V-doped activated Ru/Ti2.5V0.5C2 dual-active center accelerate hydrogen production from ammonia borane.

Designing and constructing the active center of Ru-based catalysts is the key to efficient hydrolysis of ammonia borane (NH3BH3, AB) for hydrogen production. Herein, V-doped Ru/Ti2.5V0.5C2 dual-active center catalysts were synthesized, showing excellent catalytic ability for AB hydrolysis. The corresponding turnover frequency value was 1072 min-1 at 298 K, and the hydrolysis rate rB of AB was 235 × 103 mL·min-1·gRu-1. X-ray photoelectron spectroscopy results indicated that the interaction between V-doped Ti3C2 and catalytic metal Ru transfers electrons from Ti to Ru, resulting in electron-rich Ru species. According to density functional theory calculations, the activation energy and reaction dissociation energy of the reactants AB and H2O on V-doped catalysts were lower than those of Ru/Ti3C2, thus optimizing the catalytic kinetics of AB hydrolysis. The modification strategy of V-doped Ti3C2 provides a new pathway for the development of high-performance catalysts for AB hydrolysis.

Nitrogen-Anchored Boridene Enables Mg-CO2 Batteries with High Reversibility.

Nanoscale defect engineering plays a crucial role in incorporating extraordinary catalytic properties in two-dimensional materials by varying the surface groups or site interactions. Herein, we synthesized high-loaded nitrogen-doped Boridene (N-Boridene (Mo4/3(BnN1-n)2-mTz), N-doped concentration up to 26.78 at %) nanosheets by chemical exfoliation followed by cyanamide intercalation. Three different nitrogen sites are observed in N-Boridene, wherein the site of boron vacancy substitution mainly accounts for its high chemical activity. Attractively, as a cathode for Mg-CO2 batteries, it delivers a long-term lifetime (305 cycles), high-energy efficiency (93.6%), and ultralow overpotential (∼0.09 V) at a high current of 200 mA g-1, which overwhelms all Mg-CO2 batteries reported so far. Experimental and computational studies suggest that N-Boridene can remarkably change the adsorption energy of the reaction products and lower the energy barrier of the rate-determining step (*MgCO2 → *MgCO3·xH2O), resulting in the rapid reversible formation/decomposition of new MgCO3·5H2O products. The surging Boridene materials with defects provide substantial opportunities to develop other heterogeneous catalysts for efficient capture and converting of CO2.

N-Decorated Main-Group MgAl2O4 Spinel: Unlocking Exceptional Oxygen Reduction Activity for Zn-Air Batteries.

The development of economical and efficient oxygen reduction reaction (ORR) catalysts is crucial to accelerate the widespread application rhythm of aqueous rechargeable zinc-air batteries (ZABs). Here, a strategy is reported that the modification of the binding energy for reaction intermediates by the axial N-group converts the inactive spinel MgAl2O4 into the active motif of MgAl2O4-N. It is found that the introduction of N species can effectively optimize the electronic configuration of MgAl2O4, thereby significantly reducing the adsorption strength of *OH and boosting the reaction process. This main-group MgAl2O4-N catalyst exhibits a high ORR activity in a broad pH range from acidic and alkaline environments. The aqueous ZABs assembled with MgAl2O4-N shows a peak power density of 158.5 mW cm-2, the long-term cyclability over 2000 h and the high stability in the temperature range from -10 to 50 °C, outperforming the commercial Pt/C in terms of activity and stability. This work not only serves as a significant candidate for the robust ORR electrocatalysts of aqueous ZABs, but also paves a new route for the effective reutilization of waste Mg alloys.

Regulating d-Orbital Hybridization of Subgroup-IVB Single Atoms for Efficient Oxygen Reduction Reaction.

