Potassium-ion batteries are a promising alternative to lithium-ion batteries. However, it is challenging to achieve fast charging/discharging and long cycle life with the current electrode materials ...because of the sluggish potassiation kinetics. Here we report a soft carbon anode, namely highly nitrogen-doped carbon nanofibers, with superior rate capability and cyclability. The anode delivers reversible capacities of 248 mAh g
at 25 mA g
and 101 mAh g
at 20 A g
, and retains 146 mAh g
at 2 A g
after 4000 cycles. Surface-dominated K-storage is verified by quantitative kinetics analysis and theoretical investigation. A full cell coupling the anode and Prussian blue cathode delivers a reversible capacity of 195 mAh g
at 0.2 A g
. Considering the cost-effectiveness and material sustainability, our work may shed some light on searching for K-storage materials with high performance.
Carbon‐based nanomaterials have significantly pushed the boundary of electrochemical performance of lithium‐based batteries (LBs) thanks to their excellent conductivity, high specific surface area, ...controllable morphology, and intrinsic stability. Complementary to these inherent properties, various synthetic techniques have been adopted to prepare carbon‐based nanomaterials with diverse structures and different dimensionalities including 1D nanotubes and nanorods, 2D nanosheets and films, and 3D hierarchical architectures, which have been extensively applied as high‐performance electrode materials for energy storage and conversion. The present review aims to outline the structural design and composition engineering of carbon‐based nanomaterials as high‐performance electrodes of LBs including lithium‐ion batteries, lithium–sulfur batteries, and lithium–oxygen batteries. This review mainly focuses on the boosting of electrochemical performance of LBs by rational dimensional design and porous tailoring of advanced carbon‐based nanomaterials. Particular attention is also paid to integrating active materials into the carbon‐based nanomaterials, and the structure–performance relationship is also systematically discussed. The developmental trends and critical challenges in related fields are summarized, which may inspire more ideas for the design of advanced carbon‐based nanostructures with superior properties.
Carbon‐based nanomaterials represent cutting‐edge materials in energy storage and conversion fields due to their superior properties. This review summarizes the dimensional design and composition engineering of carbon‐based materials for boosting lithium storage capability, and further discusses their structure–performance relationship. The development trends and critical challenges are also given for the design of advanced carbon‐based electrode materials.
Nanostructured‐alloy‐type anodes have received great interest for high‐performance lithium‐ion batteries (LIBs). However, these anodes experience huge volume fluctuations during repeated ...lithiation/delithiation and are easily pulverized and subsequently form aggregates. Herein, an efficient method to stabilize alloy‐type anodes by creating defects on the surface of the metal oxide support is proposed. As a demonstration, PPy‐encapsulated SnS2 nanosheets supported on defect‐rich TiO2 nanotubes were produced and investigated as an anode material for LIBs. Both experimental results and theoretical calculations demonstrate that defect‐rich TiO2 provides more chemical adhesions to SnS2 and discharge products, compared to defect‐poor TiO2, and then effectively stabilizes the electrode structure. As a result, the composite exhibits an unprecedented cycle stability. This work paves the way to designing durable and active nanostructured‐alloy‐type anodes on oxide supports.
PPy‐encapsulated SnS2 nanosheets strongly anchored onto a hydrogen‐treated TiO2 (H–TiO2) support have been successfully prepared as an anode for LIBs. As demonstrated by first principles, theoretical calculations, and experimental results, the superior binding between SnS2 and the H–TiO2 support via abundant Ti–S bonding, which is reinforced by the oxygen vacancy, contributes to the unprecedented cycle stability.
Potassium‐ion batteries (KIBs) in organic electrolytes hold great promise as an electrochemical energy storage technology owing to the abundance of potassium, close redox potential to lithium, and ...similar electrochemistry with lithium system. Although carbon materials have been studied as KIB anodes, investigations on KIB cathodes have been scarcely reported. A comprehensive study on potassium Prussian blue K0.220FeFe(CN)60.805⋅4.01H2O nanoparticles as a potential cathode material is for the first time reported. The cathode exhibits a high discharge voltage of 3.1–3.4 V, a high reversible capacity of 73.2 mAh g−1, and great cyclability at both low and high rates with a very small capacity decay rate of ≈0.09% per cycle. Electrochemical reaction mechanism analysis identifies the carbon‐coordinated FeIII/FeII couple as redox‐active site and proves structural stability of the cathode during charge/discharge. Furthermore, for the first time, a KIB full‐cell is presented by coupling the nanoparticles with commercial carbon materials. The full‐cell delivers a capacity of 68.5 mAh g−1 at 100 mA g−1 and retains 93.4% of the capacity after 50 cycles. Considering the low cost and material sustainability as well as the great electrochemical performances, this work may pave the way toward more studies on KIB cathodes and trigger future attention on rechargeable KIBs.
