Ultra-thin and Mechanically Stable LiCoO2 -Electrolyte Interphase Enabled by Mg2+ Involved Electrolyte.

LiCoO2 (LCO) cathode materials have attracted significant attention for its potential to provide higher energy density in current Lithium-ion batteries (LIBs). However, the structure and performance degradation are exacerbated by increasing voltage due to the catastrophic reaction between the applied electrolyte and delithiated LCO. The present study focuses on the construction of physically and chemically robust Mg-integrated cathode-electrolyte interface (MCEI) to address this issue, by incorporating Magnesium bis(trifluoromethanesulfonyl)imide (Mg[TFSI]2 ) as an electrolyte additive. During formation cycles, the strong MCEI is formed and maintained its 2 nm thickness throughout long-term cycling. Notably, Mg is detected not only in the robust MCEI, but also imbedded in the surface of the LCO lattice. As a result, the parasitic interfacial side reactions, surface phase reconstruction, particle cracking, Co dissolution and shuttling are considerably suppressed, resulting in long-term cycling stability of LCO up to 4.5 V. Therefore, benefit from the double protection of the strong MCEI, the Li||LCO coin cell and the Ah-level Graphite||LCO pouch cell exhibit high capacity retention by using Mg-electrolyte, which are 88.13% after 200 cycles and 90.4% after 300 cycles, respectively. This work provides a novel approach for the rational design of traditional electrolyte additives.

Well-dispersed Pt/Nb2O5on zeolitic imidazolate framework derived nitrogen-doped carbon for efficient oxygen reduction reaction.

In this work, an advanced hybrid material was constructed by incorporating niobium pentoxide (Nb2O5) nanocrystals with nitrogen-doped carbon (NC) derived from ZIF-8 dodecahedrons, serving as a support, referred to as Nb2O5/NC. Pt nanocrystals were dispersed onto Nb2O5/NC using a simple impregnation reduction method. The obtained Pt/Nb2O5/NC electrocatalyst showed high oxygen reduction reaction (ORR) activity due to three-phase mutual contacting structure with well-dispersed Pt and Nb2O5NPs. In addition, the conductive NC benefits electron transfer, while the induced Nb2O5can regulate the electronic structure of Pt element and anchor Pt nanocrystals, thereby enhancing the ORR activity and stability. The half-wave potential (E1/2) for Pt/Nb2O5/NC is 0.886 V, which is higher than that of Pt/NC (E1/2= 0.826 V). The stability examinations demonstrated that Pt/Nb2O5/NC exhibited higher electrocatalytic durability than Pt/NC. Our work provides a new direction for synthesis and structural design of precious metal/oxides hybrid electrocatalysts.

Creating High-entropy Single Atoms on Transition Disulfides through Substrate-induced Redox Dynamics for Efficient Electrocatalytic Hydrogen Evolution.

The controllable anchoring of multiple metal single-atoms (SAs) into a single support exhibits scientific and technological opportunities,while marrying the concentration-complex multimetallic SAs and high-entropy SAs (HESAs) into one SAC system remains a substantial challenge.Here, we present a substrate-mediated SAs formation strategy to successfully fabricate a library of multimetallic SAs and HESAs on MoS2 and MoSe2 supports, which can precisely control the doping location of SAs. Specially, the contents of SAs can continuously increase until the accessible Mo atoms on TMDs carriers are completely replaced by SAs, thus allowing the of much higher metal contents.In-depth mechanistic study shows that the well-controlled synthesis of multimetallic SAs and HESAs is realized by controlling the reversible redox reaction occurred on the TMDs/TM ion interface.As a proof-of-concept application, a variety of SAs-TMDs were applied to hydrogen evolution reaction. The optimized HESAs-TMDs (Pt,Ru,Rh,Pd,Re-MoSe2) delivers a much higher activity and durability than state of-the-art Pt. Thus, our work will broaden the family of single-atom catalysts and provide a new guideline for the rational design of high-performance single-atom catalysts.

Foldback-crRNA-Enhanced CRISPR/Cas13a System (FCECas13a) Enables Direct Detection of Ultrashort sncRNA.