Highly active single-atom electrocatalysts for the oxygen reduction reaction are crucial for improving the energy conversion efficiency, but they suffer from a limited choice of metal centers and unsatisfactory stabilities. Here, this work reports that optimization of the binding energies for reaction intermediates by tuning the d-orbital hybridization with axial groups converts inactive subgroup-IVB (Ti, Zr, Hf) moieties (MN4) into active motifs (MN4O), as confirmed with theoretical calculations. The competition between metal-ligand covalency and metal-intermediate covalency affects the d-p orbital hybridization between the metal site and the intermediates, converting the metal centers into active sites. Subsequently, dispersed single-atom M sites coordinated by nitrogen/oxygen groups have been prepared on graphene (s-M-N/O-C) catalysts on a large-scale with high-energy milling and pyrolysis. Impressively, the s-Hf-N/O-C catalyst with 5.08 wt% Hf exhibits a half-wave potential of 0.920 V and encouraging performance in a zinc-air battery with an extraordinary cycling life of over 1600 h and a large peak power-density of 256.9 mW cm-2. This work provides promising single-atom electrocatalysts and principles for preparing other catalysts for the oxygen reduction reaction.

A Sodiophilic Amyloid Fibril Modified Separator for Dendrite-Free Sodium-Metal Batteries.

Sodium (Na) batteries are being considered as prospective candidates for the next generation of secondary batteries in contrast to lithium-based batteries, due to their high raw-material abundance, low cost, and sustainability. However, the unfavorable growth of Na-metal deposition and severe interfacial reactions have prevented their large-scale applications. Here, a vacuum filtration strategy, through amyloid-fibril-modified glass-fiber separators, is proposed to address these issues. The modified symmetric cell can be cycled for 1800 h, surpassing the performance of previously reported Na-based electrodes under an ester-based electrolyte. Moreover, the Na/Na3 V2 (PO4 )3 full cell with a sodiophilic amyloid-fibril-modified separator exhibits a capacity retention of 87.13% even after 1000 cycles. Both the experimental and the theoretical results show that the sodiophilic amyloid fibril homogenizes the electric field and Na-ion concentration, fundamentally inhibiting dendrite formation. Simultaneously, the glutamine amino acids in the amyloid fibril have the highest adsorption energy for Na, resulting in the formation of a stable Na3 N- and NaNx Oy -rich solid-electrolyte-interface film on the anode during cycling. This work provides not only a possible pathway to solve the dendrite problem in metal batteries using environmentally friendly biomacromolecular materials, but also a new direction for expanding biomaterial applications.

Construction of cellulose acetate-based composite nanofiber films with effective antibacterial and filtration properties.

In recent years, the safety of public health has attracted more and more attention. In order to avoid the spread of bacteria and reduce the diseases caused by their invasion of the human body, novel filtration and antibacterial materials have attracted more and more attention. In this work, the antibacterial agents silver nanoparticles (AgNPs) and cetylpyridine bromide (CPB) were introduced into a cellulose acetate (CA) nanofiber film by electrospinning technology to prepare CA-based composite films with good antibacterial and filtration properties. The results of the antibacterial test of the composite nanofiber films showed that AgNPs and CPB had synergistic antibacterial effects and exhibited good antibacterial properties against a variety of bacteria. In addition, in vitro cytotoxicity, skin irritation and skin sensitization experiments proved that the CA/AgNPs, CA/CPB and CA/CPB/AgNPs films produced no skin irritation or sensitization in the short term. These are expected to become potential materials for the preparation of new antibacterial masks. This work provides a new idea for developing materials with good antibacterial properties for enhancing protection via filtration masks.

Reversible Insertion of [AlCl4 ]- Superhalides in Graphite.

Graphite-based dual-ion batteries are with potential higher energy density, making them a unique candidate in energy storage systems. However, anion insertion into graphite in aqueous environment remains a significant challenge. Herein, we report that the reversible insertion of Al-Cl superhalide into expanded graphite (EG) delivers an ultrahigh specific capacity of ~171 mAh g-1 from an aqueous deep eutectic solvent (DES) gel electrolyte of 50 m ChCl+5 m AlCl3 . High-resolution transmission electron microscopy (HRTEM), Raman spectra and X-ray diffraction (XRD) show that the EG generates turbostratic structure during Al-Cl superhalide (de)insertion instead of presenting typical graphite intercalation compounds (GIC), thus attributing to the high capacity during Al-Cl superhalide insertion.

Pathogenic Rickettsia, Anaplasma, and Ehrlichia in Rhipicephalus microplus ticks collected from cattle and laboratory hatched tick larvae.