Potassium Prussian blue nanoparticles are reported as a potential cathode material for potassium‐ion batteries. The cathode exhibits high reversible capacity, excellent cyclability, and great rate capability. Electrochemical mechanism analysis reveals the active‐redox site and proves the structural stability during charge/discharge. Pairing with commercially available carbon materials, a potassium‐ion battery full cell is demonstrated for the first time.
Efficient and stable nonprecious metal electrocatalysts for oxygen reduction are of great significance in some important electrochemical energy storage and conversion systems. As a unique class of ...porous hybrid materials, metal–organic frameworks (MOFs) and their composites are recently considered as promising precursors to derive advanced functional materials with controlled structures and compositions. Here, an “MOF‐in‐MOF hybrid” confined pyrolysis strategy is developed for the synthesis of porous Fe–Co alloy/N‐doped carbon cages. A unique “MOF‐in‐MOF hybrid” architecture constructed from a Zn‐based MOF core and a Co‐based MOF hybrid shell encapsulated with FeOOH nanorods is first prepared, followed by a pyrolysis process to obtain a cage‐shaped hybrid material consisting of Fe–Co alloy nanocrystallites evenly distributed inside a porous N‐doped carbon microshell. Of note, this strategy can be extended to synthesize many other multifunctional “nanosubstrate‐in‐MOF hybrid” core–shelled structures. Benefiting from the structural and compositional advantages, the as‐derived hybrid cages exhibit superior electrocatalytic performance for the oxygen reduction reaction in alkaline solution. The present approach may provide some insight in design and synthesis of complex MOF hybrid structures and their derived functional materials for energy storage and conversion applications.
A metal–organic frameworks (MOF)‐in‐MOF hybrid confined pyrolysis strategy is developed to synthesize porous Fe–Co alloy/N‐doped carbon cages. With the structural and compositional advantages, these unique hybrid materials exhibit superior electrocatalytic performance for oxygen reduction reactions in alkaline electrolytes.
Covalent organic frameworks (COF) or metal–organic frameworks have attracted significant attention for various applications due to their intriguing tunable micro/mesopores and ...composition/functionality control. Herein, a coordination‐induced interlinked hybrid of imine‐based covalent organic frameworks and Mn‐based metal–organic frameworks (COF/Mn‐MOF) based on the MnN bond is reported. The effective molecular‐level coordination‐induced compositing of COF and MOF endows the hybrid with unique flower‐like microsphere morphology and superior lithium‐storage performances that originate from activated Mn centers and the aromatic benzene ring. In addition, hollow or core–shell MnS trapped in N and S codoped carbon (MnS@NS‐C‐g and MnS@NS‐C‐l) are also derived from the COF/Mn‐MOF hybrid and they exhibit good lithium‐storage properties. The design strategy of COF–MOF hybrid can shed light on the promising hybridization on porous organic framework composites with molecular‐level structural adjustment, nano/microsized morphology design, and property optimization.
Based on the coordinated interaction between CN groups from covalent organic frameworks and Mn ions of metal–organic frameworks, a coordination‐induced interlinked hybrid of COF/Mn‐MOF is designed with flower‐like morphology. A synergistic effect relative to new active sites for lithium storage endows it with superior application performance. Hollow or core–shell microspheres of MnS@N/S codoped carbons can also be derived with superior electrochemical properties.
Size, shape, and protein corona play a key role in cellular uptake and removal mechanisms of gold nanoparticles (Au NPs). The 15 nm nanoparticles (NP1), the 45 nm nanoparticles (NP2), and the ...rod‐shaped nanoparticles (NR) enter into cells via a receptor‐mediated endocytosis (RME) pathway. The star‐shaped nanoparticles (NS) adopt not only clathrin‐mediated, but also caveolin‐mediated endocytosis pathways. However, the 80 nm nanoparitcles (NP3) mainly enter into the cells by macropinocytosis pathway due to the big size. Furthermore, the results indicate that the presence of protein corona can change the uptake mechanisms of Au NPs. The endocytosis pathway of NP1, NP2, and NS changes from RME to macropinocytosis pathway and NR changes from RME to clathrin and caveolin‐independent pathway under the non‐fetal bovine serun (FBS)‐coated condition. Both FBS‐coated and non‐FBS‐coated of five types of Au NPs are released out through the lysosomal exocytosis pathway. The size, shape, and protein corona have an effect on the exocytosis ratio and amount, but do not change the exocytosis mechanism. The systematic study of the endocytosis and exocytosis mechanism of Au NPs with different sizes and shapes will benefit the toxicology evaluation and nanomedicine application of Au NPs.
