Opportunities and challenges for plastic depolymerization by biomimetic catalysis.

Plastic waste has imposed significant burdens on the environment. Chemical recycling allows for repeated regeneration of plastics without deterioration in quality, but often requires harsh reaction conditions, thus being environmentally unfriendly. Enzymatic catalysis offers a promising solution for recycling under mild conditions, but it faces inherent limitations such as poor stability, high cost, and narrow substrate applicability. Biomimetic catalysis may provide a new avenue by combining high enzyme-like activity with the stability of inorganic materials. Biomimetic catalysis has demonstrated great potential in biomass conversion and has recently shown promising progress in plastic degradation. This perspective discusses biomimetic catalysis for plastic degradation from two perspectives: the imitation of the active centers and the imitation of the substrate-binding clefts. Given the chemical similarity between biomass and plastics, relevant work is also included in the discussion to draw inspiration. We conclude this perspective by highlighting the challenges and opportunities in achieving sustainable plastic recycling via a biomimetic approach.

Bi-Interlayer Strategy for Modulating NiCoP-Based Heterostructure toward High-Performance Aqueous Energy Storage Devices.

Nickel-cobalt (NiCo) phosphides (NCPs) possess high electrochemical activity, which makes them promising candidates for electrode materials in aqueous energy storage devices, such as supercapacitors and zinc (Zn) batteries. However, the actual specific capacitance and rate capability of NCPs require further improvement, which can be achieved through reasonable heterostructural design and loading conditions of active materials on substrates. Herein, novel hierarchical Bi-NCP heterogeneous structures with built-in electric fields consisting of bismuth (Bi) interlayers (electrodeposited on carbon cloth (CC)) are designed and fabricated to ensure the formation of uniform high-load layered active materials for efficient charge and ion transport. The resulting CC/Bi-NCP electrodes show a uniform, continuous, and high mass loading (>3.5 mg) with a superior capacitance reaching 1200 F g-1 at 1 A g-1 and 4129 mF cm-2 at 1 mA cm-2 combined with high-rate capability and durable cyclic stability. Moreover, assembled hybrid supercapacitors (HSCs), supercapatteries, and alkaline Zn-ion (AZBs) batteries constructed using these electrodes deliver high energy densities of 64.4, 81.8, and 319.1 Wh kg-1, respectively. Overall, the constructed NCPs with excellent aqueous energy storage performance have the potential for the development of novel transition metal-based heterostructure electrodes for advanced energy devices.

A H2O2 Self-Charging Zinc Battery with Ultrafast Power Generation and Storage.

Self-charging power systems are considered as promising alternatives for off-grid energy devices to provide sustained electricity supply. However, the conventional self-charging systems are severely restricted by the energy availability and time-consuming charging process as well as insufficient capacity. Herein, we developed an ultrafast H2O2 self-charging aqueous Zn/NaFeFe(CN)6 battery, which simultaneously integrates the H2O2 power generation and energy storage into a battery configuration. In such battery, the chemical energy conversion of H2O2 can generate electrical energy to self-charge the battery to 1.7 V through the redox reaction between H2O2 and NaFeFe(CN)6 cathode. The thermodynamically and kinetically favorable redox reaction contributes to the ultrafast H2O2 self-charging rate and the extremely short self-charging time within 60 seconds. Moreover, the rapid H2O2 power generation can promptly compensate the energy consumption of battery to provide continuous electricity supply. Impressively, this self-charging battery shows excellent scalability of device architecture and can be designed to a H2O2 single-flow battery of 7.06 Ah to extend the long-term energy supply. This work not only provides a route to design self-charging batteries with fast charging rate and high capacity, but also pushes forward the development of self-charging power systems for advanced large-scale energy storage applications.

Towards More Sustainable Aqueous Zinc-Ion Batteries.