BACKGROUND: The order Rickettsiales contains a group of vector-borne gram-negative obligate intracellular bacteria, which often cause human emerging infectious diseases and economic losses for dairy and meat industries. The purpose of this study is to investigate the distribution of the pathogens including Rickettsia spp., Anaplasma spp., and Ehrlichia spp. in the order Rickettsiales in ticks from Yueyang, a prefecture-level city of Hunan Province in Sothern China, and assess the potentiality of transovarial transmission of these rickettsial organisms. METHODS: Ticks were collected from cattle in a farm in Yueyang City and the tick DNA was used as template to amplify the htrA, rrs, gltA, ompA and ompB genes of Rickettsia as well as rrs and groEL genes of Anaplasma and Ehrlichia. RESULTS: All ticks (465) collected were the cattle tick, Rhipicephalus microplus. PCR showed the minimum infection rate (MIR) was 1.5% (7/465) for Candidatus Rickettsia xinyangensis, 1.9% (9/465) for C. Anaplasma boleense, 1.3% (6/465) for Anaplasma platys, 0.6% (3/465) for A. marginale, and 1.17% (2/465) for each of A. bovis, Ehrlichia minasensis, and a non-classified Ehrlichia sp. A human pathogen, C. Rickettsia xinyangensis and A. platys were detected in 100% (3/3) and 33.3% (2/6) laboratory-hatched larval pools from infected females respectively. CONCLUSION: Our study revealed a diversity of pathogenic rickettsial species in R. microplus ticks from Hunan Province suggesting a threat to people and animals in China. This study also provided the first molecular evidence for the potential transovarial transmission of C. Rickettsia xinyangensis and A. platys in R. microplus, indicating that R. microplus may act as the host of these two pathogens.

High prevalence and genetic diversity of hemoplasmas in bats and bat ectoparasites from China.

Hemoplasmas can cause severe hemolytic anemia in humans. To explore the genetic diversity and the potential transmission routes of hemoplasmas among bat population, bats and bat-ectoparasites including bat-flies, bat-mites, and bat-ticks were collected in Eastern and Central China from 2015 to 2021, and tested with PCR for hemoplasmas 16S rRNA gene. Based on 16S rRNA PCR, 18.0% (103/572) adult bats were positive for hemoplasmas, but none of 11 fetuses from hemoplasmas-positive pregnant bats was positive for hemoplasmas. These results indicated that adult bats had a high prevalence of hemoplasma, but vertical transmission of hemoplasmas did not occurr in the bats. Based on the 16S rRNA gene PCR, the minimum infection rate of bat-ectoparasite for hemoplasmas was 4.0% (27/676), suggesting that bat-ectoparasite also had a high prevalence for hemoplasmas. Phylogenetic analysis revealed that bat hemoplasmas from this study clustered into 4 genotypes (I-IV). Genotype I clustered together with hemoplasmas identified in bats from America. Genotype II shared high similarity with a human-pathogenic hemoplasma Candidatus Mycoplasma haemohominis. Genotype III and IV were unique, representing 2 new hemoplasma genotypes. Only genotype I was identified in both bats and all bat-ectoparasites including bat-flies, bat-mites, and bat-ticks. In conclusion, bats and bat-ectoparasites from China harbored abundant genetically diverse hemoplasmas including potential human-pathogenic hemoplasmas, indicating bats and bat-ectoparasites may play important roles in the maintenance and transmission of hemoplasmas in the natural foci.

Host specificity and genetic diversity of Bartonella in rodents and shrews from Eastern China.

