Strong Interfacial Interaction Research Articles

Interfacial Engineering by Self‐Assembled Monolayer for High‐Performance Sb2S3 Solar Cells

AbstractAntimony chalcogenides films and devices have drawn much attention in recent years because of their notable advantages. Unfortunately, the performance of Sb‐based solar cells is still underdeveloped compared to the theoretical value, which is closely related to charge carrier separation and transfer, highlighting the importance of enhancing the interface quality. In this work, an interfacial engineering by utilizing a self‐assembled monolayer (SAM) of MeO‐2PACz as an interface layer between the Sb2S3 and Spiro‐OMeTAD is developed to assist hole transport. The strong interface interaction between Sb2S3 and MeO‐2PACz is systematically investigated by Raman, X‐ray photoelectron spectroscopy (XPS) measurements, and Density functional theory (DFT) calculations. Through such interfacial engineering, a more uniform surface potential, bigger built‐in potential, better energy‐level match as well as outstanding photoelectric properties are achieved. Finally, the champion power conversion efficiency (PCE = 8.06%) of Sb2S3 solar cells with SAMs is inspiringly enhanced by >13%. It is expected that this effort will bring fresh insights and strategies for improving the performance of Sb‐based solar devices.

A novel and convenient zeolite modification strategy for enhancing the fire resistance of epoxy resin

The preparation process of new environmentally friendly flame retardants to endow epoxy resin (EP) with excellent flame retardancy and mechanical properties remains a challenging task. In this study, a novel Zeolite@DPA-Cu flame retardant was designed and prepared by a simple and environmentally friendly aqueous preparation process using zeolite, copper sulfate and diphenylphosphonic acid as main raw materials. As expected, Zeolite@DPA-Cu significantly improved the flame retardancy and mechanical properties of EP composites. The results showed that the LOI and UL-94 grade of the EP/5 wt% Zeolite@DPA-Cu composite reached 32.4 % and V-0 rating, respectively. The synergistic effect of the physical barrier, free radical capture and catalytic char formation of Zeolite@DPA-Cu significantly improved the flame retardancy of EP. In addition, due to the strong interfacial interaction between Zeolite@DPA-Cu and EP, the tensile strength and elongation at break of the EP were increased to 57.92 MPa and 4.7 %, respectively. Generally, this study proposed a modification strategy that takes into account both flame retardancy and mechanical properties, which is extremely important for the practical application of EP flame retardant materials.

Durable and highly signal-stable pressure sensors prepared by sequential thiol-acrylate click reactions

Pressure sensors are an important part of the Internet of Things (IoT) and human–machine interaction (HMI), and their signal stability and durability are greatly affected by the interfacial interaction between the substrate and the conductive layer. Herein, a pressure sensor prepared by sequential radical-mediated thiol-acrylate click reactions is reported. In first click reaction, the porous substrate polyHIPE-SH with inherently thiols is fabricated. Those thiols give us second chance to chemically bridge carboxylic carbon nanotubes (CNT)/polyethylene glycol diacrylate (PEGDA) conductive coating to the substrate using the click reaction, with 21.5 % of the thiols on the substrate involved in the reaction. As expected, the obtained pressure-sensitive material CNT/PEGDA@polyHIPE-SH has a strong interfacial interaction between the substrate and the conductive layer, thus ensuring the good signal stability and durability. The sensor also has a sensitivity of up to −6.45 % kPa−1 and a wide response range from 0 to 400 kPa. Furthermore, the sensors are used as input devices to realize multi-mode HMI, and high-accuracy object recognition at low sensor densities via a convolutional neural network based deep learning model.