Aqueous zinc-ion batteries (AZIBs) are considered as the promising candidates for large-scale energy storage because of their high safety, low cost and environmental benignity. The large-scale applications of AZIBs will inevitably result in a large amount of spent AZIBs, which not only induce the waste of resources, but also pose environmental risks. Therefore, sustainable AZIBs have to be considered to minimize the risk of environmental pollution and maximize the utilization of spent compounds. Herein, this minireview focuses on the sustainability of AZIBs from material design and recycling techniques. The structure and degradation mechanism of AZIBs are discussed to guide the recycling design of the materials. Subsequently, the sustainability of component materials in AZIBs is further analysed to pre-evaluate their recycling behaviors and mentor the selection of more sustainable component materials, including active materials in cathodes, Zn anodes, and aqueous electrolytes, respectively. According to the features of component materials, corresponding green and economic approaches are further proposed to realize the recycling of active materials in cathodes, Zn anodes and electrolytes, respectively. These advanced technologies endow the recycling of component materials with high efficiency and a closed-loop control, ensuring that AZIBs will be the promising candidates of sustainable energy storage devices. This review will offer insight into potential future directions in the design of sustainable AZIBs.

Enhancing H2O2 Electrosynthesis at Industrial-Relevant Current in Acidic Media on Diatomic Cobalt Sites.

Electrocatalytic synthesis of hydrogen peroxide (H2O2) in acidic media is an efficient and eco-friendly approach to produce inherently stable H2O2, but limited by the lack of selective and stable catalysts under industrial-relevant current densities. Herein, we report a diatomic cobalt catalyst for two-electron oxygen reduction to efficiently produce H2O2 at 50-400 mA cm-2 in acid. Electrode kinetics study shows a >95% selectivity for two-electron oxygen reduction on the diatomic cobalt sites. In a flow cell device, a record-high production rate of 11.72 mol gcat-1 h-1 and exceptional long-term stability (100 h) are realized under high current densities. In situ spectroscopic studies and theoretical calculations reveal that introducing a second metal into the coordination sphere of the cobalt site can optimize the binding strength of key H2O2 intermediates due to the downshifted d-band center of cobalt. We also demonstrate the feasibility of processing municipal plastic wastes through decentralized H2O2 production.

Asiaticoside exerts neuroprotection through targeting NLRP3 inflammasome activation.

BACKGROUND: Parkinson's disease (PD), a neurodegenerative disorder, is characterized by motor symptoms due to the progressive loss of dopaminergic neurons in the substantia nigra (SN) and striatum (STR), alongside neuroinflammation. Asiaticoside (AS), a primary active component with anti-inflammatory and neuroprotective properties, is derived from Centella asiatica. However, the precise mechanisms through which AS influences PD associated with inflammation are not yet fully understood. PURPOSE: This study aimed to explore the protective mechanism of AS in PD. METHODS: Targets associated with AS and PD were identified from the Swiss Target Prediction, Similarity Ensemble Approach, PharmMapper, and GeneCards database. A protein-protein interaction (PPI) network was constructed to identify potential therapeutic targets. Concurrently, GO and KEGG analyses were performed to predict potential signaling pathways. To validate these mechanisms, the effects of AS on 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD in mice were investigated. Furthermore, neuroinflammation and the activation of the NLRP3 inflammasome were assessed to confirm the anti-inflammatory properties of AS. In vitro experiments in BV2 cells were then performed to investigate the mechanisms of AS in PD. Moreover, CETSA, molecular docking, and molecular dynamics simulations (MDs) were performed for further validation. RESULTS: Network pharmacology analysis identified 17 potential targets affected by AS in PD. GO and KEGG analyses suggested the biological roles of these targets, demonstrating that AS interacts with 149 pathways in PD. Notably, the NOD-like receptor signaling pathway was identified as a key pathway mediating AS's effect on PD. In vivo studies demonstrated that AS alleviated motor dysfunction and reduced the loss of dopaminergic neurons in MPTP-induced PD mice. In vitro experiments demonstrated that AS substantially decreased IL-1ß release in BV2 cells, attributing this to the modulation of the NLRP3 signaling pathway. CETSA and molecular docking studies indicated that AS forms a stable complex with NLRP3. MDs suggested that ARG578 played an important role in the formation of the complex. CONCLUSION: In this study, we first predicted that the potential target and pathway of AS's effect on PD could be NLRP3 protein and NOD-like receptor signaling pathway by network pharmacology analysis. Further, we demonstrated that AS could alleviate symptoms of PD induced by MPTP through its interaction with the NLRP3 protein for the first time by in vivo and in vitro experiments. By binding to NLRP3, AS effectively inhibits the assembly and activation of the inflammasome. These findings suggest that AS is a promising inhibitor for PD driven by NLRP3 overactivation.