The CRISPR/Cas13a system has promising applications in clinical small noncoding RNA (sncRNA) detection because it is free from the interference of genomic DNA. However, detecting ultrashort sncRNAs (less than 20 nucleotides) has been challenging because the Cas13a nuclease requires longer crRNA-target RNA hybrids to be activated. Here, we report the development of a foldback-crRNA-enhanced CRISPR/Cas13a (FCECas13a) system that overcomes the limitations of the current CRISPR/Cas13a system in detecting ultrashort sncRNAs. The FCECas13a system employs a 3'-terminal foldback crRNA that hybridizes with the target ultrashort sncRNA, forming a double strand that "tricks" the Cas13a nuclease into activating the HEPN structural domain and generating trans-cleavage activity. The FCECas13a system can accurately detect miRNA720 (a sncRNA currently known as tRNA-derived small RNA), which is only 17 nucleotides long and has a concentration as low as 15 fM within 20 min. This FCECas13a system opens new avenues for ultrashort sncRNA detection with significant implications for basic biological research, disease prognosis, and molecular diagnosis.

Building Atomic Scale and Dense Fe─N4 Edge Sites of Highly Efficient Fe─N─C Oxygen Reduction Catalysts Using a Sacrificial Bimetallic Pyrolysis Strategy.

Replacing high-cost and scarce platinum (Pt) with transition metal and nitrogen co-doped carbon (M/N/C, M = Fe, Co, Mn, and so on) catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells has largely been impeded by the unsatisfactory ORR activity of M/N/C due to the low site utilization and inferior intrinsic activity of the M─N4 active center. Here, these limits are overcome by using a sacrificial bimetallic pyrolysis strategy to synthesize Fe─N─C catalyst by implanting the Cd ions in the backbone of ZIF-8, leading to exposure of inaccessible FeN4 edge sites (that is, increasing active site density (SD)) and high fast mass transport at the catalyst layer of cathode. As a result, the final obtained Fe(Cd)─N─C catalyst has an active site density of 33.01 µmol g-1 (with 33.01% site utilization) over 5.8 times higher than that of Fe─N─C catalyst. Specially, the optimal catalyst delivers a high ORR performance with a half-wave potential of 0.837 (vs RHE) in a 0.1 m HClO4 electrolyte, which surpasses most of Fe-based catalysts.

Engineering Energy Level of FeN4 Sites via Dual-Atom Site Construction Toward Efficient Oxygen Reduction.

Single-atom catalysts based on metal-N4 moieties and embedded in a graphite matrix (defined as MNC) are promising for oxygen reduction reaction (ORR). However, the performance of MNC catalysts is still far from satisfactory due to their imperfect adsorption energy to oxygen species. Herein, single-atom FeNC is leveraged as a model system and report an adjacent Ru-N4 moiety modulation effect to optimize the catalyst's electronic configuration and ORR performance. Theoretical simulations and physical characterizations reveal that the incorporation of Ru-N4 sites as the modulator can alter the d-band electronic energy of Fe center to weaken the FeO binding affinity, thus resulting in the lower adsorption energy of ORR intermediates at Fe sites. Thanks to the synergetic effects of neighboring Fe and Ru single-atom pairs, the FeN4 /RuN4 catalyst exhibits a half-wave potential of 0.958 V and negligible activity degradation after 10 000 cycles in 0.1 m KOH. Metal-air batteries using this catalyst in the cathode side exhibit a high power density of 219.5 mW cm-2 and excellent cycling stability for over 2370 h, outperforming the state-of-the-art catalysts.

NLRP3 inflammasome activation contributes to fungal clearance and lung injury during Talaromyces marneffei infection.

The increased levels of IL-1ß and IL-18 cytokines have been associated with the severity of sepsis and outcomes of patients infected with Talaromyces marneffei. Previous studies have suggested that NLRP3 plays an important role in caspase-1 activated secretion of IL-1ß and IL-18 in fungal-infected macrophages. In the present study, the role of the NLRP3 inflammasome in talaromycosis is investigated in an in vitro assay and in vivo with a mice systemic infection model. We found that the NLRP3 inflammasome pathway in infected mice is activated along with increased production of IL-1ß. Such an activation of the NLRP3 inflammasome is also observed in either mice or human macrophages challenged with T. marneffei conidia. Our results indicate that IL-1ß release by infected macrophages is NLRP3 inflammasome-dependent and NLRP3 contributes to death of mice at the early stage of pulmonary infection. Moreover, a greater number of MPO-positive cells are found in the lungs of infected Nlrp3-/- mice and WT mice with reduced LDH levels, especially at the last stage of infection. Therefore, we conclude that the NLRP3 Inflammasome activation is important for fungal clearance, neutrophil recruitment and lung injury during T. marneffei Infection.

