications. Herein, advanced yolk-shell nanospheres have been facilely prepared by encapsulating silver nanoparticles with porous Janus polymer shells that consist of a hypercrosslinked polystyrene (xPS) outer layer and a tethered poly(acrylic acid) (PAA) brush lining. The xPS outer layer possesses well-developed porosity as mass diffusion pathways. More importantly, the tethered PAA brushes with customized carboxyl groups exhibit great affinity toward specific species (e.g., cationic dyes), leading to their enrichment from the bulk solution into the interior cavity. The unusual combination of highly porous outer layers with customizable inbuilt polymer linings in the porous Janus shells endows them with great promise for synergistically catalytic degradation of cationic dyes.

Porous organic polymers (POPs) have emerged as a new class of multifunctional porous materials and received tremendous research attention from both academia and industry. Most POPs are constructed from versatile organic small molecules with diverse linkages through strong covalent bonds. Owing to their high surface area and porosity, low density, high stability, tunable pores and skeletons, and ease of functionalization, POPs have been extensively studied for gas storage and separation, heterogeneous catalysis, biomedicine, sensing, optoelectronics, energy storage and conversion

Carbon‐based nanomaterials have been regarded as promising non‐noble metal catalysts for renewable energy conversion system (e.g., fuel cells and metal–air batteries). In general, graphitic skeleton and porous structure are both critical for the performances of carbon‐based catalysts. However, the pursuit of high surface area while maintaining high graphitization degree remains an arduous challenge because of the trade‐off relationship between these two key characteristics. Herein, a simple yet efficient approach is demonstrated to fabricate a class of 2D N‐doped graphitized porous carbon nanosheets (GPCNSs) featuring both high crystallinity and high specific surface area by utilizing amine aromatic organoalkoxysilane as an all‐in‐one precursor and FeCl3·6H2O as an active salt template. The highly porous structure of the as‐obtained GPCNSs is mainly attributed to the alkoxysilane‐derived SiO x nanodomains that function as micro/mesopore templates; meanwhile, the highly crystalline graphitic skeleton is synergistically contributed by the aromatic nucleus of the precursor and FeCl3·6H2O. The unusual integration of graphitic skeleton with porous structure endows GPCNSs with superior catalytic activity and long‐term stability when used as electrocatalysts for oxygen reduction reaction and Zn–air batteries. These findings will shed new light on the facile fabrication of highly porous carbon materials with desired graphitic structure for numerous applications., 2D N‐doped graphitized porous carbon nanosheets (GPCNSs) featuring both high crystallinity and high specific surface area are prepared by molecular engineering. The unusual integration of graphitic skeleton with porous structure endows GPCNSs with superior catalytic activity and long‐term stability when used as electrocatalysts for oxygen reduction reaction and Zn–air batteries.

Implantable meshes used in tension-free repair operations facilitate treatment of internal soft-tissue defects. However, clinical meshes fail to achieve anti-deformation, anti-adhesion, and pro-healing properties simultaneously, leading to undesirable surgery outcomes. Herein, inspired by the peritoneum, a novel biocompatible Janus porous poly(vinyl alcohol) hydrogel (JPVA hydrogel) is developed to achieve efficient repair of internal soft-tissue defects by a facile yet efficient strategy based on top-down solvent exchange. The densely porous and smooth bottom-surface of JPVA hydrogel minimizes adhesion of fibroblasts and does not trigger any visceral adhesion, and its loose extracellular-matrix-like porous and rough top-surface can significantly improve fibroblast adhesion and tissue growth, leading to superior abdominal wall defect treatment to commercially available PP and PCO meshes. With unique anti-swelling property (maximum swelling ratio: 6.4%), JPVA hydrogel has long-lasting anti-deformation performance and maintains high mechanical strength after immersion in phosphate-buffered saline (PBS) for 14 days, enabling tolerance to the maximum abdominal pressure in an internal wet environment. By integrating visceral anti-adhesion and defect pro-healing with anti-deformation, the JPVA hydrogel patch shows great prospects for efficient internal soft-tissue defect repair.

One-pot template-free fabrication of hollow hybrid carbon spheres with encapsulated functional particles is highly appealing yet remains a challenge. Recently in Matter, Kaskel and co-workers reported a domino-driven strategy for the versatile synthesis of hollow carbon spheres coaxially encapsulating diverse ultrafine metal nitrides/oxides.