Ginsenosides from Panax ginseng as potential therapeutic candidates for the treatment of inflammatory bowel disease.

BACKGROUND: Inflammatory bowel disease (IBD) is characterized by a chronic inflammation of the intestine, which significantly affects patients' quality of life. As a perennial plant with the homology of medicine and food, Panax ginseng is known for its substantial anti-inflammatory effects in various inflammatory disorders. Ginsenosides, the main bioactive compounds of P. ginseng, are recognized for their efficacy in ameliorating inflammation. PURPOSE: Over the past decade, approximately 150 studies have investigated the effects of P. ginseng and ginsenosides on IBD treatment and new issues have arisen. However, there has yet to be a comprehensive review assessing the potential roles of ginsenosides in IBD therapy. METHOD: This manuscript strictly adheres to the PRISMA guidelines, thereby guaranteeing systematic synthesis of data. The research articles referenced were sourced from major scientific databases, including Google Scholar, PubMed, and Web of Science. The search strategy employed keywords such as "ginsenoside", "IBD", "colitis", "UC", "inflammation", "gut microbiota", and "intestinal barrier". For image creation, Figdraw 2.0 was methodically employed. RESULTS: Treatment with various ginsenosides markedly alleviated clinical IBD symptoms. These compounds have been observed to restore intestinal epithelia, modulate cellular immunity, regulate gut microbiota, and suppress inflammatory signaling pathways. CONCLUSION: An increasing body of research supports the potential of ginsenosides in treating IBD. Ginsenosides have emerged as promising therapeutic agents for IBD, attributed to their remarkable efficacy, safety, and absence of side effects. Nevertheless, their limited bioavailability presents a substantial challenge. Thus, efforts to enhance the bioavailability of ginsenosides represent a crucial and promising direction for future IBD research.

The Construction of Anion-Induced Solvation Structures in Low-concentration Electrolyte for Stable Zinc Anodes.

Aqueous zinc-ion batteries (ZIBs) are promising large-scale energy storage devices because of their low cost and high safety. However, owing to the high activity of H2O molecules in electrolytes, hydrogen evolution reaction and side reactions usually take place on Zn anodes. Herein, additive-free PCA-Zn electrolyte with capacity of suppressing the activity of free and solvated H2O molecules was designed by selecting the cationophilic and solventophilic anions. In such electrolyte, contact ion-pairs and solvent-shared ion-pairs were achieved even at low concentration, where PCA- anions coordinate with Zn2+ and bond with solvated H2O molecules. Simultaneously, PCA- anions also induce the construction of H-bonds between free H2O molecules and them. Therefore, the activity of free and solvated H2O molecules is effectively restrained. Furthermore, since PCA- anions possess a strong affinity with metal Zn, they can also adsorb on Zn anode surface to protect Zn anode from the direct contact of H2O molecules, inhibiting the occurrence of water-triggered side reactions. As a result, plating/stripping behavior of Zn anodes is highly reversible and the coulombic efficiency can reach to 99.43 % in PCA-Zn electrolyte. To illustrate the feasibility of PCA-Zn electrolyte, the Zn||PANI full batteries were assembled based on PCA-Zn electrolyte and exhibited enhanced cycling performance.

A High-Energy Aqueous All-Sulfur Battery.

Rechargeable aqueous batteries are promising energy storage devices because of their high safety and low cost. However, their energy densities are generally unsatisfactory due to the limited capacities of ion-inserted electrode materials, prohibiting their widespread applications. Herein, a high-energy aqueous all-sulfur battery was constructed via matching S/Cu2 S and S/CaSx redox couples. In such batteries, both cathodes and anodes undergo the conversion reaction between sulfur/metal sulfides redox couples, which display high specific capacities and rational electrode potential difference. Furthermore, during the charge/discharge process, the simultaneous redox of Cu2+ ion charge-carriers also takes place and contributes to a more two-electron transfer, which doubles the capacity of cathodes. As a result, the assembled aqueous all-sulfur batteries deliver a high discharge capacity of 447 mAh g-1 based on total mass of sulfur in cathode and anode at 0.1 A g-1 , contributing to an enhanced energy density of 393 Wh kg-1 . This work will widen the scope for the design of high-energy aqueous batteries.