Enhanced electrocatalytic performance for oxygen evolution reaction via active interfaces of Co3O4arrays@FeOx/Carbon cloth heterostructure by plasma-enhanced atomic layer deposition.

Oxygen evolution reaction (OER) is a necessary procedure in various devices including water splitting and rechargeable metal-air batteries but required a higher potential to improve oxygen evolution efficiency due to its slow reaction kinetics. In order to solve this problem, a heterostructured electrocatalyst (Co3O4@FeOx/CC) is synthesized by deposition of iron oxides (FeOx) on carbon cloth (CC) via plasma-enhanced atomic layer deposition, then growth of the cobalt oxide (Co3O4) nanosheet arrays. The deposition cycle of FeOxon the CC strongly influences thein situgrowth and distribution of Co3O4nanosheets and electronic conductivity of the electrocatalyst. Owing to the high accessible and electroactive areas and improved electrical conductivity, the free-standing electrode of Co3O4@FeOx/CC with 100 deposition cycles of FeOxexhibits excellent electrocatalytic performance for OER with a low overpotential of 314.0 mV at 10 mA cm-2and a small Tafel slope of 29.2 mV dec-1in alkaline solution, which is much better than that of Co3O4/CC (448 mV), and even commercial RuO2(380 mV). This design and optimization strategy shows a promising way to synthesize ideally designed catalytic architectures for application in energy storage and conversion.

Ruthenium Complexes as Promising Candidates against Lung Cancer.

Lung cancer is one of the most common malignancies with the highest mortality rate and the second-highest incidence rate after breast cancer, posing a serious threat to human health. The accidental discovery of the antitumor properties of cisplatin in the early 1960s aroused a growing interest in metal-based compounds for cancer treatment. However, the clinical application of cisplatin is limited by serious side effects and drug resistance. Therefore, other transition metal complexes have been developed for the treatment of different malignant cancers. Among them, Ru(II/III)-based complexes have emerged as promising anticancer drug candidates due to their potential anticancer properties and selective cytotoxic activity. In this review, we summarized the latest developments of Ru(II/III) complexes against lung cancer, focusing mainly on the mechanisms of their biological activities, including induction of apoptosis, necroptosis, autophagy, cell cycle arrest, inhibition of cell proliferation, and invasion and metastasis of lung cancer cells.

Sulfur-Coordinated Organoiridium(III) Complexes Exert Breast Anticancer Activity via Inhibition of Wnt/ß-Catenin Signaling.

The sulfur-coordinated organoiridium(III) complexes pbtIrSS and ppyIrSS, which contain C,N and S,S (dithione) chelating ligands, were found to inhibit breast cancer tumorigenesis and metastasis by targeting Wnt/ß-catenin signaling for the first time. Treatment with pbtIrSS and ppyIrSS induces the degradation of LRP6, thereby decreasing the protein levels of DVL2, ß-catenin and activated ß-catenin, resulting in downregulation of Wnt target genes CD44 and survivin. Additionally, pbtIrSS and ppyIrSS can suppress cell migration and invasion of breast cancer cells. Furthermore, both complexes show the ability to inhibit sphere formation and mediate the stemness properties of breast cancer cells. Importantly, pbtIrSS exerts potent anti-tumor and anti-metastasis effects in mouse xenograft models through the blockage of Wnt/ß-catenin signaling. Taken together, our results indicate that pbtIrSS has great potential to be developed as a breast cancer therapeutic agent with a novel mechanism.

Slower Removing Ligands of Metal Organic Frameworks Enables Higher Electrocatalytic Performance of Derived Nanomaterials.