Bartonella are vector-borne gram-negative facultative intracellular bacteria causing emerging infectious diseases worldwide, and two thirds of known Bartonella species are carried by rodents. We captured rodents, shrews and rodent ectoparasitic mites in rural areas of Qingdao City, Shandong Province, China from 2012 to 2021 and used the animal spleen tissues for the PCR amplification of Bartonella gltA and rpoB genes. PCR showed 9.4% (40/425) rodents, and 5.1% (12/235) shrews were positive for Bartonella. Seven Bartonella species including three novel species were identified in five rodent species and one shrew species, indicating the abundance and genetic diversity of Bartonella in rodents and shrews. The infection rate of each Bartonella species in the animal species was as below: novel Candidatus Bartonella crocidura in shrews Crocidura lasiura (5.1%, 12/235); novel Candidatus Bartonella cricetuli in hamsters Tscherskia triton (20%, 9/45); novel Candidatus Bartonella muris in striped field mice Apodemus agrarius (4.2%, 7/168) and house mice Mus musculus (1.5%, 2/135); Bartonella fuyuanensis in striped field mice (8.9%, 15/168) and house mice (0.7%, 1/135); Bartonella rattimassiliensis and Bartonella tribocorum in brown rats Rattus norvegicus (6.7%, 3/45 and 4.2%, 2/45, respectively); Bartonella queenslandensis in Chinese white-bellied rat Niviventer confucianus (12.5%, 1/8). These results suggest that Bartonella infected a variety of rodent and shrew species with high infection rate, but each Bartonella specie is restricted to infect only one or a few genetically closely related rodent species. In addition, Candidatus Bartonella cricetuli, Candidatus Bartonella muris and Bartonella coopersplainsensis were found in chigger Walchia micropelta (33.3%, 3/9), and B. fuyuanensis were found in chigger Leptotrombidium intermedium (4.1%, 1/24), indicating chiggers may be reservoirs of Bartonella. In conclusion, abundant genetic diversified Bartonella species are found to infect rodents, shrews and chiggers, but each Bartonella species has a strict rodent animal host specificity; and chigger mites may play a role in Bartonella transmission.

Natural Mediterranean Spotted Fever Foci, Qingdao, China.

We sequenced DNA from spleens of rodents captured in rural areas of Qingdao, East China, during 2013-2015. We found 1 Apodemus agrarius mouse infected with Rickettsia conorii, indicating a natural Mediterranean spotted fever foci exists in East China and that the range of R. conorii could be expanding.

SFTSV infection in rodents and their ectoparasitic chiggers.

SFTSV, a tick-borne bunyavirus causing a severe hemorrhagic fever termed as severe fever with thrombocytopenia syndrome (SFTS). To evaluate the potential role of rodents and its ectoparasitic chiggers in the transmission of SFTSV, we collected wild rodents and chiggers on their bodies from a rural area in Qingdao City, Shandong Province, China in September 2020. PCR amplification of the M and L segments of SFTSV showed that 32.3% (10/31) of rodents and 0.2% (1/564) of chiggers (Leptotrombidium deliense) from the rodents were positive to SFTSV. Our results suggested that rodents and chiggers may play an important role in the transmission of SFTSV, although the efficiency of chiggers to transmit SFTSV needs to be further investigated experimentally.

An aqueous copper battery enabled by Cu2+/Cu+ and Cu3+/Cu2+ redox conversion chemistry.

We propose an aqueous copper battery via Cu2+/Cu+ and Cu3+/Cu2+ redox conversion chemistry on an activated carbon (AC) electrode enabled by a 30 m ChCl + 1 m CuCl2 electrolyte, where Cu3+/Cu2+ redox promotes the discharge capacity by ∼50 mA h g-1 at ∼1.0 V vs. Ag/AgCl with stable cycling.

Bats and their ectoparasites (Nycteribiidae and Spinturnicidae) carry diverse novel Bartonella genotypes, China.

Bartonella species are facultative intracellular bacteria and recognized worldwide as emerging zoonotic pathogens. Bartonella were isolated or identified by polymerase chain reaction (PCR) in bats and their ectoparasites worldwide, whereas the association between them was scarce, especially in Asia. In this study, a retrospective analysis with frozen samples was carried out to identify the genetic diversity of Bartonella in bats and their ectoparasites and to investigate the relationships of Bartonella carried by bats and their ectoparasites. Bats and their ectoparasites (bat flies and bat mites) were collected from caves in Hubei Province, Central China, from May 2018 to July 2020. Bartonella were screened by PCR amplification and sequencing of three genes (gltA, rpoB, and ftsZ). Bats, bat flies, and bat mites carried diverse novel Bartonella genotypes with a high prevalence. The sharing of some Bartonella genotypes between bats and bat flies or bat mites indicated a potential role of bat flies and bat mites as vectors of bartonellae, while the higher genetic diversity of Bartonella in bat flies than that in bats might be due to the vertical transmission of this bacterium in bat flies. Therefore, bat flies might also act as reservoirs of Bartonella. In addition, human-pathogenic B. mayotimonesis was identified in both bats and their ectoparasites, which expanded our knowledge on the geographic distribution of this bacterium and suggested a potential bat origin with bat flies and bat mites playing important roles in the maintenance and transmission of Bartonella.