Nonstoichiometric silica suboxides (SiOx) have been regularly investigated as hopeful anode materials for the substitutions of silicon. However, the inherently poor conductivity of SiOx limits its ...

A novel strategy is developed to produce an FeS-FeNC-decorated hierarchical porous N,S-co-doped carbon (FeS-FeNC@NSC) electrocatalyst via introducing volatile FeCl3 into a porphyrin polymer framework followed by carbonization. The synergistic effect between the FeS nanoparticles and FeNC active sites in FeS-FeNC@NSC is beneficial for enhancing the ORR activity.

Advanced antimicrobial agents that treat infectious diseases are greatly needed. Various silver-based nanomaterials have been developed and are considered potential candidates for many commercial products, but they lack durability and adequate antibacterial activity. A new class of nanohybrids of silver nanoparticles (AgNPs) grown in-situ on graphene oxide (GO) using a silver ion salt was synthesized by a simple ultrasonic mixing method. The structure and composition of the nanohybrids were investigated by SEM, TEM, FTIR, TGA, XRD and XPS. Results indicated that GO acts not only as a negatively charged macromolecule for capturing Ag+ ions, but also a reducing agent to reduce the Ag+ ions to AgNPs. The heterogeneous structure leads to abundant well-dispersed AgNPs and Ag+ ions on the GO support. The as-prepared nanohybrids make full use of the advantages of both AgNPs and GO-Ag+ salts, leading to improved and long-term antibacterial activity against both S.aureus and E. coli.

A kind of three-dimensionally nanostructured carbon materials (3DNCMs) with tube-in-tube structure was fabricated based on a novel structural design and precise control of ternary bottlebrushes by surface-initiated atom transfer radical polymerization (SI-ATRP). The 3D interconnected network of 3DNCMs consists of the hybrid carbon framework with unique tube-in-tube structure rooting from the ternary bottlebrushes and the microporous carbon shell generated from the carbonization of hypercrosslinked polystyrene (PS). The nanostructure of 3DNCMs can be changed precisely by controlling the ternary bottlebrush structures. The tube-in-tube structure provides 3DNCMs an abundant of microspores within outer amorphous carbon tube and a lot of mesopores from the removal of coated silica, which favor for the hosting of sulfur element. Moreover, carbon nanotubes, the core of the tube-in-tube structure, afford the 3DCNMs with excellent electrical conductivity. In view of the prominent advantages of the tube-in-tube structure, the sulfur cathode based on 3DNCMs hosts shows a remarkable rate capability and reversible discharge capacity of 691 mAh g−1 after 200 cycles at a 2 C current density. We hope this concept of novel design and construction of well-defined nanostructure will pave the way toward high-performance nanoporous carbon materials for energy storage and other practical applications.

Nowadays, it has been more and more important to ingeniously design sheet-like structures since the performance of many modern materials fundamentally depends upon the exploitation of these structures. In this work, we have successfully developed a facile and effective strategy for fabricating a class of 2D porous carbon nanosheets that simultaneously exhibit high surface areas and uniform distribution of metal chalcogenides for superior oxygen evolution reaction. The synthesis of these 2D carbon nanosheets involves the in-situ metal ion adsorption and exchange by the sulfonate radicals of polymer sheets followed by carbonization to form a series of metal chalcogenides loaded porous carbon nanosheets (PCNs/MxSy). The abundant mesopores (e.g., 3–7 nm, 524 m2 g−1) that derived from the spontaneous stacking of flexible GO precursor are advantageous to the exposure of heteroatom sites. The uniform catalytic sites (33.8 nm) formed in-situ effectively avoid the agglomeration of functional components, which are conducive to make full use of catalytic sites and consequently shows excellent OER performance. We hope that our novel strategy can open a new door for the application and innovation of fabricating 2D porous carbon nanosheets in a wide range of areas including energy storage, adsorption, catalysis, separation and so on.

