Morphology-dependent interfacial interactions of Fe2O3 with Ag nanoparticles for determining the catalytic reduction of p-nitrophenol

In this work,we fabricated three kinds of Ag/Fe2O3 model catalysts with different morphologies to study the interfacial interactions between Ag and Fe2O3,and how they affected the catalytic activity in hydrogenation of p-nitrophenol was explored.The hydrothermal method was used to synthesize the metal oxide supported silver catalyst,with various morphologies including nanoplates(NPs),nanospheres(NSs),and nanocubes(NCs).The crystal structure,morphology and surface elements of the composite were investigated by various measurements,such as X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS).The catalytic activity was also evaluated by the reduction of p-nitrophenol to p-aminophenol.It was found that the activities of the above catalysts varied with the morphology of the support.Among them,Ag/Fe2O3 NPs promoted the highest performance,Ag/Fe2O3 NSs were slightly inferior,and Ag/Fe2O3 NCs were the worst.At last,we ascribed the remarkable activity of Ag/Fe2O3 NPs to the strong metal-support interactions between Ag and Fe2O3.

Dispersion of ultrafine alumina in modifier solution ——the role of polar interfacial interaction

Dispersion of ultrafine alumina suspension is examined by using particle size analyzer. The zeta potential and contact angle measurements were used to discuss the electrokinetic behavior and surface wettability of alumina in modifier solution, and to calculate the electrostatic interaction forces and interfacial interaction forces between alumina particles. The aggregation of ultrafine alumina occurs near its PZC. Addition of modifier increases the zeta potential of alumina and its surface hydrophilicity, resulting in increase of electrostatic and hydration repulsion. It makes the suspension of ultrafine alumina completely dispersed. The average particle size of the suspension is decreased from 1.73 μm in absence of modifier to 0.8 μm in the presence of tripolyphosphate. According to polar interfacial interaction approach, the hydration forces responsible for the stability of alumina suspension in the presence of modifier have also been obtained. The extended DLVO theory is successful to describe the dispersion behavior of ultrafine alumina in modifier solution.

Interfacial Interaction of CFRP Reinforced Steel Beam Structures

Due to the increase of service life,the phenomenon of performance degradation of bridge structures becomes more and more common.It is important to strengthen the bridge structures so as to restore the resistance level and extend the normal service life.Carbon fiber reinforced polymer(CFRP)materials are thus used for the assembly reinforcement of bridges for the advantages of high strength,light weight,corrosion resistance and long-term stability of physical and chemical properties,etc.In view of this,based on the previous theoretical study and the established formula of the interfacial shear stress of CFRP reinforced steel beam and the normal stress of CFRP plate,this paper discusses the sensitive parameters that affect the interfacial interaction of CFRP strengthened beam structures.Through the analysis,the priority design indicators and suggestions are accordingly given for the design of reinforced beam structures.Young’s modulus of CFRP composite and shear modulus of the adhesive have the greatest influence on the interfacial interaction,which should be carefully considered.It is suggested that CFRP material with Ec close to 300 GPa and thickness no less than 3 mm,and adhesive material with Ga less than 5 GPa and 3-mm thickness can be adopted in CFRP reinforced steel beam.The conclusions of this paper can provide guidance for the interfacial damage control of CFRP reinforced steel beam structures.

Interfacial friction at action: Interactions, regulation, and applications

Friction is a fundamental force that impacts almost all interface-related applications.Over the past decade,there is a revival in our basic understanding and practical applications of the friction.In this review,we discuss the recent progress on solid–liquid interfacial friction from the perspective of interfaces.We first discuss the fundamentals and theoretical evolution of solid–liquid interfacial friction based on both bulk interactions and molecular interactions.Then,we summarize the interfacial friction regulation strategies manifested in both natural surfaces and artificial systems,focusing on how liquid,solid,gas,and hydrodynamic coupling actions mediate interfacial friction.Next,we discuss some practical applications that are inhibited or reinforced by interfacial friction.At last,we present the challenges to further understand and regulate interfacial friction.