The widely used route of high-temperature pyrolysis for transformation of Prussian blue analogs (PBAs) to functional nanomaterials leads to the fast removal of CN- ligands, and thus the formation of large metal aggregates and the loss of porous structures inside PBAs. Here, a controllable pyrolysis route at low temperature is reported for retaining the confined effect of CN- ligands to metal cations during the whole pyrolysis process, thereby preparing high-surface-area cubes comprising disordered bimetallic oxides (i.e., Co3 O4 and Fe2 O3 ) nanoparticles. The disordered structure of Co3 O4 enables the exposure of abundant oxygen vacancies. Notably, for the first time, it is found that the in situ generated CoOOH during the oxygen evolution reaction (OER) can inherit the oxygen vacancies of pristine Co3 O4 (i.e., before OER), and such CoOOH with abundant oxygen vacancies adsorbs two - OH in the following Co3+ to Co4+ for markedly promoting OER. However, during the similar step, the ordered Co3 O4 with less oxygen vacancies only involves one - OH, resulting in the additional overpotentials for adsorbing - OH. Consequently, with high surface area and disordered Co3 O4 , the as-synthesized electrocatalysts have a low potential of 237 mV at 10 mA cm-2 , surpassing most of reported electrocatalysts.

Nonmetal Doping as a Robust Route for Boosting the Hydrogen Evolution of Metal-Based Electrocatalysts.

Recently, nonmetal doping has exhibited its great potential for boosting the hydrogen evolution reaction (HER) of transition-metal (TM)-based electrocatalysts. To this end, this work overviews the recent achievements made on the design and development of the nonmetal-doped TM-based electrocatalysts and their performance for the HER. It is also shown that by rationally doping nonmetal elements, the electronic structures of TM-based electrocatalysts can be effectively tuned and in turn the Gibbs free energy of the TM for adsorption of H* intermediates (ΔGH* ) optimized, consequently enhancing the intrinsic activity of TM-based electrocatalysts. Notably, we highlight that concurrently doping two nonmetal elements can continuously and precisely regulate the electronic structures of the TM, thereby maximizing the activity for HER. Moreover, nonmetal doping also accounts for enhancing the physical properties of the TM (i.e. surface area). Therefore, nonmetal doping is a robust strategy for simultaneous regulation of the chemical and physical features of the TM.

Facile Synthesis of Sub-Nanometric Copper Clusters by Double Confinement Enables Selective Reduction of Carbon Dioxide to Methane.

Previous density-functional theory (DFT) calculations show that sub-nanometric Cu clusters (i.e., 13 atoms) favorably generate CH4 from the CO2 reduction reaction (CO2 RR), but experimental evidence is lacking. Herein, a facile impregnation-calcination route towards Cu clusters, having a diameter of about 1.0 nm with about 10 atoms, was developed by double confinement of carbon defects and micropores. These Cu clusters enable high selectivity for the CO2 RR with a maximum Faraday efficiency of 81.7 % for CH4 . Calculations and experimental results show that the Cu clusters enhance the adsorption of *H and *CO intermediates, thus promoting generation of CH4 rather than H2 and CO. The strong interactions between the Cu clusters and defective carbon optimize the electronic structure of the Cu clusters for selectivity and stability towards generation of CH4 . Provided here is the first experimental evidence that sub-nanometric Cu clusters facilitate the production of CH4 from the CO2 RR.

Scalable Production of Efficient Single-Atom Copper Decorated Carbon Membranes for CO2 Electroreduction to Methanol.

Electrocatalytic reduction reaction of CO2 (CO2RR) is an effective way to mitigate energy and environmental issues. However, very limited catalysts are capable of converting CO2 resources into high-value products such as hydrocarbons or alcohols. Herein, we first propose a facile strategy for the large-scale synthesis of isolated Cu decorated through-hole carbon nanofibers (CuSAs/TCNFs). This CuSAs/TCNFs membrane has excellent mechanical properties and can be directly used as cathode for CO2RR, which could generate nearly pure methanol with 44% Faradaic efficiency in liquid phase. The self-supporting and through-hole structure of CuSAs/TCNFs greatly reduces the embedded metal atoms and produces abundant efficient Cu single atoms, which could actually participate in CO2RR, eventually causing -93 mA cm-2 partial current density for C1 products and more than 50 h stability in aqueous solution. According to DFT calculations, Cu single atoms possess a relatively higher binding energy for *CO intermediate. Therefore, *CO could be further reduced to products like methanol, instead of being easily released from the catalyst surface as CO product. This report may benefit the design of efficient and high-yield single-atom catalysts for other electrocatalytic reactions.