Efficient and sustainable phosphate removal from water by small-sized Al(OH)3 nanocrystals confined in discarded Artemia Cyst-shell: Ultrahigh sorption capacity and rapid sequestration.

We reported a new strategy for efficient phosphate removal from wastewaters, it relies on the discarded Artemia Cyst-shell in-situ growth of Al(OH)3 nanocluster, the charged amino-acids components of skeleton make available for the small size of Al(OH)3 formation (< 10 nm) with high activity, and the three-dimensional porous structure of discarded matrix provides fast kinetics and efficient Al(OH)3 nanoparticles utilization. These hybrid adsorbents exhibit ultrahigh capacity (850.5 mg/g) and fast kinetics (~2 min) by recent ten-years (2011-2020) survey, the superior selectivity against various foreign ions, with a distribution coefficient (Kd) as high as 4820 mL/g, the porous structure and fast kinetics also accelerate the phosphate accessibility, yielding a satisfactory capacity of ~3000 L/kg sorbent (Artemia CS-Al) for the application, even varying at high feeding-speeds. The saturated adsorbent can be readily regenerated and reused without decrease in performance, this technology is promising for mitigating the contamination problem of excess phosphate worldwide.

New insight into the bioinspired sub-10 nm Sn(HPO4)2 confinement for efficient heavy metal remediation in wastewater.

Heavy metal pollution poses a severe threat to the water environment. Engineering sub-10 nm active functional materials is an important approach to address the problems, and nanocomposites, developed in recent years by pore confinement always present weaken diffusion and low utilization of nanoparticles. In this study, we successfully prepared the polydopamine confined high-density sub-10 nm Sn(HPO4)2 coating for toxic lead(II) removal and its unique external coating structure and superior active sub-10 nm size achieved remarkable performances for heavy metal remediation. The hybrid sub-10 nm coating exhibits an extended acidic environment application (pH = 2.0-7.0) as well as significant selectivity with a superior Kd values (9.4 × 104 mL/g, which is 450 times greater than that of commercial sulfonated polystyrene. Ultrafast filtrations by vacuum further validate its superior sequestration (near to 100%) to Pb and Cd ions at different concentrations (10-100 mg/L) for 2 mins. The real column application further demonstrates the remarkable capacity of 11800 kg/kg sorbents, the trace effluents with three orders (∼103) reduction to below 1 ppb (> 99.9% Pb removal) and efficient stability for several cycles. The effective performances are mainly driven by the PDA motivated external nanoparticles arrangement and strong inner-sphere complexation by small size of Sn(HPO4)2. These results set a new benchmark for removing toxic metals and the proposed approach (engineering sub-10 nm coating design) is unique for heavy metal removal.

Self-Assembled Sandwich-like MXene-Derived Composites as Highly Efficient and Sustainable Catalysts for Wastewater Treatment.

Photocatalysts play an increasingly important role in environmental remediation polluted by industrial wastewater. However, the preparation of adsorbents and catalysts with high activity by simple and easy methods is still a great challenge. Here, sandwich-like composite catalyst Cu2O/TiO2/Ti3C2 was prepared by an easily available solvent reduction measure for the highly efficient catalytic nitro compounds. In particular, sandwich-like composite catalyst Cu2O/TiO2/Ti3C2 exhibits excellent catalysis for 2-nitroaniline (2-NA) and 4-nitrophenol (4-NP), and its pseudo-first-order reaction rate constants (k) are 0.163 and 0.114 min-1, respectively. Interestingly, even after eight consecutive cycles of catalytic experiments, the conversion rates of catalytic 2-NA and 4-NP are still greater than 95 and 92%, respectively, demonstrating that the obtained catalyst has excellent catalytic capability and a high reutilization rate. The excellent catalytic performances of Cu2O/TiO2/Ti3C2 can be attributed to the fact that Ti3C2 provides a greater reaction site for the formation of Cu2O and reduces the aggregation during the formation of Cu2O by in situ synthesis. Therefore, ternary composite catalyst Cu2O/TiO2/Ti3C2 prepared by solvent reduction not only supplies a technical method for the catalytic reaction of MXene-based material but also lays the foundation for the development of new photocatalysts.

