The design and engineering strategies of metal tellurides for advanced metal-ion batteries

Owning various crystal structures and high theoretical capacity,metal tellurides are emerging as promising electrode materials for high-performance metal-ion batteries(MBs).Since metal telluride-based MBs are quite new,fundamental issues raise regarding the energy storage mechanism and other aspects affecting electrochemical performance.Severe volume expansion,low intrinsic conductivity and slow ion diffusion kinetics jeopardize the performance of metal tellurides,so that rational design and engineering are crucial to circumvent these disadvantages.Herein,this review provides an in-depth discussion of recent investigations and progresses of metal tellurides,beginning with a critical discussion on the energy storage mechanisms of metal tellurides in various MBs.In the following,recent design and engineering strategies of metal tellurides,including morphology engineering,compositing,defect engineering and heterostructure construction,for high-performance MBs are summarized.The primary focus is to present a comprehensive understanding of the structural evolution based on the mechanism and corresponding effects of dimension control,composition,electron configuration and structural complexity on the electrochemical performance.In closing,outlooks and prospects for future development of metal tellurides are proposed.This work also highlights the promising directions of design and engineering strategies of metal tellurides with high performance and low cost.

Tensile Properties of Mechanically-Defibrated Cellulose Nanofiber-Reinforced Polylactic Acid Matrix Composites Fabricated by Fused Deposition Modeling

Biodegradable polymers are highly attractive as potential alternatives to petroleum-based polymers in an attempt to achieve carbon neutrality whilst maintaining the mechanical properties of the structures.Among these polymers,polylactic acid(PLA)is particularly promising due to its good mechanical properties,biocompatibility and thermoplasticity.In this work,we aim to enhance the mechanical properties of PLA using mechanically-defibrated cellulose nanofibers(CNFs)that exhibit remarkable mechanical properties and biodegradability.We also employ fused deposition modeling(FDM),one of the three-dimensional printing methods for thermoplastic polymers,for the low-cost fabrication of the products.Mechanically-defibrated CNF-reinforced PLA matrix composites are fabricated by FDM.Their tensile properties are investigated in two printing directions(0°/90°and+45°/-45°).The discussion about the relationship between printing direction and tensile behavoir of mechanically-defibrated CNF-reinforced PLA matrix composite is the unique point of this study.We further discuss the microstructure and fracture surface of mechanically-defibrated CNF-reinforced PLA matrix composite by scanning electron microscope.

Ultrasmall AuPd nanoclusters on amine-functionalized carbon blacks as high-performance bi-functional catalysts for ethanol electrooxidation and formic acid dehydrogenation

The synthesis of ultrasmall metal nanoclusters(NCs) with high catalytic activities is of great importance for the development of clean and renewable energy technologies but remains a challenge. Here we report a facile wet-chemical method to prepare ~1.0 nm Au Pd NCs supported on amine-functionalized carbon blacks. The Au Pd NCs exhibit a specific activity of 5.98 mA cm_(AuPd)^(-2)and mass activity of 5.25 A mg_(auPd)^(-1) for ethanol electrooxidation, which are far better than those of commercial Pd/C catalysts(1.74 mAcm_(AuPd)^(-2) and 0.54 A mg_(Pd)^(-1) ). For formic acid dehydrogenation, the Au Pd NCs have an initial turn over frequency of 49339 h^(-1) at 298 K without any additive, which is much higher than those obtained for most of reported Au Pd catalysts. The reported synthesis may represent a facile and low-cost approach to prepare other ultrasmall metal NCs with high catalytic activities for various applications.

Blocking backward reaction on hydrogen evolution cocatalyst in a photosystem Ⅱ hybrid Z-scheme water splitting system

Photocatalytic Z-scheme water splitting is considered as a promising approach to produce solar hydrogen.However,the forward hydrogen production reaction is often impeded by backward reactions.In the present study,in a photosystem Ⅱ-integrated hybrid Z-scheme water splitting system,the backward hydrogen oxidation reaction was significantly suppressed by loading a PtCrOx cocatalyst on a ZrO2/TaON photocatalyst.Due to the weak chemisorption and activation of molecular hydrogen on PtCrOx,where Pt is stabilized in the oxidized forms,Pt^Ⅱ and Pt^Ⅳ,hydrogen oxidation is inhibited.However,it is remarkably well-catalyzed by the metallic Pt cocatalyst,thereby rapidly consuming the produced hydrogen.This work describes an approach to inhibit the backward reaction in the photosystem Ⅱ-integrated hybrid Z-scheme water splitting system using Fe(CN)6^3-/Fe(CN)6^4-redox couple as an electron shuttle.