The Construction of Binary Phase Electrolyte Interface for Highly Stable Zinc Anodes.

Metal zinc is a promising anode candidate of aqueous zinc-ion batteries due to high theoretical capacity, low cost, and high safety. However, it often suffers from hydrogen evolution reaction (HER), dendrite growth, and formation of by-products. Herein, a triethyl phosphate (TEP)/H2 O binary phase electrolyte (BPE) interface is developed by introducing TEP-based electrolyte-wetted hydrophobic polypropylene (PP) separator onto the Zn anode surface. The equilibrium of the BPE interface depends on the comparable surface tensions of H2 O-based and TEP-based electrolytes on hydrophobic PP separator surfaces. The BPE interface induces Zn2+ solvation structure conversion from [Zn(H2 O)x ]2+ to [Zn(TEP)n (H2 O)y ]2+ , where most solvated H2 O molecules are removed. In [Zn(TEP)n (H2 O)y ]2+ , the residual H2 O molecules can be further constrained by the formation of H bonds between TEP and H2 O molecules. Consequently, the ionization of solvated H2 O molecules is effectively suppressed, and HER and by-products are effectively restricted on Zn anode surfaces in BPE. As a result, Zn anodes exhibit a high Coulombic efficiency of 99.12% and superior cycling performance of 6000 h, which is much higher than the case in single-phase aqueous electrolytes. To illustrate the feasibility of BPE in full cells, the Zn/Alx V2 O5 batteries are assembled based on the BPE and exhibited enhanced cycling performance.

Fecal fermentation behavior and immunomodulatory activity of arabinoxylan from wheat bran.

Arabinoxylan (AX) is the predominant non-starch polysaccharide in wheat bran, known for its significant immunomodulatory activity. However, existing literature lacks comprehensive studies on AX fermentation by gut microbiota and its subsequent immunomodulatory mechanisms. In the present study, we aimed to investigate the effects of AX on the composition of gut microbiota and the characteristics of its immunomodulatory activity. For this purpose, an in vitro fermentation system and a cyclophosphamide-induced immunosuppressed mouse model were established to explore both the in vitro and in vivo effects of AX on gut microbiota and immune modulation. The results demonstrated that AX was metabolized by gut microbes and in turn to promoting the production of short-chain fatty acids (SCFAs), which concurrently led to a significant decrease in pH. Furthermore, AX treatment significantly changed the microbial composition, elevated the relative abundance of Actinobacteria while reducing that of Bacteroidetes. In the immunosuppressed mice, AX administration improved the thymus and spleen indices, mitigated spleen injury, and bolstered overall immunity. Moreover, AX altered the gut microbiota structure, increasing the abundance of Bacteroidetes and decreasing that of Firmicutes. These findings suggest that wheat bran-derived AX can modulate intestinal microbial composition, improve gut microecology, and enhance host immunity by targeting gut microbiota.

An Ultrafast Air Self-Charging Zinc Battery.

Air self-charging power systems possess the capability of energy harvesting, conversion, and storage simultaneously. However, in general, their self-charging rate is slow and the batteries cannot be oxidized to the fully charged state due to the weak oxidizability of O2 . Herein, an ultrafast air self-charging aqueous zinc battery is designed by constructing a polyaniline@Pt/C (PANI@Pt/C) composite cathode. The introduction of Pt/C catalyst endows the redox reaction between PANI and O2 with fast reaction kinetics and extended redox potential difference. Therefore, the self-charging rate of the Zn/PANI@Pt/C batteries is effectively accelerated and they can be self-charged to fully charged state. Furthermore, the PANI can be recharged by O2 simultaneously during discharging process to compensate the consumed electrical energy, achieving prolonged energy supply. In addition, the PANI@Pt/C cathodes can be directly used as the cathodes of flexible self-charging zinc batteries due to their excellent mechanical properties. As a proof of concept, flexible soft-packaged Zn/PANI@Pt/C batteries are fabricated and displayed stable electrochemical performance and self-rechargeability even at different bending states. A route is provided here to design ultrafast chemical self-charging energy storage devices and the horizons of flexible energy storage devices are broadened.

Diatomic iron nanozyme with lipoxidase-like activity for efficient inactivation of enveloped virus.