Alkaline hydrogen production promoted by small-molecule modification on flowerlike Co_(2)(OH)_(2)CO_(3)

Developing a low-cost and high-efficiency nonprecious metal-based catalyst for hydrogen evolution reaction(HER) is of great significance for the utilization of hydrogen energy.In this work,we report a molecular-modification strategy to fabricate a self-supported hydrogen evolution electrode,specially by grafting the macrocyclic molecules(HHTP=2,3,6,7,10,11-hexahydroxytriphenylene) on the surface of a cobaltous dihydroxy carbonate(COC) seed layer.The HHTP-COC electrode is endowed with a rodlike structure,which provides favorable access for charge transportation and mass exchange.The macrocyclic molecule structure in HHTP can be grafted on COC and improve the electrical conductivity,while the interaction between HHTP and COC induces the rearrangement of charge configuration on the surface.Due to the combination effects of several aspects,the HHTP-COC electrode achieves astonishing HER activity,with a low overpotential of 61.0 mV(η_(10),at the current density of 10 mA cm^(-2)) and excellent stability in alkaline condition.This kind of interface engineering based on the organic molecules can be applied to the design and manufacture of electrocatalysts in the field of energy conversion and storage.

Simultaneously improving the EMI shielding performances and mechanical properties of CF/PEKK composites via MXene interfacial modification

In this study, two-dimensional MXene (Ti3 C2 Tx ) was employed to modify the interface of carbon fiber-reinforced polyetherketoneketone (CF/PEKK) composites, in order to simultaneously improve the electromagnetic interference (EMI) shielding performances and mechanical properties. The obtained CF/PEKK composites possessed outstanding EMI and mechanical performances, as anticipated. Specifically, the CF/PEKK composites modified with MXene at 1 mg mL–1 exhibited an excellent EMI shielding effectiveness of 65.2 dB in the X-band, a 103.1% enhancement compared with the unmodified CF/PEKK composites. The attractive EMI shielding performances of CF/PEKK composites originated from enhanced ohmic losses and multiple reflections of electromagnetic waves with the help of the MXene and CF layers. In addition, CF/PEKK composites achieved the best mechanical properties by optimizing the dispersion concentration of MXene to 0.1 mg mL–1 . The flexural strength, flexural modulus, and interlaminar shear strength of CF/PEKK composites reached 1127 MPa, 81 GPa, and 89 MPa, which were 28.5%, 9.5%, and 29.7% higher than that of the unmodified CF/PEKK composites, respectively. Such improvement in mechanical properties could be ascribed to the comprehensive effect of mechanical interlocking, hydrogen bonds, and Van der Waals forces between the introduced MXene and CF, PEKK, respectively.

MOF-Derived ZnS Nanodots/Ti_(3)C_(2)T_(x) MXene Hybrids Boosting Superior Lithium Storage Performance

ZnS has great potentials as an anode for lithium storage because of its high theoretical capacity and resource abundance;however,the large volume expansion accompanied with structural collapse and low conductivity of ZnS cause severe capacity fading and inferior rate capability during lithium storage. Herein,0D-2 D ZnS nanodots/Ti_(3)C_(2)T_x MXene hybrids are prepared by anchoring ZnS nanodots on Ti_(3)C_(2)T_(x) MXene nanosheets through coordination modulation between MXene and MOF precursor(ZIF-8) followed with sulfidation. The MXene substratecoupled with the ZnS nanodots can synergistically accommodate volume variation of ZnS over charge–discharge to realize stable cyclability. As revealed by XPS characterizations and DFT calculations,the strong interfacial interaction between ZnS nanodots and MXene nanosheets can boost fast electron/lithium-ion transfer to achieve excellent electrochemical activity and kinetics for lithium storage. Thereby,the as-prepared ZnS nanodots/MXene hybrid exhibits a high capacity of 726.8 mAh g^(-1) at 30 mA g^(-1),superior cyclic stability(462.8 mAh g^(-1) after 1000 cycles at 0.5 A g^(-1)),and excellent rate performance. The present results provide new insights into the understanding of the lithium storage mechanism of ZnS and the revealing of the e ects of interfacial interaction on lithium storage performance enhancement.

