Recent advances in engineered nanomaterials for acute kidney injury theranostics

Acute kidney injury(AKI),has become the focus of increasing attention due to its high risk of death.The early diagnosis and treatment of AKI significantly reduce the risk of renal tissue damage and kidney dysfunction.However,the efficient early diagnosis and treatment approach for AKI remains a challenge.AKI screening via precise nanomaterial theranostics is a new alternative approach.This study summarizes the recent advances in functional nanomaterials in the early detection and treatment of AKI.The challenges and problems in the use of nanomaterials for AKI in clinical applications are also discussed.It is anticipated that highlighting these new advances will lay the foundation for further translational research on the promising application of nanomaterials for AKI.     

Two-dimensional polymer nanosheets for efficient energy storage and conversion

As a promising graphene analogue, two-dimensional (2D) polymer nanosheets with unique 2D features, diversified topological structures and as well as tunable electronic properties, have received extensive attention in recent years. Here in this review, we summarized the recent research progress in the preparation methods of 2D polymer nanosheets, mainly including interfacial polymerization and solution polymerization. We also discussed the recent research advancements of 2D polymer nanosheets in the fields of energy storage and conversion applications, such as batteries, supercapacitors, electrocatalysis and photocatalysis. Finally, on the basis of their current development, we put forward the existing challenges and some personal perspectives.

     

Rapid room-temperature synthesis of a porphyrinic MOF for encapsulating metal nanoparticles

While metal nanoparticles(NPs)have shown great promising applications as heterogeneous catalysts,their agglomeration caused by thermodynamic instability is detrimental to the catalytic performance.To tackle this hurdle,we successfully prepared a functional and stable porphyrinic metal-organic framework(MOF),PCN-224-RT,as a host for encapsulating metal nanoparticles by direct stirring at room temperature.As a result,Pt@PCN-224-RT composites with well-dispersed Pt NPs can be constructed by introducing pre-synthesized Pt NPs into the precursor solution of PCN-224-RT.Of note,the rapid and simple stirring method in this work is more in line with the requirements of environmental friendly and industrialization compared with traditional solvothermal methods.     

Ambipolar two-dimensional bismuth nanostructures in junction with bismuth oxychloride

Despite the unique properties of bismuth(Bi),there is a lack of two-dimensional(2D)heterostructures between Bi and other functional 2D materials.Here,a coherent strategy is reported to simultaneously synthesize rhombohedral phase Bi nanoflakes and bismuth oxychloride(BiOCI)nanosheets.The delicate balance between several reactions is mediated mainly for the reduction and chlorination in the chemical vapor transport(CVT)process.The Bi-BiOCI lateral heterostructures have been constructed via the coalescence of the two different 2D nanostructures.The characteristics of ambipolar conducting Bi and insulator-like BiOCI are elaborated by scanning microwave impedance microscopy(sMIM).This work demonstrates a way to construct a 2D Bi nanostructure in junction with its oxyhalide.     

Layer-by-layer assembled dual-ligand conductive MOF nano-films with modulated chemiresistive sensitivity and selectivity

In this paper,a dual-ligand design strategy is demonstrated to modulate the performance of the electronically conductive metalorganic frameworks(EC-MOFs)thin film with a spray layer-by-layer assembly method.The thin film not only can be precisely prepared in nanometer scale(20-70 nm),but also shows the pin-hole-free smooth surface.The high quality nano-film of 2,3,6,7,10,11-hexaiminotriphenylene(HITP)doped Cu-HHTP enables the precise modulation of the chemiresistive sensitivity and selectivity.Selectivity improvement over 220%were realized for benzene vs.NH3>as well as enhanced response and recovery properties.In addition,the selectivity of the EC-MOF thin film sensors toward other gases(e.g.triethylamine,methane,ethylbenzene,hydrogen,butanone,and acetone)vs.NH3 at room temperature is also discussed.     

Discovery of Zr-based metal-organic polygon: Unveiling new design opportunities in reticular chemistry

Metal-based secondary building unit and the shape of organic ligands are the two crucial factors for determining the final topology of metal-organic materials.A careful choice of organic and inorganic structural building units occasionally produces unexpected structures,facilitating deeper fundamental understanding of coordination-driven self-assembly behind metal-organic materials.Here,we have synthesized a triangular metal-organic polygon(MOT-1),assembled from bulky tetramethyl terephthalate and Zr-based secondary building unit.Surprisingly,the Zr-based secondary building unit serves as an unusual ditopic Zr-connector,toform metal-organic polygon MOT-1,proven to be a good candidate for water adsorption with recyclability.This study highlights the interplay of the geometrically frustrated ligand and secondary building unit in controlling the connectivity of metal-organic polygon.Such a strategy can be further used to unveil a new class of metal-organic materials.     

