Three-dimensional Porous Networks of Ultra-long Electrospun SnO_2 Nanotubes with High Photocatalytic Performance

Recent progress in nanoscience and nanotechnology creates new opportunities in the design of novel SnO2 nanomaterials for photocatalysis and photoelectrochemical. Herein, we firstly highlight a facile method to prepare threedimensional porous networks of ultra-long SnO2 nanotubes through the single capillary electrospinning technique.Compared with the traditional SnO2 nanofibers, the as-obtained three-dimensional porous networks show enhancement of photocurrent and photocatalytic activity, which could be ascribed to its improved light-harvesting efficiency and high separation efficiency of photogenerated electron–hole pairs. Besides, the synthesis route delivered three-dimensional sheets on the basis of interwoven nanofibrous networks, which can be readily recycled for the desirable circular application of a potent photocatalyst system.

Polydopamine-coated photoautotrophic bacteria for improving extracellular electron transfer in living photovoltaics

Living photovoltaics are microbial electrochemical devices that use whole cell–electrode interactions to convert solar energy to electricity.The bottleneck in these technologies is the limited electron transfer between the microbe and the electrode surface.This study focuses on enhancing this transfer by engineering a polydopamine(PDA)coating on the outer membrane of the photosynthetic microbe Synechocystis sp.PCC6803.This coating provides a conductive nanoparticle shell to increase electrode adhesion and improve microbial charge extraction.A combination of scanning electron microscopy(SEM),transmission electron microscopy(TEM),UV–Vis absorption,and Raman spectroscopy measurements were used to characterize the nanoparticle shell under various synthesis conditions.The cell viability and activity were further assessed through oxygen evolution,growth curve,and confocal fluorescence microscopy measurements.The results show sustained cell growth and detectable PDA surface coverage under slightly alkaline conditions(pH 7.5)and at low initial dopamine(DA)concentrations(1 mM).The exoelectrogenicity of the cells prepared under these conditions was also characterized through cyclic voltammetry(CV)and chronoamperometry(CA).The measurements show a three-fold enhancement in the photocurrent at an applied bias of 0.3 V(vs.Ag/AgCl[3 M KCl])compared to non-coated cells.This study thus lays the framework for engineering the next generation of living photovoltaics with improved performances using biosynthetic electrodes.

In vivo polydopamine coating of Rhodobacter sphaeroides for enhanced electron transfer

Recent advances in coupling light-harvesting microorganisms with electronic components have led to a new generation of biohybrid devices based on microbial photocatalysts.These devices are limited by the poorly conductive interface between phototrophs and synthetic materials that inhibit charge transfer.This study focuses on overcoming this bottleneck through the metabolically-driven encapsulation of photosynthetic cells with a bio-inspired conductive polymer.Cells of the purple non sulfur bacterium Rhodobacter sphaeroides were coated with a polydopamine(PDA)nanoparticle layer via the self-polymerization of dopamine under anaerobic conditions.The treated cells show preserved light absorption of the photosynthetic pigments in the presence of dopamine concentrations ranging between 0.05–3.5 mM.The thickness and nanoparticle formation of the membrane-associated PDA matrix were further shown to vary with the dopamine concentrations in this range.Compared to uncoated cells,the encapsulated cells show up to a 20-fold enhancement in transient photocurrent measurements under mediatorless conditions.The biologically synthesized PDA can thus act as a matrix for electronically coupling the light-harvesting metabolisms of cells with conductive surfaces.

Determination of hydroxyl radical in Fenton system

Under visible light illumination, 2,3-diaminophenazine （DAPN） was generated from the oxidation of o-phenylenediamine （OPDA） in Fe^3＋/H2O2 solution. Hydroxyl radical （＊OH） produced in this system was determined by directly measuring the concentration of DAPN. In comparison with the traditional methods, the determination is more accurate and simple.

Fullerene(C_(60)) Nanowires: The Preparation,Characterization, and Potential Applications

Fullerene(C_(60))nanowires have attracted significant attention in the past two decades due to their outstanding chemical and physical properties,which render the material a wide range of potential applications.Much effort has been devoted to exploring the growth methods,structural and compositional characterizations,and application-related investigations of this novel carbon nanomaterial.Here,we present a review of C_(60)nanowires in which we will first describe the recent development in the material preparations,analytical techniques,crystal structures,chemical compositions,and the investigations of polymerization processes.Afterward,we will discuss the mechanistic studies on the nanowires’growth as the mechanism research is of great importance for their size control,large-scale preparation,and for the exploration of applications in a wide range of fields.Finally,we will discuss the potential applications in several directions,including optical,electrical,mechanical,and biological fields,as well as our perspectives to future developments.