Aggregation/dispersion of ultrafine silica in flotagent solution

The aggregation/dispersion of ultrafine particles is of interest for both fundamental and practical perspective. These behaviors of ultrafine silica in flotagent solution and the heter coagulation of silica and alumina were examined using particle size analyzer, electrokinetic potential, contact angle measurements. The flotation reagents have a pronounced effect on the aggregation or dispersion behaviors of ultrafine silica suspensions. Collector dodecylamine chloride renders silica surfaces hydrophobic and the aggregation between silica particles takes place. Modifier tripolyphosphate makes the silica surface completely hydrophilic and enhances the stability of silica suspension. These experimental results can be explained based on the extended DLVO theory by considering polar interfacial interaction between particle surfaces.

Fabrication of segregated poly(arylene sulfide sulfone)/graphene nanoplate composites reinforced by polymer fibers for electromagnetic interference shielding

Poly(arylene sulfide sulfone)/graphene nanoplate(PASS/GNP) composites with segregated structure based on continuous polymer fiber skeletons were fabricated by coating a thin conductive layer on the PASS fibers and then performing compression molding. The formation of a unique segregated conductive network endowed the PASS/GNP composites with high electrical conductivity and excellent electromagnetic interference(EMI) shielding effectiveness(SE), reaching 17.8 S/m and 30.1 d B, respectively, when the content of the GNPs in the conductive layer was 20 wt%. The PASS/GNP composites also exhibited outstanding mechanical properties, which was attributed to the continuous PASS fiber skeletons that could withstand large loads and the strong interfacial interaction between the conductive layers and the PASS fibers that could provide good stress transfer. This approach is suitable for most soluble polymers.

Interfacial electronic interaction enabling exposed Pt(110)facets with high specific activity in hydrogen evolution reaction

To achieve a complete industrial chain of hydrogen energy,the development of efficient electrocatalysts for hydrogen evolution reaction(HER)is of great concerns.Herein,a nickel nitride supported platinum(Pt)catalyst with highly exposed Pt(110)facets(Pt_((110))-Ni_(3)N)is obtained for catalyzing HER.Combined X-ray spectra and density functional theory studies demonstrate that the interfacial electronic interaction between Pt and Ni3N support can promote the hydrogen evolution on Pt(110)facets by weakening hydrogen adsorption.As a result,the Pt_((110))-Ni_(3)N catalyst delivers an obviously higher specific activity than commercial 20 wt.%Pt/C in acidic media.This work suggests that the suitable interface modulation may play a vital role in rationally designing advanced electrocatalysts.

Carbon nanotube supported PtOx nanoparticles with hybrid chemical states for efficient hydrogen evolution

Efficient electrocatalysts for hydrogen evolution reaction(HER) in alkaline solution are highly required for water splitting.Here we design an ultra-small PtOx nanoparticle with hybrid Pt chemical states on carbon nanotubes as highly efficient alkaline HER catalyst,which shows a low overpotential of 19.4 mV at 10 mA cm^(-2),a high mass activity of 5.56 A mg_(Pt)^(-1) at 0.1 V, and a stable durability for at least 20 h.The HER performance is better than that of the benchmark 20 wt% Pt/C while the Pt content in the catalyst is only about one tenth of that in Pt/C.It also represents one of the best catalysts ever reported for HER in alkaline solution.Synchrotron radiation X-ray absorption spectroscopy reveals that the efficient and stable alkaline HER performance can be attributed to the favorable design of hybrid chemical states of Pt with carbon nanotubes,which exhibits abundant surface Pt-O as active catalytic sites and forms stable Pt-C interfacial interaction to both anchor the NPs and improve the synergistic effect between catalyst and substrate.