Enveloped viruses encased within a lipid bilayer membrane are highly contagious and can cause many infectious diseases like influenza and COVID-19, thus calling for effective prevention and inactivation strategies. Here, we develop a diatomic iron nanozyme with lipoxidase-like (LOX-like) activity for the inactivation of enveloped virus. The diatomic iron sites can destruct the viral envelope via lipid peroxidation, thus displaying non-specific virucidal property. In contrast, natural LOX exhibits low antiviral performance, manifesting the advantage of nanozyme over the natural enzyme. Theoretical studies suggest that the Fe-O-Fe motif can match well the energy levels of Fe2 minority ß-spin d orbitals and pentadiene moiety π* orbitals, and thus significantly lower the activation barrier of cis,cis-1,4-pentadiene moiety in the vesicle membrane. We showcase that the diatomic iron nanozyme can be incorporated into air purifier to disinfect airborne flu virus. The present strategy promises a future application in comprehensive biosecurity control.

Six-Electron-Redox Iodine Electrodes for High-Energy Aqueous Batteries.

Iodine (I2 ) shows great promising as the active material in aqueous batteries due to its distinctive merits of high abundance in ocean and low cost. However, in conventional aqueous I2 -based batteries, the energy storage mechanism of I- /I2 conversion is only two-electron redox reaction, limiting their energy density. Herein, six-electron redox chemistry of I2 electrodes is achieved via the synergistic effect of redox-ion charge-carriers and halide ions in electrolytes. The redox-active Cu2+ ions in electrolytes induce the conversion between Cu2+ ions and I2 to CuI at low potential. Simultaneously, the Cl- ions in electrolytes activate the I2 /ICl redox couple at high potential. As a result, in our case, I2 -based battery system with six-electron redox is developed. Such energy storage mechanism with six-electron redox leads to high discharge potential and capacity, excellent rate capability, as well as stable cycling behavior of I2 electrodes. Impressively, six-electron-redox I2 cathodes can match various aqueous metal (e.g. Zn, Mn and Fe) anodes to construct metal||I2 hybrid batteries. These hybrid batteries not only deliver enhanced capacities, but also exhibit higher operate voltages, which contributes to superior energy densities. Therefore, this work broadens the horizon for the design of high-energy aqueous I2 -based batteries.

High-Energy Aqueous/Organic Hybrid Batteries Enabled by Cu2+ Redox Charge Carriers.

Lithium||sulfur (Li||S) batteries are considered as one of the promising next-generation batteries due to the high theoretical capacity and low cost of S cathodes, as well as the low redox potential of Li metal anodes (-3.04 V vs. standard hydrogen electrode). However, the S reduction reaction from S to Li2 S leads to limited discharge voltage and capacity, largely hindering the energy density of Li||S batteries. Herein, high-energy Li||S hybrid batteries were designed via an electrolyte decoupling strategy. In cathodes, S electrodes undergo the solid-solid conversion reaction from S to Cu2 S with four-electron transfer in a Cu2+ -based aqueous electrolyte. Such an energy storage mechanism contributes to enhanced electrochemical performance of S electrodes, including high discharge potential and capacity, superior rate performance and stable cycling behavior. As a result, the assembled Li||S hybrid batteries exhibit a high discharge voltage of 3.4 V and satisfactory capacity of 2.3 Ah g-1 , contributing to incredible energy density. This work provides an opportunity for the construction of high-energy Li||S batteries.

Terrace-Rich Ultrathin PtCu Surface on Earth-Abundant Metal for Oxygen Reduction Reaction.

The activity and stability of the platinum electrode toward the oxygen reduction reaction are size-dependent. Although small nanoparticles have high Pt utilization, the undercoordinated Pt sites on their surface are assumed to have too strong oxygen binding strength, thus often leading to compromised activity and surface instability. Herein, we report an extended nanostructured PtCu ultrathin surface to reduce the number of low-coordination sites without sacrificing the electrochemical active surface area (ECSA). The surface shows (111)-oriented characteristics, as proven by electrochemical probe reactions and spectroscopies. The PtCu surface brings over an order of magnitude increase in specific activity relative to commercial Pt/C and nearly 4-fold enhancement in ECSA compared to traditional thin films. Moreover, due to the weak absorption of air impurities (e.g., SO2, NO, CO) on highly coordinated sites, the catalyst displays enhanced contaminant tolerance compared with nanoparticulate Pt/C. This work promises a broad screening of extended nanostructured surface catalysts for electrochemical conversions.