Donor and Ring-Fusing Engineering for Far-Red to Near-Infrared Triphenylpyrylium Fluorophores with Enhanced Fluorescence Performance for Sensing and Imaging.

Fluorescent probes have become an indispensable tool in the detection and imaging of biological and disease-related analytes due to their sensitivity and technical simplicity. In particular, fluorescent probes with far-red to near-infrared (FR-NIR) emissions are very attractive for biomedical applications. However, many available FR-NIR fluorophores suffer from small Stokes shifts and sometimes low quantum yields, resulting in self-quenching and low contrast. In this work, we describe the rational design and engineering of FR-NIR 2,4,6-triphenylpyrylium-based fluorophores (TPP-Fluors) with the help of theoretical calculations. Our strategy is based on the appending of electron-donating substituents and fusing groups onto 2,4,6-triphenylpyrylium. In contrast to the parent TPP with short emission wavelength, weak quantum yields, and low chemical stability, the obtained novel TPP-Fluors display some favorable properties, such as long-wavelength emission, large Stokes shifts, moderate to high quantum yields, and chemical stability. TPP-Fluors demonstrate their biological value as mitochondria-specific labeling reagents due to their inherently positive nature. In addition, TPP-Fluors can also be applied to develop ratiometric fluorescent probes, as the electron-donating ability of the 2,6-phenyl substituents is closely correlated with their emission wavelength. A proof-of-concept ratiometric probe has been developed by derivatizing the amino groups of TPP-Fluor for the detection and imaging of nitroreductase in vitro and in hypoxic cells.

Superhydrophilic Phytic-Acid-Doped Conductive Hydrogels as Metal-Free and Binder-Free Electrocatalysts for Efficient Water Oxidation.

Recently, metal-free, heteroatom-doped carbon nanomaterials have emerged as promising electrocatalysts for the oxygen evolution reaction (OER), but their synthesis is a tedious process involving energy-wasting calcination. Molecular electrocatalysts offer attractive catalysts for the OER. Here, phytic acid (PA) was selected to investigate the OER activity of carbons in organic molecules by DFT calculations and experiments. Positively charged carbons on PA were very active towards the OER. The PA molecules were fixed into a porous, conductive hydrogel with a superhydrophilic surface. This outperformed most metal-free electrocatalysts. Besides the active sites on PA, the high OER activity was also related to the porous and conductive networks on the hydrogel, which allowed fast charge and mass transport during the OER. Therefore, this work provides a metal-free, organic-molecule-based electrocatalyst to replace carbon nanomaterials for efficient OER.

Boosting Electrochemical Hydrogen Evolution of Porous Metal Phosphides Nanosheets by Coating Defective TiO2 Overlayers.

Nonprecious transition metal phosphides (TMPs) have emerged as robust electrocalysts for the hydrogen evolution reaction (HER). However, the TMPs suffer from low activity for water dissociation, which greatly limits the efficiency for alkaline HER. Here, a facile yet robust strategy is reported to boost the HER of metal phosphides by coating defective TiO2 overlayers. The oxygen vacancies (Ov ) on defective TiO2 overlayers are found to possess high activity for adsorption and dissociation of water, thereby significantly promoting the initial Volmer step of HER to generate the reactive hydrogen atoms. Moreover, the porous (Co, Ni)2 P (i.e., Co2 P and Ni2 P) nanosheets provide enough active sites for adsorption and recombination of reactive hydrogen atoms to produce hydrogen gas. The catalytic synergy of (Co, Ni)2 P and Ov coupled with the hierarchically porous structure renders the porous (Co, Ni)2 P@0.1TiO2 nanosheet arrays excellent electrocatalysts for HER, showing a small overpotential (92 mV) to yield a current density of 10 mA cm-2 , a small Tafel slope (49 mV dec-1 ), and an outstanding stability. This work demonstrates a surface decoration route for enhancing the activity of nonprecious metal-based electrocatalysts for HER.