Size, shape, and protein corona play the key role in cellular uptake and removal mechanisms of gold nanoparticles (Au NPs). The uptake mechanisms of five types of Au NPs are different. Size, shape, and protein corona decrease the uptake amount and affect the endocytosis mechanism. However, all of them are released through the lysosomal exocytosis pathway.
Highly blue luminescent carbon nanoparticles with photo-luminescence quantum yields of 31.6%-40.6% were prepared by a one-step pyrolytic route from ethylenediamine-tetraacetic acid salts and a unique ...emission that is strongly dependent on pH, solvent, spin, and excitation wavelength was observed.
► Heavy metals were found coexisting with antibiotics in manures and manure-amended agricultural soils. ► The relative abundance of sulfonamide and tetracycline ARGs were high in manures and soils. ► ...Positive but weak correlations were found between ARGs and their corresponding antibiotics. ► Significant positive correlations were found between some ARGs and typical heavy metals such as Cu, Zn, and Hg. ► Metals able to induce the SOS response may accelerate the dissemination of antibiotic resistance.
Eight antibiotic resistance genes (ARGs), 7 heavy metals, and 6 antibiotics were quantified in manures and soils collected from multiple feedlots in Shanghai. The samples were analyzed to determine if ARG abundances were associated with heavy metal concentration and independent of antibiotics. The results revealed the presence of chloramphenicol, sulfonamides and tetracyclines at concentration ranges of 3.27–17.85, 5.85–33.37 and 4.54–24.66mgkg−1, respectively. Typical heavy metals, such as Cu, Zn, and As, were detected at concentration ranges of 32.3–730.1, 75.9–4333.8, and 2.6–617.2mgkg−1. All ARGs tested were detected in the collected samples except tetB(P), which was absent in animal manures. Overall, sulfonamide ARGs were more abundant than tetracycline ARGs. Except for sulII, only a weak positive correlation was found between ARGs and their corresponding antibiotics. On the contrary, significant positive correlations (p<0.05) were found between some ARGs and typical heavy metals. For example, sulA and sulIII were strongly correlated with levels of Cu, Zn and Hg. The data demonstrated that the presence of ARGs was relatively independent of their respective antibiotic inducer. In addition to antibiotics, toxic heavy metals, such as Hg, Cu, and Zn, exerted a strong selection pressure and acted as complementary factors for ARG abundance.
Graphitic carbon nitride (g-C3N4) has drawn great attention recently because of its visible light response, suitable energy band gap, good redox ability, and metal-free nature. g-C3N4 can absorb ...visible light directly, therefore has better photocatalytic ability under solar irradiation and is more energy-efficient than TiO2. However, pure g-C3N4 still has the drawbacks of insufficient light absorption, small surface area and fast recombination of photogenerated electron and hole pairs. This review summarizes the recent progress in the development of g-C3N4 nanocomposites to photodegrade organic contaminants in water. Element doping especially by potassium has been reported to be an efficient method to promote the degradation efficacy. In addition, compound doping improves photodegradation performance of g-C3N4, especially Ag3PO4-g-C3N4 which can completely degrade 10mgL−1 of methyl orange under visible light irradiation in 5min, with the rate constant (k) as high as 0.236min−1. Moreover, co-doping enhances the photodegradation rate of multiple contaminants while immobilization significantly improves catalyst stability. Most of g-C3N4 composites possess high reusability enabling their practical applications in wastewater treatment. Furthermore, environmental conditions such as solution pH, reaction temperature, dissolved oxygen, and dissolved organic matter all have important effects on the photocatalytic ability of g-C3N4 photocatalyst. Future work should focus on the synthesis of innovative g-C3N4 nanocomposites for the efficient removal of organic contaminants in water and wastewater.
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•g-C3N4 catalyst performs better than TiO2 in visible photocatalysis of dyes.•Photodegradation by g-C3N4 is particularly enhanced by K-doping.•Compound doping especially Ag3PO4-g-C3N4 improves photodegradation effect.•Co-doping can degrade multiple contaminants with high degradation rate constant.•Synthesized g-C3N4 nanocomposites have shown good reusability.
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