Atom transfer radical polymerization was utilized to prepare well-defined cylindrical molecular bottlebrushes which were employed as building blocks and transformed into porous nanonetwork-structured carbons (PNSCs) via hypercross-linking chemistry and shape-regulated carbonization. The as-prepared PNSCs exhibited a unique nanomorphology-tunable characteristic by simply varying carbonization conditions. Because of their three-dimensional network nanomorphologies with well-developed hierarchical porous structures and conductive carbon framework, the PNSCs demonstrated excellent electrochemical performance in lithium-sulfur batteries.

Low removal efficiency, long treatment time, and high energy consumption hinder advanced and eco-friendly use of traditional adsorbents and separation membranes. Here, a class of amphiphilically modified 2D porous polymeric nanosandwich is designed and is subsequently assembled into adsorptive membranes. The 2D nanosandwich is gifted with high porosity and excellent pore accessibility, demonstrating rapid adsorption kinetics. The as-assembled membrane integrates unimpeded interlayer channels and well-developed, amphiphilic, and highly accessible intralayer nanopores, leading to ultrafast water permeation (1.2 × 10

Cobalt disulfide (CoS

Controlling the interfacial effect is facing challenges because of the weak interactions between the inorganic and the organic materials. We found that the silane coupling agents with -NH2 groups (e.g., KH550) play a key role as a molecular bridge that links an inorganic silica template with an organic precursor (i.e., pyrrole) in the process of constructing a spherical silica core-polypyrrole shell structure. The molecular bridge is also suitable for inorganic core templates with cube or rod shapes for the construction of different core-shell structures. These template core-polymeric shell structures can be transformed into well-defined hollow carbons after carbonization and template removal. The outer diameter, hollow-core size, and carbon shell thickness of hollow carbon materials (e.g., hollow carbon spheres) could be facilely controlled by changing the template size or the pyrrole amount. We believe that our work will provide a guideline for the preparation of well-orchestrated carbon-based composites and their templated hollow carbons.

Polymeric membranes are considered as promising materials to realize safe and long-life lithium metal batteries (LMBs). However, they are usually based on soft 1D linear polymers and thus cannot effectively inhibit piercing of lithium dendrites at high current density. Herein, single lithium-ion conducting molecular brushes (GO-g-PSSLi) are successfully designed and fabricated with a new 2D "soft-hard-soft" hierarchical structure by grafting hairy lithium polystyrenesulfonate (PSSLi) chains on both sides of graphene oxide (GO) sheets. The ultrathin GO-g-PSSLi membrane is further constructed by evaporation-induced layer-by-layer self-assembly of GO-g-PSSLi molecular brushes. Unlike conventional soft 1D linear polymeric structure, the rigid 2D extended aromatic structure of intralayer GO backbones can bear the shield effect of preventing the dendrites possibly generated at high current density from piercing. More importantly, such a shield effect can be significantly strengthened by layer-by-layer stacking of 2D molecular brushes. On the other hand, the 3D interconnected interlayer channels and the soft single lithium-ion conducting PSSLi side-chains on the surface of channels provide rapid lithium-ion transportation pathways and homogenize lithium-ion flux. As a result, LMBs with GO-g-PSSLi membrane possess long-term reversible lithium plating/striping (6 months) at high current density.

Lithium metal is the most promising candidate anode material for high energy density batteries, but its high activity and severe dendrite growth lead to safety concerns and limit its practical use. Constructing a protective layer (PL) on the lithium surface to avoid the side reactions and stabilize the electrode-electrolyte interface is an effective approach to solve these problems. In this review, the recent progress on PLs is summarized, and their desired properties and design principles are discussed from the aspects of materials selection and the corresponding fabrication methods. Advanced PLs with different properties are then highlighted, including a self-adjusting feature to increase structural integrity, the synergistic effect of organic and inorganic hybrids to improve mechanical properties and ionic conductivity, the use of embedded groups and ion diffusion channels to regulate ion distribution and flux, and a protective barrier to suppress corrosion from humid air or water. Finally, the remaining challenges and the possible solutions for PL design in future studies are proposed.

3D porous carbon networks with highly dispersed SiOx have been successfully prepared by molecular-scale engineering with 1D molecular-brush precursors. Benefiting from the high-porosity interconnected structure and the lithiophilic SiOx nanodomains, the as-obtained composites show great advantages as 3D hosts to achieve stable Li plating/stripping.