Anaerobic Co-Digestion of Fish Processing Waste with Cow Manure and Waste of Market (Rests of Fruits and Vegetables): A Lab Scale Batch Test

The aim of this work was to use fish processing waste (FW) as main substrate for anaerobic digestion. To enhance the biogas production of FW, co-digestion was done with two other substrates: cow dung (CD) and waste of market (MW). Batch test was carried out in an 1 L glass digester in a temperature controlled chamber at 38°C. The following mixtures were carried out: FW with CD respectively at different ratios 100:0% (A), 80:20% (B) and 60:40% (C);FW with MW at the following ratio 80:20% (D);FW with CD and MW respectively at these ratios 80:10:10% (F) and 60:20:20% (G). The biogas produced was measured using a milligas counter® and the volume of gas was recorded. The gas composition was determined using gas chromatography. With a pH stable for raw substrates and mixtures, TS and VS (%TS) contents for FW were respectively 31.01% and 91.55%. Between 3 to 13 days of experimentation, the highest flow rate was observed. The percentage of methane was more important for mixtures B and D, 61% and 59% respectively. pH and VOA/TIC were stable at the end of the batch test for all mixtures, meaning that the organic matter was already well digested. The highest values of Volatile Solid Removal (VSR) were found for mixtures C, D, F and G. Therefore, the promising mixtures for next experimentations in large scale are B and D.

Advancing and demonstrating the Impact Indices method to screen the sensitivity of building energy use to occupant behaviour

A critical gap between the occupant behaviour research field and the building engineering practice limits the integration of occupant-centric strategies into simulation-aided building design and operation.Closing this gap would contribute to the implementation of strategies that improve the occupants’well-being while reducing the buildings’environmental footprint.In this view,it is urgent to develop guidelines,standardised methods,and supporting tools that facilitate the integration of advanced occupant behaviour models into the simulation studies.One important step that needs to be fully integrated into the simulation workflow is the identification of influential and non-influential occupant behaviour aspects for a given simulation problem.Accordingly,this article advances and demonstrates the application of the Impact Indices method,a fast and efficient method for screening the potential impact of occupant behaviour on the heating and cooling demand.Specifically,the method now allows the calculation of Impact Indices quantifying the sensitivity of building energy use to occupancy,lighting use,plug-load appliances use,and blind operation at any spatial and temporal resolution.Hence,users can apply it in more detailed heating and cooling scenarios without losing information.Furthermore,they can identify which components in building design and operation require more sophisticated occupant behaviour models.An office building is used as a real case study to illustrate the application of the method and asses its performance against a one-factor-at-a-time sensitivity analysis.The Impact Indices method indicates that occupancy,lighting use and plug-load appliances have the greatest impact on the annual cooling demand of the studied office building;blind operation is influential only in the west and south façades of the building.Finally,potential applications of the method in building design and operation practice are discussed.

MnFe2O4 nanoparticles as new catalyst for oxidative degradation of phenol by peroxydisulfate

Manganese ferrite nanopowder was prepared by thermal decomposition at 400℃ of the gel synthesized from manganese and iron nitrates and polyvinyl alcohol. X-ray diffractometry evidenced that manganese ferrite was formed as single crystalline phase at this temperature. Scanning electron microscope images evidenced the formation of very fine spherical particles （d 〈 11 nm） of manganese ferrite, with specific surface area of 147 m2/g. The powder obtained at 400℃ was used as a catalyst for the oxidative degradation of phenol in aqueous solutions, in the presence of potassium peroxydisulfate as oxidant. High phenol removal efficiencies above 90% were reached at： pH 3-3.5, phenol initial concentration around 50 mg/L, peroxydisulfate：phenol mass ratio 10：1, and catalyst dose 3 g/L. Total organic carbon measurements showed that the degradation of phenol goes, under these conditions, to mineralization in an extent of 60%.