How defects influence the photoluminescence of TMDCs

Two-dimensional(2D)transition metal dichalcogenide(TMDC)monolayers,a class of ultrathin materials with a direct bandgap and high exciton binding energies,provide an ideal platform to study the photoluminescence(PL)of light-emitting devices.Atomically thin TMDCs usually contain various defects,which enrich the lattice structure and give rise to many intriguing properties.As the influences of defects can be either detrimental or beneficial,a comprehensive understanding of the internal mechanisms underlying defect behaviour is required for PL tailoring.Herein,recent advances in the defect influences on PL emission are summarized and discussed.Fundamental mechanisms are the focus of this review,such as radiative/nonradiative recombination kinetics and band structure modification.Both challenges and opportunities are present in the field of defect manipulation,and the exploration of mechanisms is expected tofacilitate the applications of 2D TMDCs in the future.     

Highly efficient multi-metal catalysts for carbon dioxide reduction prepared from atomically sequenced metal organic frameworks

The precise control on the combination of multiple metal atoms in the structure of metal-organic frameworks(MOFs)endowed by reticular chemistry,allows the obtaining of materials with compositions that are programmed for achieving enhanced reactivity.The present work illustrates how through the transformation of MOFs with desired arrangements of metal cations,multi-metal spinel oxides with precise compositions can be obtained,and used as catalyst precursor for the reverse water-gas shift reaction.The differences in the spinel initial composition and structure,determined by neutron powder diffraction,influence the overall catalytic activity with changes in the process of in s itu formation of active,metal-oxide supported metal nanoparticles,which have been monitored and characterized with in situ X-ray diffraction and photoelectron spectroscopy studies.     

Nanovilli electrode boosts hydrogen evolution: A surface with superaerophobicity and superhydrophilicity

Although tremendous efforts have been paid on electrocatalysts toward efficient electrochemical hydrogen generation,breakthrough is still highly needed in the design and synthesis of wonderful non-precious-metal electrocatalyst.Herein,a nanovilli Ni2P electrode,which with superaerophobic and superhydropholic can significantly facilitate the mass and electron transfer was constructed via a facial morphology control strategy.Meanwhile,the substitution of sluggish oxygen evolution with urea oxidation,lowering the two-electrode cell voltage to only 1.48 volts to achieve a current density of 10 mA·cm^-2.Thus,the as-constructed electrode achieves the operation of hydrogen generation by an AA battery.This work sheds new light on the exploration of other high-efficient electrocatalysts for hydrogen generation by using intermittent clean energy.     

Coarse and fine-tuning of lasing transverse electromagnetic modes in coupled all-inorganic perovskite quantum dots

Inorganic perovskite lasers are of particular interest,with much recent work focusing on Fabry-P6rot cavity-forming nanowires.We demonstrate the direct observation of lasing from transverse electromagnetic(TEM)modes with a long coherence time-9.5ps in coupled CsPbBr₃ quantum dots,which dispense with an external cavity resonator and show how the wavelength of the modes can be controlled via two independent tuning-mechanisms.Controlling the pump power allowed us tofine-tune the TEM mode structure to the emission wavelength,thus providing a degree of control over the properties of the lasing signal.The temperature-tuning provided an additional degree of control over the wavelength of the lasing peak,importantly,maintained a constant full width at half maximum(FWHM)over the entire tuning range without mode-hopping.     

Recent progress about 2D metal dichalcogenides: Synthesis and application in photodetectors

In recent years, two-dimensional (2D) layered metal dichalcogenides (MDCs) have received enormous attention on account of their excellent optoelectronic properties. Especially, various MDCs can be constructed into vertical/lateral heterostructures with many novel optical and electrical properties, exhibiting great potential for the application in photodetectors. Therefore, the batch production of 2D MDCs and their heterostructures is crucial for the practical application. Recently, the vapour phase methods have been proved to be dependable for growing large-scale MDCs and related heterostructures with high quality. In this paper, we summarize the latest progress about the synthesis of 2D MDCs and their heterostructures by vapour phase methods. Particular focus is paid to the control of influence factors during the vapour phase growth process. Furthermore, the application of MDCs and their heterostructures in photodetectors with outstanding performance is also outlined. Finally, the challenges and prospects for the future application are presented.