In situ crosslinking of silica aerogel with reactive carbon fiber for high mechanical property, thermal insulation and superhydrophobicity

In this study, a novel silicon hydroxyl groups decorated long carbon chain grafted carbon fiber was synthesized, and a facile fabrication method was developed to produce reactive carbon fiber-silica aerogel composite with chemical crosslinking structure. Scanning electron microscopy images showed that silica aerogel matrix is wrapped on the surface of reactive carbon fibers. The reactive carbon fibers facilitated obstacle in shrinkage, and aerogel composites exhibited microporous behavior with average diameter of about 1.8 nm. Fourier-transform infrared and X-ray photoelectron spectroscopy confirmed the strong interfacial interaction between reactive carbon fibers and silica matrix. The modification mechanism of silicon hydroxyl groups decorated long carbon chain grafted carbon fiber, and the chemical crosslinking in aerogel composite were proposed. The reactive carbon fiber-silica aerogel composites synthesized in this work had been proved to have low density, excellent mechanical property, good tailoring performance, improved thermal stability, low thermal conductivity, high flame retardancy, high thermal insulation property, and superhydrophilicity. Hence, this work provided a theoretical basis for improving the performance and expanding the application of silica aerogel.

II-Scheme Heterojunction Frameworks Based on Covalent Organic Frameworks and HKUST-1 for Boosting Photocatalytic Hydrogen Evolution.

Covalent organic frameworks (COFs) are one type of promising polymer semiconductors in solar-driven hydrogen production, but majority of COFs-based photocatalytic systems show low photocatalytic efficiency owing to lack of metal active sites. Herein, we reported II-Scheme heterojunction frameworks based on COF (TpPa-1) and metal-organic framework (HKUST-1) for highly efficient hydrogen production. The coordination bonding directed self-assembly of HKUST-1 on the surface of TpPa-1 endows the heterojunction frameworks (HKUST-1/TpPa-1) with strong interface interaction, optimized electronic structures and abundant redox active sites, thus remarkably boosting photocatalytic hydrogen evolution. The hydrogen evolution rate for optimal HKUST-1/TpPa-1 is as high as 10.50 mmol g-1 h-1, which is significantly enhanced when compared with that of their physical mixture (4.13 mmol g-1 h-1), TpPa-1 (0.013 mmol g-1 h-1) and Pt-based counterpart (6.70mmol g-1 h-1). This work offers a facile approach to the construction of noble-metal-free II-Scheme heterojunctions based on framework materials for efficient solar energy conversion.

Platinum-nickel nanocrystals anchored on heteroatom-functionalized Ti3-xC2Ty MXene 3D porous architecture for electrocatalytic hydrogen evolution in alkaline electrolytes

BackgroundRational design and construction of efficient electrocatalysts are crucial for enhancing the activity and stability of the hydrogen evolution reaction (HER) in alkaline electrolytes. MethodsHerein, heteroatom (phosphorus and sulfur)-functionalized and self-adapting Ti3+ species defect decorated Ti3-xC2Ty MXene (PS-TCT) with 3D porous architecture for anchoring platinum-nickel (PtNi) bimetallic nanocrystals for alkaline electrocatalytic HER. Experimental and theoretical studies have shown that the heteroatoms delicately modulated the electronic configuration of MXene to optimize the adsorption capacity of the reaction intermediates. The 3D porous spatial configuration of PS-TCT with abundant Ti3+ species defect endowed an efficient channel for charge transfer and sufficient catalytically active sites, thus facilitating fast dynamics and long-term stability. Additionally, the strong bimetal-substrate interfacial interaction (Pt-S bonding) between PtNi and PS-TCT established an electron directional transport channel, thus achieving valid and stable interfacial electron transport. Significant findingsConsequently, the optimized PtNi@PS-TCT nanohybrids showed remarkable catalytic activity with low overpotentials of 56.1 mV at 10 mA cm−2 and impressive Tafel slope of 81 mV dec−1 for HER in alkaline electrolytes (1.0 M KOH), while exhibiting outstanding electrochemical stability. This work offers a constructive route for precisely constructing high-performance multifunctional composite electrocatalysts.

