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The adsorption mechanisms of hazardous gas molecules such as NH3, H2S and SO2 on sepiolite have not yet been elucidated. Therefore, molecular dynamics (MD) simulations were employed to investigate the adsorption behaviour of sepiolite towards NH3, H2S and SO2. A calculation model for sepiolite containing structural and zeolitic water molecules was constructed in this study. The adsorption sites and molecular configurations of the hazardous gases in the sepiolite channels were studied. The radial distribution function was employed to evaluate the interactions between the gas molecules and sepiolite. The results show that the order of adsorption capacity of sepiolite for the gases is as follows: SO2 > H2S > NH3. These three types of gas molecules absorbed in the channel nanopores of sepiolite exhibit different atomic configurations. The diffusion coefficients of the gas molecules in the channels decreased in the following order: NH3 > H2S > SO2. In addition, the diffusion coefficients were affected significantly by the ratio of the number of gas/water molecules. This study provides new perspectives for understanding the molecular processes responsible for the adsorption properties of sepiolite.

The mechanical measurements of nanostructures are crucial to the development and processing of novel nanodevices. In this study, TiO2 nanotubes were synthesised using an electrospinning method combined with subsequent heat treatment. A simple experimental method is established to measure the elastic modulus of a single nanotube based on atomic force microscopy (AFM) technology. Subsequently, the finite element method (FEM) is employed to evaluate the effect of the elastic modulus of TiO2 and dimensional size on the mechanical behaviours of the TiO2 nanotubes. The results show that, by combining AFM with FEM technology, the mechanical behaviour of a single TiO2 nanotube can be predicted efficiently in the linear elastic region.

Developing highly active catalysts for hydrogen evolution reaction is vital for large-scale and efficient production of hydrogen through water splitting. In this study, we reported scale-up TiO2/LaFeO3 composite catalysts with multiple heterojunctions synthesized via facile solid-phase reaction and investigated their hydrogen evolution reaction (HER) performance in both acidic and alkaline solutions. To be excited, under AM1.5 simulated sunlight irradiation, the working electrode decorated by TiO2/LaFeO3 presents a higher current density with 10 mV/cm2 at 0.55 V in a 0.5 M H2SO4 solution, suppressing the corresponding performance with the occasion of pure electrocatalysis. Importantly, the hydrogen evolution efficiency can reach 7.62 mmol h−1 cm−2, overwhelming approximately 5.3 times higher than that of commercial P25 (1.43 mmol h−1 cm−2) with exceptional stability via imposing simulated sunlight and a bias of 500 mV. Therefore, such excellent catalysts could serve as an alternative to reach remarkable HER performance via fossil fuels free technology, potentially making contribution toward the goal of global “carbon neutral” by 2050.

To accommodate volume change of sulfur particles, confine lithium polysulfides (LiPSs) within conductive matrix, as well as accelerate transference of electrons/ions, the sulfur@reduced graphene oxide (S@RGO) yolk-shell particles wrapped by polyaniline (PANI) nanowires were prepared in this work. Meanwhile, PANI nanowires are synthesized by in situ polymerization of aniline monomers. Importantly, many nanoscale holes are generated on the RGO nanosheets forming three-dimensional channels for ion transportation within the obtained composite material. LiPSs can be firmly confined in the composite material by the polar oxygen-containing groups on the surface of the RGO shells and the protonated nitrogen-containing groups on the PANI nanowires. Benefiting from the unique structure, the S@RGO/PANI particles exhibit an improved electrochemical performance. It can deliver an initial capacity of 1021 mAh·g−1 at 0.1C rate and a high initial coulombic efficiency up to 95.4%. Even at 2.0C rate, a discharge capacity of 501 mAh·g−1 can be retained after 500 cycles. Results indicate that the S@RGO/PANI can be promisingly exploited as a kind of high-energy density cathode material for rechargeable lithium batteries.