     

Synthesis of magnetic two-dimensional materials by chemical vapor deposition

The development of magnetic two-dimensional (2D) materials in its infancy has generated an enormous amount of attention as it offers an ideal platform for the exploration of magnetic properties down to the 2D limit, paving the way for spintronic devices. Due to the nonnegligible advantages including time efficiency and simplified process, the facile bottom-up chemical vapor deposition (CVD) is regarded as a robust method to fabricate ultrathin magnetic nanosheets. Recently, some ultrathin magnets possessing fascinating properties have been successfully synthesized via CVD. Here, the recent researches toward magnetic 2D materials grown by CVD are systematically summarized with special emphasis on the fabrication methods. Then, heteroatoms doping and phase transition induced in CVD growth to bring or tune the magnetic properties in 2D materials are discussed. Characterizations and applications of these magnetic materials are also discussed and reviewed. Finally, some perspectives in need of urgent attention regarding the development of CVD-grown magnetic 2D materials are proposed.

     

Geometrical quasi-ballistic effects on thermal transport in nanostructured devices

We employ thermoreflectance thermal imaging to directly measure the steady-state two-dimensional(2D)temperature field generated by nanostructured heat sources deposited on silicon substrate with different geometrical configurations and characteristic sizes down to 400nm.The analysis of the results using Fourier's law not only breaks down as size scales down,but it alsofails to capture the impact of the geometry of the heat source.The substrate effective Fourier thermal conductivities fitted to wire-shaped and circular-shaped structures with identical characteristic lengths are found to display up to 40%mismatch.Remarkably,a hydrcxjynamic heat transport model reproduces the observed temperature fields for all device sizes and shapes using just intrinsic Si parameters,i.e.,a geometry and size-independent thermal conductivity and nonlocal length scale.The hydrodynamic model provides insight into the observed thermal response and of the contradictory Fourier predictions.We discuss the substantial Silicon hydrodynamic behavior at room temperature and contrast it to InGaAs,which shows less hydrodynamic effects due to dominant phonon-impurity scattering.     

Atomistic modeling and rational design of optothermal tweezers for targeted applications

Optical manipulation of micro/nanoscale objects is of importance in life sciences,colloidal science,and nanotechnology.Optothermal tweezers exhibit superior manipulation capability at low optical intensity.However,our implicit understanding of the working mechanism has limited the further applications and innovations of optothermal tweezers.Herein,we present an atomistic view of opto-thermo-electro-mechanic coupling in optothermal tweezers,which enables us to rationally design the tweezers for optimum performance in targeted applications.Specifically,we have revealed that the non-uniform temperature distribution induces water polarization and charge separation,which creates the thermoelectric field dominating the optothermal trapping.We further design experiments to systematically verify our atomistic simulations.Guided by our new model,we develop new types of optothermal tweezers of high performance using low-concentrated electrolytes.Moreover,we demonstrate the use of new tweezers in opto-thermophoretic separation of colloidal particles of the same size based on the difference in their surface charge,which has been challenging for conventional optical tweezers.With the atomistic understanding that enables the performance optimization and function expansion,optothermal tweezers will further their impacts.     

Oxygen-assisted direct growth of large-domain and high-quality graphene on glass targeting advanced optical filter applications

Growing high quality graphene films directly on glass by chemical vapor deposition(CVD)meets a growing demand for constructing high-performance electronic and optoelectronic devices.However,the graphene synthesized by prevailing methodologies is normally of polycrystalline nature with high nucleation density and limited domain size,which significantly handicaps its overall properties and device performances.Herein,we report an oxygen-assisted CVD strategy to allow the direct synthesis of 6-inch-scale graphene glass harvesting markedly increased graphene domain size(from 0.2 to 1.8μm).Significantly,as-produced graphene glass attains record high electrical conductivity(realizing a sheet resistance of 900Ω·sq^-1at a visible-light transmittance of 92%)amongst the state-of-the-art counterparts,readily serving as transparent electrodes for fabricating high-performance optical filter devices.This work might open a new avenue for the scalable production and application of emerging graphene glass materials with high quality and low cost.     