A Lactoglobulin-Composite Self-Healing Coating for Mg Alloys.

Corrosion issue is one of the most crucial bottlenecks for extensive employment of Mg alloys, in particular under harsh engineering conditions. Differing from traditional approaches, a self-healing protective coating composed of lactoglobulin is proposed herein to offer sustainable protection to the underlying Mg parts. Corrosion resistance, evaluated by electrochemical measurements and hydrogen evolution tests, indicates that the lactoglobulin composite film exhibits nobler corrosion potential (-1.28 VSCE), smaller corrosion current density (8.4 × 10-6 A/cm2), and lower average corrosion rate (∼0.03 mm/y) than those of its bare counterparts. Moreover, the pre-made cracks in the film were evidently self-healed within 24 h of exposure to corrosive media. The proposed self-healing lactoglobulin composite film provides opportunities to tackle the corrosion challenges of Mg alloys.

In Situ Electrochemical Study of Na-O2/CO2 Batteries in an Environmental Transmission Electron Microscope.

Metal-air batteries are potential candidates for post-lithium energy storage devices due to their high theoretical energy densities. However, our understanding of the electrochemistry of metal-air batteries is still in its infancy. Herein we report in situ studies of Na-O2/CO2 (O2 and CO2 mixture) and Na-O2 batteries with either carbon nanotubes (CNTs) or Ag nanowires as the air cathode medium in an advanced aberration corrected environmental transmission electron microscope. In the Na-O2/CO2-CNT nanobattery, the discharge reactions occurred in two steps: (1) 2Na+ + 2e- + O2 → Na2O2; (2) Na2O2+ CO2 → Na2CO3 + O2; concurrently a parasitic Na plating reaction took place. The charge reaction proceeded via (3) 2Na2CO3 + C → 4Na+ + 3CO2 + 4e-. In the Na-O2/CO2-Ag nanobattery, the discharge reactions were essentially the same as those for the Na-O2/CO2-CNT nanobattery; however, the charge reaction in the former was very sluggish, suggesting that direct decomposition of Na2CO3 is difficult. In the Na-O2 battery, the discharge reaction occurred via reaction 1, but the reverse reaction was very difficult, indicating the sluggish decomposition of Na2O2. Overall the Na-O2/CO2-CNT nanobattery exhibited much better cyclability and performance than the Na-O2/CO2-Ag and the Na-O2-CNT nanobatteries, underscoring the importance of carbon and CO2 in facilitating the Na-O2 nanobatteries. Our study provides important understanding of the electrochemistry of the Na-O2/CO2 and Na-O2 nanobatteries, which may aid the development of high performance Na-O2/CO2 and Na-O2 batteries for energy storage applications.

Facile Synthesis of Self-Assembled NiFe Layered Double Hydroxide-Based Azobenzene Composite Films with Photoisomerization and Chemical Gas Sensor Performances.

Two kinds of layered double hydroxide (LDH) Langmuir composite films containing azobenzene (Azo) groups were successfully prepared by Langmuir-Blodgett (LB) technology. Then, an X-ray diffractometer (XRD), a transmission electron microscope (TEM), and an atomic force microscope (AFM) were used to investigate the structures of NiFe-LDH and the uniform morphologies of the composite LB films. The photoisomerization and acid-base gas sensor performances of the obtained thin film samples were tested by infrared visible (FTIR) spectroscropy and ultraviolet visible (UV-vis) spectroscropy. It is proved that the Azo dye molecules in the composite film are relatively stable to photoisomerization. In addition, the prepared composite films have high sensing sensitivity and good recyclability for acid-base response gases. The present research proposes a new clue for designing thin film materials for chemical gas response with good stability and sensitivity.