Avalonia,get bent!–Paleomagnetism from SW Iberia confirms the Greater Cantabrian Orocline

The amalgamation of Pangea formed the contorted Variscan-Alleghanian orogen,suturing Gondwana and Laurussia during the Carboniferous.From all swirls of this orogen,a double curve in Iberia stands out,the coupled Cantabrian Orocline and Central Iberian curve.The Cantabrian Orocline formed at ca.315–290 Ma subsequent to the Variscan orogeny.The formation mechanism of the Cantabrian Orocline is disputed,the most commonly proposed mechanisms include either(1)that south-westernmost Iberia would be an Avalonian(Laurussian)indenter or(2)that the stress field changed,buckling the orogen.In contrast,the geometry and kinematics of the Central Iberian curve are largely unknown.Whereas some authors defend both curvatures are genetically linked,others support they are distinct and formed at different times.Such uncertainty adds an extra layer of complexity to our understanding of the final stages of Pangea’s amalgamation.To solve these issues,we study the late Carboniferous–early Permian vertical-axis rotations of SW Iberia with paleomagnetism.Our results show up to 70counterclockwise vertical-axis rotations during late Carboniferous times,concurring with the anticipated kinematics if SW Iberia was part of the southern limb of the Cantabrian Orocline.Our results do not allow the necessary penecontemporaneous clockwise rotations in Central Iberia to support a concomitant formation of both Cantabrian and Central Iberian curvature.The coherent rotation of both Gondwanan and Avalonian pieces of SW Iberia discards the Laurussian indenter hypothesis as a formation mechanism of the Cantabrian Orocline and confirms the Greater Cantabrian Orocline hypothesis.The Greater Cantabrian Orocline likely formed as a consequence of a change in the stress field during the late Carboniferous and extended beyond the Rheic Ocean suture affecting the margins of both Laurussia and Gondwana.

Twisted fiber microfluidics:a cutting-edge approach to 3D spiral devices

The development of 3D spiral microfluidics has opened new avenues for leveraging inertial focusing to analyze small fluid volumes,thereby advancing research across chemical,physical,and biological disciplines.While traditional straight microchannels rely solely on inertial lift forces,the novel spiral geometry generates Dean drag forces,eliminating the necessity for external fields in fluid manipulation.Nevertheless,fabricating 3D spiral microfluidics remains a labor-intensive and costly endeavor,hindering its widespread adoption.Moreover,conventional lithographic methods primarily yield 2D planar devices,thereby limiting the selection of materials and geometrical configurations.To address these challenges,this work introduces a streamlined fabrication method for 3D spiral microfluidic devices,employing rotational force within a miniaturized thermal drawing process,termed as mini-rTDP.This innovation allows for rapid prototyping of twisted fiber-based microfluidics featuring versatility in material selection and heightened geometric intricacy.To validate the performance of these devices,we combined computational modeling with microtomographic particle image velocimetry(uTPiM)to comprehensively characterize the 3D flow dynamics.Our results corroborate the presence of a steady secondary flow,underscoring the effectiveness of our approach.Our 3D spiral microfluidics platform paves the way for exploring intricate microflow dynamics,with promising applications in areas such as drug delivery,diagnostics,and lab-on-a-chip systems.

3D Nanoporous Graphene Based Single-Atom Electrocatalysts for Energy Conversion and Storage

CONSPECTUS:This Account will provide an overview and analysis on recent research of 3D nanoporous graphene based single-atom electrocatalysts for energy conversion and storage applications.In order to meet the increasing energy demands and assist in the transition from a global economy that relies heavily on fossil fuels to one that utilizes more renewable energy sources,there is urgent need to develop highperforming electrocatalysts toward renewable energy related reactions.These catalysts are expected to have low overpotentials,high reaction selectivity,long cycling stability,and,importantly,lower materials costs to address the challenges of traditional nanoparticulate noble metal catalysts.