Structural Performance of Smart CFRP-FBG Reinforced Steel Beams

Many beam structures suffer from gradual performance degradation with the increase of service life.To recover the bearing capacity of these beams,carbon fiber reinforced polymer(CFRP)plates are developed to attached on the beam bottom.To check the structural performance of the CFRP reinforced beams,smart CFRP plate with FBGs in series is designed and LVDTs are adopted to measure the deformations.The deflection of the reinforced beam is given based on the elastic conversion cross-section method.The experimental results validate the effectiveness of the proposed algorithm.The study shows that the CFRP reinforced zone has a larger flexural rigidity than the pure steel beam zone.The general distribution of the deflection along the span of the CFRP reinforced beam can be described by the proposed formula.It provides a scientific design guidance for the deflection control of CFRP reinforced structures.

The discovery of interfacial electronic interaction within cobalt boride@MXene for high performance lithium-sulfur batteries

Lithium-sulfur battery is strongly considered as the most promising next-generation energy storage system because of the high theoretical specific capacity.The serious"shuttle effect"and sluggish reaction kinetic limited the commercial application of lithium-sulfur battery.Many hetero structure s were applied to accelerate polysulfides conversion and suppress their migration in lithium-sulfur batteries.Nevertheless,the effect of the interface in heterostructure was not clear.Here,the Co_(2)B@MXene heterostructure is synthesized through chemical reactions at room temperature and employed as the interlayer material for Li-S batteries.The theoretical calculations and experimental results indicate that the interfacial electronic interaction of Co_(2)B@MXene induce the transfer of electrons from Co_(2)B to MXene,enhancing the catalytic ability and favoring fast redox kinetics of the polysulfides,and the theoretical calculations also reveal the underlying mechanisms for the electron transfer is that the two materials have different Fermi energy levels.The cell with Co_(2)B@MXene exhibits a high initial capacity of1577 mAh/g at 0.1 C and an ultralow capacity decay of 0.0088%per cycle over 2000 cycles at 2 C.Even at5.1 mg/cm^(2) of sulfur loading,the cell with Co_(2)B@MXene delivers 5.2 mAh/cm^(2) at 0.2 C.

Reactive processing of poly(lactic acid)/poly(ethylene octene) blend film with tailored interfacial intermolecular entanglement and toughening mechanism

In order to obtain a uniform and effectively toughened poly(lactic acid)film by blending with low content of poly(ethylene octene)(POE)with high elasticity,the tailored interfacial intermolecular interaction and entanglement between the two phases of the PLA/POE blend was innovatively constructed via the facile reactive melt blending process through the reaction of the epoxy/anhydride groups grafted on the POE chains with the end groups of PLA chains(PLA/GPOE-MPOE).It was observed that POE domains were embedded tightly in PLA matrix with a fuzzy interface and abundant interface transition area,and the impact fractured surface of the blend showed an obvious plastic deformation with less occurrence of fibrillation of PLA matrix or interfacial de-bonding.Compared with neat PLA and directly blended PLA/POE blends,the PLA/GPOE-MPOE blend exhibited much higher complex viscosity/storage modulus,much lower tanδvalues in the terminal region,and obvious strain-hardening behavior.The deviation in viscoelastic behavior of PLA/GPOE-MPOE from linear PLA indicated the enhanced molecular entanglement between the long-branched chains,resulting in an enhancement of the stretching ability during biaxial drawing of the blend.Uniform PLA/GPOE-MPOE films with draw ratio as high as 7×7 were obtained through biaxial stretching,which showed much higher tensile strength and the elongation at break than that of neat PLA and PLA/POE film.This work provides a facile method for fabricating toughening PLA films with application potentials.