Investigating competition of strong interfacial interaction and chain scission in PBAT/EVOH/GO composite by rheological measurements

Investigating competition of strong interfacial interaction and chain scission in PBAT/EVOH/GO composite by rheological measurements

Alleviating Ni electron depletion of Ni phthalocyanine by doping electron-deficient boron in CNTs support for enhanced CO2 electroreduction

Dispersed nickel phthalocyanine (NiPc) on carbon nanotubes (CNTs) is the promising electrocatalyst for carbon dioxide reduction (CO2RR), but the strong interfacial electron interaction causes Ni electron depletion, limiting CO2RR performance. Herein, engineering the heteroatom doping in CNTs is proposed to alleviate electron depletion of Ni sites toward effective CO2RR. Boron heteroatoms induce electron-enriched Ni sites in NiPc/B-CNTs compared to phosphorus, nitrogen, and fluorine doped catalysts, resulting in superior CO2RR performance. Impressively, the NiPc/B-CNTs presents high CO Faraday efficiency (FECO) of >98 % from −20 to −80 mA cm−2 and excellent stability up to 37 h with sustained FECO of > 90 % in neutral electrolyte. Theoretical and experimental investigation reveals that implanting B heteroatoms alleviates Ni electron depletion via weakening electron transfer from NiPc to CNTs and thus reduces reaction barrier of *COOH formation, facilitating CO2RR. This study highlights importance of modifying carbon substrate in development of supported molecular catalysts for practical applications.

Influence of graphene oxide additives on the NF separation of triazine-based H2S scavenging compounds using advanced membrane technology

This work proposes an innovative approach for the membrane separation of spent and unspent H2S scavengers (SUS) derived from the application of MEA-triazine in offshore oil and gas production. Modified nanofiltration membranes were fabricated by incorporating graphene oxide (GO) and polyvinyl alcohol (PVA) into a thin film composite (TFC) to obtain a thin film nanocomposite (TFN) with enhanced permeability. In addition, various immobilization strategies for GO were investigated. The performance of the membranes and the effect of the GO loading were evaluated in terms of permeability, fouling propensity, and rejection of key components of the SUS, i.e., MEA-triazine (unspent scavenger), dithiazine (spent scavenger), and monoethanolamine, operating on a sample of SUS wastewater obtained from an offshore oil and gas platform. Various characterization techniques, such as contact angle, FTIR, XRD, SEM, TGA, and AFM, were employed to evaluate the structure, composition, and hydrophilicity of the membrane. The results show a remarkable increase in permeability (from 0.22 Lm-2 h−1 bar−1 for the TFC to 5.8 Lm-2 h−1 bar−1 for the TFN membranes), due to the enhanced hydrophilicity from GO incorporation. The strong interfacial interaction between GO and PVA within the TFN membrane results in negligible nanofiller leaching. The incorporation of GO moderately increases the rejection of the unspent scavenger (63%–73%, 62%–79%, 62%–80%, and 68%–76%), while drastically increasing the rejection of the spent scavenger, which is approximately null for the TFC membrane without GO and increases up to 58% in the TFN membrane with GO. Therefore, while the proposed membranes cannot be used for the selective separation of the unspent form the spent scavenger, they can achieve substantial recovery of all the key components contained in the SUS to avoid their discharge into the sea.

Enhancing interfacial thermal conductivity of copper-carbon nanotube array composite via metallic bonding: Molecular dynamics simulations

In this work, a novel strategy for improving the interface thermal conductivity (ITC) between the vertically aligned carbon nanotube (VACNT) arrays and copper was proposed and verified using the non-equilibrium molecular dynamics (NEMD) simulations. The introduced metal elements (Ag, Al, Ti, and Ni) enhanced the ITC of the Cu-VACNT interface region via a strong adhesive force. Notably, different from the physisorption between Ag/Al elements and VACNT, a strong interfacial interaction was introduced between the chemically bonded Ni/Ti and VACNT. In addition, the matching degree of the phonon state density (PDOS) at the Ni-VACNT interface increases with increasing contact area between the Ni atoms and Cu substrate. Nevertheless, it was found that over-strong interfacial interaction between the VACNT and Ti element deteriorates the matching degree of high-frequency phonons at the Ti-VACNT interface. These findings offer valuable criteria for designing and selecting materials to enhance interfacial thermal conduction in composite electronic packaging.