Planar Li growth on Li_(21)Si_(5)modified Li metal for the stabilization of anode

Lithium(Li)metal is widely considered the ultimate anode for future rechargeable batteries.However,dendritic growth and related parasitic reactions during long-term cycling often lead to severe safety hazards and catastrophic failure.Herein,we fabricate a hybrid anode by coating single-phase Li_(21)Si_(5)on lithium metal.The resultant electrodes show a stable cycle and depressed polarization in symmetric and half cells.A planar plating/stripping behavior is observed on the modified anode.The investigation of the interplay of Li and Li_(21)Si_(5)shows relatively large adsorption energy in the Li-Si system.The deposition and stripping are surface processes,and Li_(21)Si_(5)maintains its intrinsic phase structure.The deposited Li layer around Li_(21)Si_(5)also has the advantage of diminished preferred orientation,which also contributes to the planar growth of Li.Both LiFePO4(LFP)and LiNi1/3Co1/3 Mn1/3O2(NCM)cathodes were applied to further demonstrate the enhanced rate and cycle performance.

Sintering behavior of combusted iron powder in a packed bed reactor with nitrogen and hydrogen

Sintering behavior of micron-sized combusted iron powder is studied in a packed bed reactor,at various temperatures under inert(nitrogen)and reducing(hydrogen)conditions.Compression tests are subsequently used to quantify the degree of sintering.A sintering model,based on the formation of a solid bridge through solid state surface diffusion of iron atoms,matches the experimental results.Sintering of combusted iron occurs at temperatures≥575°C in both nitrogen and hydrogen atmospheres and increases exponentially with temperature.The observed decrease in reduction rate at high temperatures is not caused by the sintering process but by the formation of wüstite as an intermediate species,leading to the formation of a dense iron layer.Iron whiskers form at high temperatures(≥700°C)in combination with low reduction rates(≤25 vol%H2),leading to the production of sub-micron fines.

A database of experimentally measured lithium solid electrolyte conductivities evaluated with machine learning

The application of machine learning models to predict material properties is determined by the availability of high-quality data.We present an expert-curated dataset of lithium ion conductors and associated lithium ion conductivities measured by a.c.impedance spectroscopy.This dataset has 820 entries collected from 214 sources;entries contain a chemical composition,an expert-assigned structural label,and ionic conductivity at a specific temperature(from 5 to 873°C).There are 403 unique chemical compositions with an associated ionic conductivity near room temperature(15–35°C).The materials contained in this dataset are placed in the context of compounds reported in the Inorganic Crystal Structure Database with unsupervised machine learning and the Element Movers Distance.This dataset is used to train a CrabNet-based classifier to estimate whether a chemical composition has high or low ionic conductivity.This classifier is a practical tool to aid experimentalists in prioritizing candidates for further investigation as lithium ion conductors.

Lattice Boltzmann Simulations of Two Linear Microswimmers Using the Immersed Boundary Method

The performance of a single or the collection of microswimmers strongly depends on the hydrodynamic coupling among their constituents and themselves.We present a numerical study for a single and a pair of microswimmers based on lattice Boltzmann method(LBM)simulations.Our numerical algorithm consists of two separable parts.Lagrange polynomials provide a discretization of the microswimmers and the lattice Boltzmann method captures the dynamics of the surrounding fluid.The two components couple via an immersed boundary method.We present data for a single swimmer system and our data also show the onset of collective effects and,in particular,an overall velocity increment of clusters of swimmers.

Template-directed assembly of pentacene molecules on epitaxial graphene on Ru（0001）

The template-directed assembly of planar pentacene molecules on epitaxial graphene grown on Ru（0001） （G/Ru） has been investigated by means of low-temperature scanning tunneling microscopy （STM） and density functional theory （DFT） calculations. STM experiments find that pentacene adopts a highly selective and dispersed growth mode in the initial stage. By using DFT calculations including van der Waals interactions, we find that the configuration with pentacene adsorbed on face-centered cubic （fcc） regions of G/Ru is the most stable one, which accounts for the selective adsorption at low coverage. Moreover, at high coverage, we have successfully controlled the molecular assembly from amorphous, local ordering, to long-range order by optimizing the deposition rate and substrate temperature.