Mechanisms of yttrium on the wettability,surface tension and interactions between Ni-20Co-20Cr-10Al-ξY alloys and MgO ceramics

The mechanisms of Y on the wettability,surface tension,and interactions between the Ni-20 Co-20 Cr-10 Al-ξY alloys and MgO ceramics at 1873 K were investigated by sessile drop experiments.The results of nonlinear fitting showed that the equilibrium contact angles and Y concentrations were approximately in accord with the log-normal distribution law.The equilibrium contact angles changed from 101.5°to 140.5°with Y increasing from 0 wt.%to 1.23 wt.%.Cross-sectional microstructure observations revealed that the thermal dissociation of ceramics occurred and the released[O]atoms can react with Y to produce Y_(2)O_(3) reaction layer along three-phase interphase area.Wetting kinetics analyses indicated that surface tension of the melt droplets had been positively correlated with the Y concentrations,and it increased from 737.8–1045.1 mN/m.Meanwhile,the pinning effect of the rough substrate surface on the three-phase line hindered the spreading of the liquid on ceramics.The change in total free energy of the alloys/ceramics system was considered as the key factor affecting the wettability.Moreover,the surface morphology and thermodynamic stability of ceramics also had some influence on the wettability.

Dual Effects of Interfacial Interaction and Geometric Constraints on Structural Formation of Poly(butylene terephthalate)Nanorods

When the size of the material is smaller than the size of the molecular chain,new nanostructures can be formed by crystallizing polymers in nanoporous alumina.However,the effect of pore wall and geometric constraints on polymer nanostructures remains unclear.In this study,we demonstrate three new restricted nanostructures{upright-,flat-and tilting-ring}in polybutylene terephthalate(PBT)nanorods prepared from nanoporous alumina.The dual effects of geometrical constraints and interfacial interactions on the formation of PBT nanostructures were investigated for the first time by using X-ray diffraction and Cerius^(2) modeling packages.Under weak constraints,the interaction between pore wall and the PBT rings is dominant and the ring plane tends to be parallel to the pore wall and radiate outward to grow the upright-ring crystals.Surprisingly,in strong 2D confinement,a structural formation reversal occurs and geometrical constraints overpower the effect of pore wall.Rings tend to pile up vertically or obliquely along the long axis of the rod,so the flat-and tilting-ring crystals are predominate in the constrained system.In principle,our study of the nanostructure formation based on the geometrical constraints and the pore wall interfacial effects could provide a new route to manipulate the chain assembly at the nanoscale,further improving the performance of polymer nanomaterial.

Atomic insight into the functionalization of cellulose nanofiber on durability of epoxy nanocomposites

Chemical functionalization is an effective approach to address interfacial deterioration caused by environmental exposure in cellulose nanofiber(CNF)-epoxy nanocomposites.However,how functionalization affects interfacial deterioration and durability of nanocomposites in erosive environment is still lacked.In this work,the global mechanical properties and local interfacial intermolecular behavior of pristine and functionalized CNF-reinforced nanocomposites are investigated through molecular dynamics simulations.The results show that functionalization can enhance the interfacial energy barrier and debonding stress by 43%and 57%,respectively.Functionalized CNF inhibits the slippage of epoxy chains,ensuring better interfacial adhesion and efficient stress transfer between fiber and matrix.Functional groups promote the formation of interfacial bridging and topological structures and weaken the hydrogen bonding ability of water molecules,leading to stronger intermolecular adsorption effect and better interfacial integrity.The epoxy molecular configuration evolution and intermolecular interactions,caused by the functionalization of CNF in the interfacial region,enhance the interfacial erosion resistance,contributing to the durability of the nanocomposites.This study reveals the in-depth interfacial deterioration mechanism of functionalized nanocomposites under erosive environment,inspiring a novel strategy for the design of durable CNF-reinforced nanocomposites.