PET recycling under mild conditions via substituent-modulated intramolecular hydrolysis.

Catalytic depolymerization represents a promising approach for the closed-loop recycling of plastic wastes. Here, we report a knowledge-driven catalyst development for poly(ethylene terephthalate) (PET) recycling, which not only achieves more than 23-fold enhancement in specific activity but also reduces the alkali concentration by an order of magnitude compared with the conventional hydrolysis. Substituted binuclear zinc catalysts are developed to regulate biomimetic intramolecular PET hydrolysis. Hammett studies and density functional theory (DFT) calculations indicate that the substituents modify the charge densities of the active centers, and an optimal substituent should slightly increase the electron richness of the zinc sites to facilitate the formation of a six-membered ring intermediate. The understanding of the structure-activity relationship leads to an advanced catalyst with a specific activity of 778 ± 40 gPET h-1 gcatal-1 in 0.1 M NaOH, far outcompeting the conventional hydrolysis using caustic bases (<33.3 gPET h-1 gcatal-1 in 1-5 M NaOH). This work opens new avenues for environmentally benign PET recycling.

The potential of Panax notoginseng against COVID-19 infection.

The COVID-19 pandemic has changed the world and has presented the scientific community with unprecedented challenges. Infection is associated with overproduction of proinflammatory cytokines secondary to hyperactivation of the innate immune response, inducing a cytokine storm and triggering multiorgan failure and significant morbidity/mortality. No specific treatment is yet available. For thousands of years, Panax notoginseng has been used to treat various infectious diseases. Experimental evidence of P. notoginseng utility in terms of alleviating the cytokine storm, especially the cascade, and improving post-COVID-19 symptoms, suggests that P. notoginseng may serve as a valuable adjunct treatment for COVID-19 infection.

Synergetic modulation on ionic association and solvation structure by electron-withdrawing effect for aqueous zinc-ion batteries.

Aqueous zinc-ion batteries are emerging as one of the most promising large-scale energy storage systems due to their low cost and high safety. However, Zn anodes often encounter the problems of Zn dendrite growth, hydrogen evolution reaction, and formation of by-products. Herein, we developed the low ionic association electrolytes (LIAEs) by introducing 2, 2, 2-trifluoroethanol (TFE) into 30 m ZnCl2 electrolyte. Owing to the electron-withdrawing effect of -CF3 groups in TFE molecules, in LIAEs, the Zn2+ solvation structures convert from larger aggregate clusters into smaller parts and TFE will construct H-bonds with H2O in Zn2+ solvation structure simultaneously. Consequently, ionic migration kinetics are significantly enhanced and the ionization of solvated H2O is effectively suppressed in LIAEs. As a result, Zn anodes in LIAE display a fast plating/stripping kinetics and high Coulombic efficiency of 99.74%. The corresponding full batteries exhibit an improved comprehensive performance such as high-rate capability and long cycling life.

General Synthesis of a Diatomic Catalyst Library via a Macrocyclic Precursor-Mediated Approach.

Heterogeneous catalysts containing diatomic sites are often hypothesized to have distinctive reactivity due to synergistic effects, but there are limited approaches that enable the convenient production of diatomic catalysts (DACs) with diverse metal combinations. Here, we present a general synthetic strategy for constructing a DAC library across a wide spectrum of homonuclear (Fe2, Co2, Ni2, Cu2, Mn2, and Pd2) and heteronuclear (Fe-Cu, Fe-Ni, Cu-Mn, and Cu-Co) bimetal centers. This strategy is based on an encapsulation-pyrolysis approach, wherein a porous material-encapsulated macrocyclic complex mediates the structure of DACs by preserving the main body of the molecular framework during pyrolysis. We take the oxygen reduction reaction (ORR) as an example to show that this DAC library can provide great opportunities for electrocatalyst development by unlocking an unconventional reaction pathway. Among all investigated sites, Fe-Cu diatomic sites possess exceptional high durability for ORR because the Fe-Cu pairs can steer elementary steps in the catalytic cycle and suppress the troublesome Fenton-like reactions.