Superhydrophobic,photo-sterilize,and reusable mask based on graphene nanosheet-embedded carbon (GNEC) film

The 2019 coronavirus disease(COVID-19)has affected more than 200 countries.Wearing masks can effectively cut off the virus spreading route since the coronavirus is mainly spreading by respiratory droplets.However,the common surgical masks cannot be reused,resulting in the increasing economic and resource consumption around the world.Herein,we report a superhydrophobic,photo-sterilize,and reusable mask based on graphene nanosheet-embedded carbon(GNEC)film,with high-density edges of standing structured graphene nanosheets.The GNEC mask exhibits an excellent hydrophobic ability(water contact angle:157.9°)and an outstanding filtration efficiency with 100%bacterial filtration efficiency(BFE).In addition,the GNEC mask shows the prominent photo-sterilize performance,heating up to 110℃quickly under the solar illumination.These high performances may facilitate the combat against the COVID-19 outbreaks,while the reusable masks help reducing the economic and resource consumption.     

Integrated hetero-nanoelectrodes for plasmon-enhanced electrocatalysis of hydrogen evolution

Hetero-nanostructures of plasmonic metals and semiconductors have attracted increasing attention in the field of photocatalysis.However,most of the hetero-nanostructured catalysts are randomly arranged and therefore require comprehensive structural design for optimizing their properties.Herein,we report the robust construction of hierarchical hetero-nanostructures where gold(Au)nanorods and molybdenum disulfide(Mo S₂)quantum sheets(QSs)are integrated in highly ordered arrays.Such construction is achieved through porous anodic alumina(PAA)template-assisted electrodeposition.The as-fabricated hetero-nanostructures demonstrate exciting electrocatalysis towards hydrogen evolution reaction(HER).Both plasmon-induced hot-electron injection and plasmonic scattering/reabsorption mechanisms are determinative to the enhanced electrocatalytic performances.Notably,broadband photoresponses of HER activity in the visible range are observed,indicating their superiority compared with random systems.Such integrated hetero-nanoelectrodes could provide a powerful platform for conversion and utilization of solar energy,meanwhile would greatly prompt the production and exploration of ordered nanoelectrodes.     

Corrosion formation and phase transformation of nickel-iron hydroxide nanosheets array for efficient water oxidation

Designing earth-abundant electrocatalysts with high performance towards water oxidation is highly decisive for the sustainable energy technologies. This study develops a facile natural corrosion approach to fabricate nickel-iron hydroxides for water oxidation. The resulted electrode demonstrates an outstanding activity and stability with an overpotential of 275 mV to deliver 10 mA·cm⁻². Experimental and theoretical results suggest the corrosion-induced formation of hydroxides and their transformation to oxyhydroxides would account for this excellent performance. This work not only provides an interesting corrosion approach for the fabrication of excellent water oxidation electrode, but also bridges traditional corrosion engineering and novel materials fabrication, which would offer some insights in the innovative principles for nanomaterials and energy technologies.

     

Direct aerobic oxidation of monoalcohol and diols to acetals using tandem Ru@MOF catalysts

The aerobic oxidation of monoalcohols and diols to acetals is an important academic and industrial challenge for the production of fine chemicals and intermediates.The existing methods usually rely on a two-step process in which alcohols are first oxidized to aldehydes over metal catalysts(Ru,Pt,Pd)and then acetalized using acids.Due to the instability of aldehydes,how to avoid over-oxidation to their respective carboxylic acids and esters is a long-standing challenge.For this reason,certain non-conjugated dialdehydes have never been successfully produced from diol oxidation.Hereby we report a Ru@metal-organic framework(MOF)tandem catalyst containing ultra-fine Ru nanoparticles(<2 nm)for direct alcohol to acetal conversion of monoalcohol and diols with noformation of carboxylic acids.Mechanistic study reveals that the presence of Lewis acid sites in the MOF work in concert with Ru active sites to promptly convert aldehydes to acetals thereby effectively suppressing the formation of over-oxidation byproducts.     

Opto-valleytronics in the 2D van der Waals heterostructure

The development of information processing devices with minimum carbon emission is crucial in this information age. One of the approaches to tackle this challenge is by using valleys (local extremum points in the momentum space) to encode the information instead of charges. The valley information in some material such as monolayer transition metal dichalcogenide (TMD) can be controlled by using circularly polarized light. This opens a new field called opto-valleytronics. In this article, we first review the valley physics in monolayer TMD and two-dimensional (2D) heterostructure composed of monolayer TMD and other materials. Such 2D heterostructure has been shown to exhibit interesting phenomena such as interlayer exciton, magnetic proximity effect, and spin-orbit proximity effect, which is beneficial for opto-valleytronics application. We then review some of the optical valley control methods that have been used in the monolayer TMD and the 2D heterostructure. Finally, a summary and outlook of the 2D heterostructure opto-valleytronics are given.