Highly aligned polyimide/graphene oxide (PI/GO) nanofibers were fabricated by using the electrospinning method. As a separator for Li-ion batteries, the PI/GO nanofibers show excellent thermal stability, good wettability toward organic liquid electrolytes and superior electrochemical performance compared to raw PI and commercial battery separators. The GO nanosheets not only greatly enhance the mechanical strength of the PI matrix, but also increase the resistance to Li dendrites.

Due to the advantages of high energy density and improved safety properties, Li metal batteries with gel polymer electrolyte (GPE) have drawn much attention in recent years. Herein, a novel gel thermoplastic polyurethane (TPU) electrolyte filled with ultrafine hydrophilic–lipophilic TiO2 nanoparticles was successfully prepared by using a phase separation technology. The gel electrolyte can protect the battery against the leakage of liquid electrolyte by means of its strong interaction with Li+ and solvents. This kind of GPE shows an ionic conductivity of 1.59 mS cm−1 and an electrochemical window of 4.3 V (vs. Li/Li+) at room temperature. Robust TiO2 nanoparticles embedded into TPU matrix can effectively block dendrite puncture and, besides, greatly improve the thermal stability of GPE. The cycling performance, rate capability and mechanical properties guarantee the reliability of the as-prepared GPE in Li-ion batteries.

CdS nano-photocatalysts hold a great promise for the photocatalytic hydrogen evolution; however, their practical application is greatly hampered by poor activity and stability due to the recombination of the photogenerated charge carriers and photocorrosion phenomena. Herein, we report a novel 3-dimensional CdS@UiO-66 nanostructures obtained by a facile solvent-free approach; with a step-by-step procedure, the core/shell configuration provided a suitable unit in size to easily equip defect-rich MoS2 nanosheets. The UiO-66 Zr-MOFs used as a porous container to promote the dispersion of CdS nanoparticles, resulting to the increasement of active sites for photocatalytic reaction. The further enhanced photocatalytic activity for MoS2 hybrid CdS@UiO-66 originated from the manufactured defect on the exposed edges of MoS2 nanosheets, which was produced by adjusting the S/Mo ratio. UiO-66 did not only provide extensive migration routes over photogenerated electrons, more importantly, it created ample time and sites for accelerating consumption of the isolated photogenerated holes with sacrificial agent, resulting in alleviating photocorrosion reaction. The photocatalytic efficiency and photostability were simultaneously promoted. This work highlights the potential application of core/shell configuration in photocatalytic hydrogen evolution. CdS@UiO-66 type composite photocatalyst was obtained in the condition of solvent-free assembling at room temperature. The defect-rich MoS2 nanosheets were felicitously equipped on the core/shell configuration. The obtained defect MoS2 hybrid CdS@UiO-66 composite material exhibits a high and stable hydrogen production rate due to their synergistic effect.

Here lithium acetate modified PU/graphene composites were prepared from a simple electrospun method. The electrochemical properties, thermal stability, and mechanical properties of polyurethane (PU) separator have been improved remarkably by the addition of lithium acetate and graphene. The composite separator can maintain the dimension size even after being treated at 170°C for 1 h. High ionic conductivity of 2.47 mS·cm -1 can be reached. The results show that the as-prepared lithium acetate modified PU/graphene separator is a promising candidate for commercial polyolefin separators.

Electrospun PAN/PVdF-HFP membranes have the potential to be used as separators for Li-ion batteries owing to their good mechanical properties and high chemical stability. However, the application of PAN/PVdF-HFP separators has been hampered by their poor electrochemical performances. In this study, semi-aligned PAN/PVdF-HFP nanofiber separators have been fabricated by an electrospinning technology. Sepiolite and ZIF-67 co-modification was employed to enhance the physical properties of the PAN/PVdF-HFP separators. The test cells with the as-prepared composite separator showed better electrochemical performance than the commercial and raw PAN/PVdF-HFP separators.