Lab on the Microneedles: A Wearable Metal-organic Frameworks-Based Sensor for Visual Monitoring of Stress Hormone.

Abnormal secretion and dysrhythmias of cortisol (CORT) are associated with various diseases such as sleep disorders, depression, and chronic fatigue. Wearable devices are a cutting-edge technology for point-of-care detection and dynamic monitoring of CORT with inspiring convenience. Herein, we developed a minimally invasive skin-worn device with the advanced integration of both interstitial fluid (ISF) sampling and target molecule sensing for simultaneous detection of CORT via a microneedle-based sensor with high sensitivity, excellent efficiency, and outstanding reproducibility. In the microneedle patch, swellable hydrogel was employed as the adsorption matrix for ISF extraction. Meanwhile, europium metal-organic frameworks (Eu-MOF) wrapped in the matrix played a vital role in CORT recognition and quantitative analysis. The wearable and label-free Eu-MOF-loaded microneedle patch exhibited high sensitivity in CORT detection with the detection limit reaching 10-9 M and excellent selectivity. Molecular dynamics simulation-driven mechanism exploration revealed that the strong interface interaction promoted fluorescence quenching of Eu-MOF. Moreover, in vitro and in vivo investigation confirmed the feasibility and reliability of the sensing method, and excellent biocompatibility was validated. Overall, a sensitive approach based on the wearable Eu-MOF microneedle (MN) patch was established for the simultaneous detection of CORT via visible fluorescence quenching with exciting clinical-translational ability.

Supramolecularly Connected Armor-like Nanostructure Enables Mechanically Robust Radiative Cooling Materials.

Passive daytime radiative cooling (PDRC) is a promising practice to realize sustainable thermal management with no energy and resources consumption. However, there remains a challenge of simultaneously integrating desired solar reflectivity, environmental durability, and mechanical robustness for polymeric composites with nanophotonic structures. Herein, inspired by a classical armor shell of a pangolin, we adopt a generic design strategy that harnesses supramolecular bonds between the TiO2-decorated mica microplates and cellulose nanofibers to collectively produce strong interfacial interactions for fabricating interlayer nanostructured PDRC materials. Owing to the strong light scattering excited by hierarchical nanophotonic structures, the bioinspired film demonstrates a desired reflectivity (92%) and emissivity (91%) and an excellent temperature drop of 10 °C under direct sunlight. Notably, the film guarantees high strength (41.7 MPa), toughness (10.4 MJ m-3), and excellent environmental durability. This strategy provides possibilities in designing polymeric PDRC materials, further establishing a blueprint for other functional applications like soft robots, wearable devices, etc.

Insight into the relationship between interfacial structure and thermal conductivity in epoxy resin/Al2O3 composite

AbstractThe relationship between interfacial structure and thermal conductivity in epoxy resin/Al2O3 composite is important but is still elusive. Here, we illuminate this issue by investigating the role of four silane coupling agents in thermal conductivity for epoxy resin/Al2O3 composites. The results show that 3‐glycidoxypropyltrimethoxysilane (KH560) is the best silane coupling agent to modify Al2O3, resulting in the lowest viscosity and the highest thermal conductivity of the epoxy resin/Al2O3‐KH560 composite compared with alternative systems. This is attributed to the strong interfacial interaction between Al2O3‐KH560 and epoxy resin, as confirmed by the Fowkes model and broadband dielectric spectroscopy. The interfacial thermal resistance between the epoxy resin and Al2O3 is also quantitatively measured via a photothermal radiometry technique. The epoxy resin/Al2O3‐KH560 also has the lowest interfacial thermal resistance (1.50 ± 0.02 × 10−6 m2 K W−1), compared with the other three systems. This study advances the understanding of the relationship between interfacial structure and thermal conductivity in polymer composites.Highlights The relationship between interfacial structure and thermal conductivity in epoxy resin/Al2O3 composite is understood. The interfacial structure is characterized by broadband dielectric spectroscopy. The interfacial thermal resistance is quantitatively measured via a photothermal radiometry technique.