Superior anti-corrosion and self-healing bi-functional polymer composite coatings with polydopamine modified mesoporous silica/graphene oxide

In this article,graphene oxide(GO)and benzotriazole-loaded mesoporous silica nanoparticles(BTA/MSNs)are combined on micro scale through the in situ polymerization of polydopamine(PDA),preparing a selfhealing bi-functional GO(fGO)used as nano-fillers for anti-corrosion enhancement of waterborne epoxy(WEP)coatings.Scanning electronic microscopy(SEM)images show that the BTA/MSNs are uniformly distributed on the surface of high aspect ratio GO nanosheets to endow GO nanocontainer characteristics.UV-vis profiles demonstrate that fGO has p H-controlled release function.Modulus at lowest frequency is generally used for comparing the corrosion resistance of organic coatings.Modulus at lowest frequency(1.42×10^(5)Ωcm^(2))after 30 days immersion in 3.5 wt.%Na Cl solution revealed 2 orders of magnitude higher that of blank WEP(1.17×10^(7)Ωcm^(2)).With artificial cracks on its coatings,fGO/WEP had no obvious rust compared with blank WEP after 240 h of immersion.We anticipate that self-healing and physical barrier bi-functional nanocontainers improve the traditional anticorrosion coating efficiency with better,longer-lasting performance for shipping,oil drilling or bridge maintenance.

Effective removal of Cd^2+ and Pb^2+ pollutants from wastewater by dielectrophoresis-assisted adsorption

Dielectrophoresis(DEP)was combined with adsorption(ADS)to simultaneously and effectively remove Cd^2+ and Pb^2+ species from aqueous solution.To implement the process,bentonite particles of submicro-meter size were used to first adsorb the heavy metal ions.These particles were subsequently trapped and removed by DEP.The effects of the adsorbent dosage,DEP cell voltage and the capture pool numbers on the removal rate were investigated in batch processes,which allowed us to determine the optimal experimental conditions.The high removal efficiency,97.3% and 99.9% for Cd^2+ and Pb^2+,respectively,were achieved when the ions are coexisting in the system.The microstructure of bentonite particles before and after ADS/DEP was examined by scanning electron microscopy.Our results suggest that the dielectrophoresis-assisted adsorption method has a high capability to remove the heavy metals from wastewater.

The unique carrier mobility of Janus MoSSe/GaN heterostructures

Heterostructure is an effective approach in modulating the physical and chemical behavior of materials. Here, the first-principles calculations were carried out to explore the structural, electronic, and carrier mobility properties of Janus MoSSe/GaN heterostructures. This heterostructure exhibits a superior high carrier mobility of 281.28 cm^(2)·V^(−1)·s^(−1) for electron carrier and 3951.2 cm^(2)·V^(−1)·s^(−1) for hole carrier. Particularly, the magnitude of the carrier mobility can be further tuned by Janus structure and stacking modes of the heterostructure. It is revealed that the equivalent mass and elastic moduli strongly affect the carrier mobility of the heterostructure, while the deformation potential contributes to the different carrier mobility for electron and hole of the heterostructure. These results suggest that the Janus MoSSe/GaN heterostructures have many potential applications for the unique carrier mobility.

Surfactant effect of antimony addition to the morphology of self-catalyzed InAS1-xSbx nanowires

The effect of Sb addition on the morphology of self-catalyzed InAsSb nanowires （NWs） has been systematically investigated. InAs NWs were grown by molecular beam epitaxy with and without antimony （Sb） flux. It is demonstrated that trace amounts of Sb flux are capable of tuning the geometry of NWs, i.e., enhancing lateral growth and suppressing axial growth. We attribute this behavior to the surfactant effect of Sb which results in modifications to the kinetic and thermodynamic processes. A thermodynamic mechanism that accounts for Sb segregation in InAsSb NWs is also elucidated. This study opens a new route towards precisely controlled NW geometries by means of Sb addition.

Electrochemical impedance spectroscopy analysis to accelerate electrocatalytic system innovation

Electrochemical impedance spectroscopy(EIS)is a well-established non-destructive characterization technique for assessing the efficacy of electrochemical energy storage and conversion systems.Electrocatalytic systems based on proton exchange membrane(PEM),including PEM fuel cells and PEM water electrolyzers,play a crucial role in renewable energy conversion through electricity–hydrogen interconversion.EIS,along with its derived analysis methods—equivalent circuit model(ECM),distribution of relaxation time(DRT),and dynamic EIS(DEIS),is widely utilized to extract valuable kinetics and impedance data.The acquired information affords critical insights into processes such as mass transfer,charge transfer,and proton transfer within PEM systems.This mini review surveys the role of EIS in optimizing components and investigating operational conditions to enhance the efficiency of PEM systems.In addition,it encapsulates the principles and applications of EIS-based methods like DRT and DEIS,highlighting their potential in the practical application of PEM systems.