Composition Tailoring via N and S Co-doping and Structure Tuning by Constructing Hierarchical Pores: Metal-Free Catalysts for High-Performance Electrochemical Reduction of CO2.

A facile route to scalable production of N and S co-doped, hierarchically porous carbon nanofiber (NSHCF) membranes (ca. 400 cm2 membrane in a single process) is reported. As-synthesized NSHCF membranes are flexible and free-standing, allowing their direct use as cathodes for efficient electrochemical CO2 reduction reaction (CO2 RR). Notably, CO with 94 % Faradaic efficiency and -103 mA cm-2 current density are readily achieved with only about 1.2 mg catalyst loading, which are among the best results ever obtained by metal-free CO2 RR catalysts. On the basis of control experiments and DFT calculations, such outstanding CO Faradaic efficiency can be attributed to the co-doped pyridinic N and carbon-bonded S atoms, which effectively decrease the Gibbs free energy of key *COOH intermediate. Furthermore, hierarchically porous structures of NSHCF membranes impart a much higher density of accessible active sites for CO2 RR, leading to the ultra-high current density.

Enhancing the Anti-Solvatochromic Two-Photon Fluorescence for Cirrhosis Imaging by Forming a Hydrogen-Bond Network.

Two-photon imaging is an emerging tool for biomedical research and clinical diagnostics. Electron donor-acceptor (D-A) type molecules are the most widely employed two-photon scaffolds. However, current D-A type fluorophores suffer from solvatochromic quenching in aqueous biological samples. To address this issue, we devised a novel class of D-A type green fluorescent protein (GFP) chromophore analogues that form a hydrogen-bond network in water to improve the two-photon efficiency. Our design results in two-photon chalcone (TPC) dyes with 0.80 quantum yield and large two-photon action cross section (210 GM) in water. This strategy to form hydrogen bonds can be generalized to design two-photon materials with anti-solvatochromic fluorescence. To demonstrate the improved in vivo imaging, we designed a sulfide probe based on TPC dyes and monitored endogenous H2 S generation and scavenging in the cirrhotic rat liver for the first time.

Polypyrrole pre-intercalation engineering-induced NH4+ removal in tunnel ammonium vanadate toward high-performance zinc ion batteries.

Ammonium vanadate with stable bi-layered structure and superior mass-specific capacity have emerged as competitive cathode materials for aqueous rechargeable zinc-ion batteries (AZIBs). Nevertheless, fragile NH…O bonds and too strong electrostatic interaction by virtue of excessive NH4+ will lead to sluggish Zn2+ ion mobility, further largely affects the electro-chemical performance of ammonium vanadate in AZIBs. The present work incorporates polypyrrole (PPy) to partially replace NH4+ in NH4V4O10 (NVO), resulting in the significantly enlarged interlayers (from 10.1 to 11.9 Å), remarkable electronic conductivity, increased oxygen vacancies and reinforced layered structure. The partial removal of NH4+ will alleviate the irreversible deammoniation to protect the laminate structures from collapse during ion insertion/extraction. The expanded interlayer spacing and the increased oxygen vacancies by the virtue of the introduction of polypyrrole improve the ionic diffusion, enabling exceptional rate performance of NH4V4O10. As expected, the resulting polypyrrole intercalated ammonium vanadate (NVOY) presents a superior discharge capacity of 431.9 mAh g-1 at 0.5 A g-1 and remarkable cycling stability of 219.1 mAh g-1 at 20 A g-1 with 78 % capacity retention after 1500 cycles. The in-situ electrochemical impedance spectroscopy (EIS), in-situ X-ray diffraction (XRD), ex-situ X-ray photoelectron spectroscopy (XPS) and ex-situ high resolution transmission electron microscopy (HR-TEM) analysis investigate a highly reversible intercalation Zn-storage mechanism, and the enhanced the redox kinetics are related to the combined effect of interlayer regulation, high electronic conductivity and oxygen defect engineering by partial substitution NH4+ of PPy incorporation.