Thermal‐mechanical properties of bamboo charcoal/recycled low‐density polyethylene composites

AbstractBamboo fiber has garnered considerable attention owing to its high specific strength and renewability. However, the hydrophilic nature of the material must be carefully managed to create a bamboo composite with usable thermal‐mechanical properties. Herein, the NaOH‐treated bamboo fiber (particle size ≤200 μm) was used to produce bamboo charcoal (BC). Then, recycled low‐density polyethylene containing BC composites was fabricated by varying the BC composition (between 2 and 8 wt%). Effects of different BC wt% in the BC/recycled low‐density polyethylene composites (denoted as xBCPE, where x indicates BC wt% in the composites) were analyzed for tensile strength, morphology, and thermal properties. In addition, the water absorption capacities of the BCPE composites were compared. These xBCPE composites showed excellent thermal stability and low water absorption properties. Therefore, they are potential candidate materials for electrical device packaging with partial degradability.Highlights Bamboo charcoal (BC) was prepared via low‐temperature pyrolysis of alkaline‐treated bamboo fiber. BC displayed strong interfacial interaction with recycled low‐density polyethylene. Proportion of BC on the composite properties was investigated and furnished. The xBCPE composites demonstrate low water absorption and excellent thermal stability. The reinforced composite (4BCPE) shows great promise as a functional material.

Over-Reduced Core–Shell Au@CoOx-Co with Strong Interfacial Interactions for Photoassisted Peroxymonosulfate Activation

Over-Reduced Core–Shell Au@CoO_<i>x</i>-Co with Strong Interfacial Interactions for Photoassisted Peroxymonosulfate Activation

Molten salt induced strong interaction between Co3O4 and montmorillonite for the promoted peroxymonosulfate activation toward tetracycline degradation

Cobalt-based materials exhibit great premises for activating peroxymonosulfate (PMS) toward water remediation. Generally, active Co species are anchored on the surface of supports to improve the utilization efficiency, yet the stability of the catalyst is difficult to resolve due to the weak interaction between the active species and the support. Herein, a molten salt method is employed to reinforce the interfacial interaction between Co3O4 and montmorillonite (Mt) support. The use of molten Na3PO4 can mitigate the dehydroxylation process of Mt, and thus the electronic structure of Co3O4 NPs can be regulated by the surface hydroxyl species more efficiently. Consequently, the prepared Co3O4/Mt displays an enhanced CoII/CoIII ratio, and the degradation of tetracycline (TC) could reach 99% in 7 min by the PMS-based advanced oxidation process. Meanwhile, the TC removal efficiency can still reach 96% after 8 cycles, and the Co ion leaching is over 10 times lower as compared with the catalyst prepared not using the molten salt. This study highlights the significance of the molten salt method for enhancing the strong interfacial interaction, which is crucial to regulating the nature of supported catalysts, and provide satisfactory Co-based catalyst for PMS activation toward TC degradation.

Fabrication of sodium lignosulfonate/waterborne polyurethane composites with high biological content to enhance mechanical properties and UV resistance

The conversion of sodium lignosulfonate (SL) into high-value functional materials remains challenging. Hereon, a bio-based waterborne polyurethane (WPU) was synthesized using castor oil and isophorone diisocyanate as the raw materials. SL was used as a functional filler to prepare transparent or translucent composites of sodium lignosulfonate/waterborne polyurethane with good properties through physical blending method. The influence of varying SL contents on the performance of composite emulsions and films were studied. The results indicated that the composite derived from bio-based materials had an occupancy rate of 89.5 %, and all composite emulsions exhibited outstanding storage stability. Interestingly, the addition of sodium lignosulfonate greatly improved the mechanical properties and heat resistance due to the strong interfacial interaction between WPUs and SL molecular chains. Furthermore, the composite film could achieve complete UV shielding performance when the sodium lignosulfonate content reached 9 wt %. This work had significantly expanded the range of high-value-added applications for lignin and potential prospects for its use in the field of sunscreen coatings.