Amine functionalization on thermal and mechanical behaviors of graphite nanofibers-loaded epoxy composites

With the growing demand for faster and more powerful computing,effective heat dissipation is essential to ensure the longevity,reliability,and high performance of electronic systems.In the field of modern electronic packaging materials,there is a great need for graphitic material-loaded polymeric composites(GPCs)with excellent thermal conductivities.However,the enhancement efficiency of GPCs is hindered by the agglomeration of fillers and the interfacial thermal resistance caused by the lack of continuous thermally conductive pathways between the filler and matrix.Understanding the interfaces between filler and matrix is of great importance in optimizing the performances of GPCs.Here,we fabricated graphite nanofibers(GNF)-loaded nanocomposites using acid-functionalized GNF(AGNF)and acidtetraethylenepentamine-functionalized(TGNF)as a filler and epoxy resin as a matrix with different GNF loading contents to explore the interfacial properties of the nanocomposites.The optimal GNF loading for AGNF was 0.5 wt.%,while the TGNF showed 0.75 wt.%.The highest thermal conductivity(0.51 W m^(−1) K^(−1))and fracture toughness(25.8 MPa m^(1/2))values were found in the TGNF-loaded nanocomposites with a fraction of 0.75 wt.%,representing enhancements of∼145%and∼400%,respectively,compared to those of neat nanocomposites.The experimental data presented herein demonstrate that the interfacial properties play a significant role in enhancing the thermal and mechanical performances of the nanocomposites.The present approach is expected to serve as a valuable tool in the design of conductive polymeric nanocomposites for further practical applications,such as thermal interface materials and packaging of high-power electric devices.

High mass-loadingα-Fe_(2)O_(3)nanoparticles anchored on nitrogen-doped wood carbon for high-energy-density supercapacitor

The trade-off between mass-loading and cycling stability is always a big challenge for iron oxide-based electrodes.Herein,α-Fe_(2)O_(3)nanoparticles uniformly anchored on nitrogen-doped wood carbons with high mass-loading have been synthesized via a facile electrodeposition method accompanied by post-heating treatment.The resultant composite delivers a high specific capacitance of 603 F/g at 0.1 A/g and superior capacitance retention of 85.5%after 10,000 cycles at 10 A/g,indicating excellent long-term cycling stability.Such excellent electrochemical performance can be attributed to the synergistic effects ofα-Fe_(2)O_(3)nanoparticles and the conductive matrix as well as the formation of interfacial Fe-O-C bonding,which enables the composite electrode to provide plenty of accessible redox active sites,sufficient electron transport and electrolyte ions diffusion,and robust interfacial interaction.Consequently,the asymmetrical supercapacitor exhibits a high energy density of 30.3 Wh/kg at 125W/kg,suggesting its great potential forpracticalapplications.

Fe doped g-C_(3)N_(4) composited ZnIn_(2)S_(4) promoting Cr(Ⅵ) photoreduction

30% Fe CN/ZIS(30% Fe doped g-C_(3)N_(4)composited ZnIn_(2)S_(4)) was synthesized by a simple water bath method, via in-situ growth of abundant well-dispersed ZnIn_(2)S_(4)nanosheets on the Fe doped g-C_(3)N_(4)surface. Experimental results showed the optimized 30% Fe CN/ZIS achieved the best photoreduction of Cr(VI)performance within a wide p H range, which was 9.5 times and 700 times higher than that of pure ZnIn_(2)S_(4)and 30% Fe CN(Fe doped g-C_(3)N_(4)). This is due to the intense synergy between the Fe-Nxbond and close interface contact produces a high-speed charge transfer channel, thus significantly improving the efficiency of optical carrier separation and migration. Meanwhile, UV-vis diffuse reflection spectra and photoluminescence spectroscopy showed that iron doping significantly narrowed the bandgap of gC_(3)N_(4), preventing electron-hole pair recombination. Further, the microstructures and charge separation properties were analyzed by scanning electron microscope, Photoluminescence Spectroscopy and timeresolved photoluminescence, which revealed the structure-activity relationship of composite structure and the synergistic mechanism of each functional component. This research should provide a viable technique for creating composites with high photocatalytic activity for the treatment of chromium-containing wastewater.