Cryo-electron microscopy structure of the intact photosynthetic light-harvesting antenna-reaction center complex from a green sulfur bacterium

The photosynthetic reaction center complex(RCC)of green sulfur bacteria(GSB)consists of the membrane-imbedded RC core and the peripheric energy transmitting proteins called Fenna–Matthews–Olson(FMO).Functionally,FMO transfers the absorbed energy from a huge peripheral light-harvesting antenna named chlorosome to the RC core where charge separation occurs.In vivo,one RC was found to bind two FMOs,however,the intact structure of RCC as well as the energy transfer mechanism within RCC remain to be clarified.Here we report a structure of intact RCC which contains a RC core and two FMO trimers from a thermophilic green sulfur bacterium Chlorobaculum tepidum at 2.9A resolution by cryo-electron microscopy.The second FMO trimer is attached at the cytoplasmic side asymmetrically relative to the first FMO trimer reported previously.We also observed two new subunits(PscE and PscF)and the N-terminal transmembrane domain of a cytochrome-containing subunit(PscC)in the structure.These two novel subunits possibly function to facilitate the binding of FMOs to RC core and to stabilize the whole complex.A new bacteriochlorophyll(numbered as 816)was identified at the interspace between PscF and PscA-1,causing an asymmetrical energy transfer from the two FMO trimers to RC core.Based on the structure,we propose an energy transfer network within this photosynthetic apparatus.

Functional Accumulation of Antenna Proteins in Chlorophyll b-Less Mutants of Chlamydomonas reinhardtii

The green alga Chlamydomonas reinhardtii contains several light-harvesting chlorophyll a/b complexes （LHC）- four major LHCIIs, two minor LHClIs, and nine LHCIs. We characterized three chlorophyll b-less mutants to assess the effect of chlorophyll b deficiency on the function, assembly, and stability of these chlorophyll a/b binding proteins. We identified point mutations in two mutants that inactivate the CAO gene responsible for chlorophyll a to chlorophyll b conversion. All LHClIs accumulated to wild-type levels in a CAO mutant but their light-harvesting function for photosystem II was impaired. In contrast, most LHCIs accumulated to wild-type levels in the mutant and their light-harvesting capability for photosystem I remained unaltered. Unexpectedly, LHCl accumulation and the photosystem I functional antenna size increased in the mutant compared with in the wild type when grown in dim light. When the CAO mutation was placed in a yellow-in-the-dark background （yid-BF3）, in which chlorophyll a synthesis remains limited in dim light, accumulation of the major LHClIs and of most LHCls was markedly reduced, indicating that sustained synthesis of chlorophyll a is required to preserve the proteolytic resistance of antenna pro- teins. Indeed, after crossing yid-BF3 with a mutant defective for the thylakoid FtsH protease activity, yid- BF3-ftshl restored wild-type levels of LHCI, which defines LHCI as a new substrate for the FtsH protease.

Elucidating the Molecular Mechanism of Dynamic Photodamage of Photosystem II Membrane Protein Complex by Integrated Proteomics Strategy

Photosystem II(PSII),as a multiple-subunit chloroplast membrane-associated pigment-protein complex on the thylakoid membrane,is a primary target of light-induced photodamage.However,the overall molecular details of the conformation and composition dynamics of PSII photodamage are still controversial.In this study,we investigated systematically the dynamic conformation,degradation,and oxidation processes of PSII photodamage by integrating chemical cross-linking and top-down proteomics strategies.

Phase diagram of a distorted kagome antiferromagnet and application to Y-kapellasite

We investigate the magnetism of a previously unexplored distorted spin-1/2 kagome model consisting of three symmetry-inequivalent nearest-neighbor antiferromagnetic Heisenberg couplings J_(■),J,and J′,and uncover a rich ground state phase diagram even at the classical level.Using analytical arguments and numerical techniques we identify a collinear Q^(→)=0 magnetic phase,two unusual non-collinear coplanar Q^(→)=(1/3,1/3)phases and a classical spin liquid phase with a degenerate manifold of non-coplanar ground states,resembling the jammed spin liquid phase found in the context of a bond-disordered kagome antiferromagnet.We further show with density functional theory calculations that the recently synthesized Y-kapellasite Y_(3)Cu_(9)(OH)_(19)C_(l8) is a realization of this model and predict its ground state to lie in the region of Q^(→)=(1/3,1/3)order,which remains stable even after the inclusion of quantum fluctuation effects within variational Monte Carlo and pseudofermion functional renormalization group.The presented model opens a new direction in the study of kagome antiferromagnets.