Crystalline Phase Engineering to Modulate the Interfacial Interaction of the Ruthenium/Molybdenum Carbide for Acidic Hydrogen Evolution.

Ruthenium (Ru) is an ideal substitute to commercial Pt/C for the acidic hydrogen evolution reaction (HER), but it still suffers from undesirable activity due to the strong adsorption free energy of H* (ΔGH*). Herein, we propose crystalline phase engineering by loading Ru clusters on precisely prepared cubic and hexagonal molybdenum carbide (α-MoC/β-Mo2C) supports to modulate the interfacial interactions and achieve high HER activity. Advanced spectroscopies demonstrate that Ru on β-Mo2C shows a lower valence state and withdraws more electrons from the support than that of Ru on α-MoC, indicative of a strong interfacial interaction. Density functional theory reveals that the ΔGH* of Ru/β-Mo2C approaches 0 eV, illuminating an enhancement mechanism at the Ru/β-Mo2C interface. The resultant Ru/β-Mo2C exhibits an encouraging performance in a proton exchange membrane water electrolyzer with a low cell voltage (1.58 V@ 1.0 A cm-2) and long stability (500 h@ 1.0 A cm-2).

Boosting catalytic oxidation of propane over CeO2-supported Co3O4 catalyst with strong interfacial interaction and electron transfer

Tuning the nanoparticle-support interaction can optimize the catalytic performance of supported metal oxide catalysts for VOCs removal. Herein, a series of Co3O4/CeO2 catalysts with different strengths of interfacial interaction and electron transfer were successfully constructed via various modified wetness impregnation procedures. With the introduction of ammonium hydroxide, citric acid or H2 pretreatment, a stronger interfacial interaction and electron transfer were achieved due to the highly Co3O4 dispersion and CeO2 surface reconstruction. The modified-synthesis Co3O4/CeO2 catalysts, particularly Co3O4/CeO2-CA (citric acid), demonstrated superior catalytic activity (T90 = 296 °C, TOF = 0.337 × 10−3 s−1) and stability for propane oxidation as compared to typical wetness impregnation Co3O4/CeO2-DI (T90 = 314 °C, TOF = 0.121 × 10−3 s−1). Through systematic characterizations and DFT calculation, the strong interfacial interaction and abundant reactive oxygen species facilitate the adsorption and activation of C3H8 and O2 on the catalyst surface, which further promote the intermediates (carbonate/carboxyl species) transformation. These findings highlight interfacial mechanism to catalytic performance optimization of supported metal oxides.

Mesoscale smoothed particle hydrodynamics simulation of seizure and flash temperature for dry friction of elastoplastic solids in a newly developed model

This study developed a simulation model using a smoothed particle hydrodynamics (SPH) method targeted to seizure process at the mesoscale. The mechanisms of wear, adhesion, and heat generation leading to seizure at the mesoscale were modelized without assumptions or theories based on empirical rules. In particular, we targeted on flash temperature during seizure process, which is difficult to measure directly in experiment and has not been simulated without using friction theory.Our model consisted of both a macroscopic elastoplastic consideration and a microscopic interfacial interaction consideration, and the heat generation scheme that 90% of the plastic strain energy is converted to heat energy were adopted in the model. The simulation demonstrated the seizure process in which the contact state is maintained by the strong interfacial interaction as the plastic strain progresses and the temperature rapidly rises. The flash temperature by the simulation provided a reasonable quantitative match at order level to a temperature estimated by substituting true contact area and interfacial heat flux obtained by the simulation into a theoretical formula of flash temperature.