Coastal asphalt pavements are highly susceptible to sea salt erosion, which leads to a significant decrease in road performance and durability. However, the interface micro-adhesion mechanism of the asphalt-aggregate composites under chloride ion erosion is still not fully understood. Herein, using the silica microsphere Atomic Force Microscopy (AFM) modified tip and asphalt sample with chloride ions as a surface, we report the effect mechanism of chloride ion erosion on the interface adhesion behavior of asphalt-silica composites by AFM from the atomistic scale. The chloride ion erosion mechanism was further supported by molecular dynamics (MD) simulations. Due to the erosion effect of chloride ions, the structure evolution of the asphalt film surface will occur, and the weak adhesion gradient zone will be formed on the surface of the asphalt film. The concentration effect of chloride ions accelerates the formation of adhesion gradient zones, which are unstable and evolve over erosion time. Due to the presence of these adhesion gradient zones, water molecules will more easily penetrate the asphalt membrane and enter the asphalt-silica interface through adsorption and diffusion, thereby weakening the interface adhesion ability between the asphalt and the aggregate. Furthermore, the distribution and diffusion of asphalt fractions on the aggregate surface also affect the adhesion behavior evolution of asphalt-silica composites induced by chloride ion erosion. The evolution in the spatial distribution of fractions may be related to the formation of interfacial adhesion gradient zones. This study outcome has important theoretical significance for promoting the sustainability of asphalt pavements and for guiding pavement deicing.

As an organic material, asphalt is vulnerable to ultraviolet (UV) irradiation. The effect of UV aging on physical properties has been intensively studied. In this study, large ZnO/C nanosheets were employed to shield asphalt from UV irradiation and delay the deterioration of its natural properties. The evolution of the morphology and adhesion properties of the ZnO/C nanosheet-modified asphalt material at the nanoscale was characterized by atomic force microscopy (AFM). The results show that the ZnO/C nanosheet-modified asphalt behaves differently from raw asphalt. The increase in the number of flaws can be suppressed by the addition of ZnO/C nanosheets, and the change in the adhesion properties caused by UV irradiation can also be hampered.

Li-dendrite resistant and high-performance separators are effective ways to solve the safety problem in advanced Li storage. Several intrinsic factors, including low thermal stability, low porosity and poor wettability, restrict the application of organic separators in safe Li storage. Inorganic porous membranes are promising candidates for commercial polyolefin-based separators due to their excellent thermal stability and good compatibility with organic electrolytes. In this study, we develop a flexible, Li-dendrite resistant and binder-free inorganic separator for safe Li storage based on ultralong Na2Ti3O7 nanobelts. The high thermal stability of Na2Ti3O7 nanobelts enables the separators to preserve their structural integrity up to 1000 °C. In addition, the as-prepared separators exhibit excellent flexibility, high porosity, and high cycling stability, which guarantee both the safety and high performance of the batteries.

Natural sepiolite mineral has been commonly used in the industry because of its unique structure and physical properties. In this paper, we fabricated sepiolite-based battery separators by simple and inexpensive electrospinning technology. The as-prepared sepiolite-based separators show high thermal stability and excellent electrochemical properties, making them a superior candidate for long-term operation under thermally stressful conditions. Our research indicates that sepiolite can be employed to improve the reliability and electrochemical performance of polymer-based separators.

Recently we found that multi-walled carbon nanotube (MWCNT) exposure alters the mRNA levels of endoplasmic reticulum (ER) stress/autophagic genes, but the impact of biological molecules on this response is unclear. Herein, we compared the different actions of carboxylated MWCNTs (c-MWCNTs) pre-incubated with bovine serum albumin (BSA) or BSA-complexed free fatty acid (denoted as FFA) on macrophages derived from THP-1 monocytes (denoted as THP-1 macrophages). C-MWCNTs exhibited increased diameter and hydrodynamic size as well as decreased absolute zeta potential value after pre-incubation with BSA or FFA, which suggested a coating effect. Cytotoxicity or oxidative stress were not significantly induced after exposure to BSA- or FFA-coated c-MWCNTs. BSA-pre-incubated c-MWCNTs significantly enhanced the expression of the ER stress gene, DDIT3 and the autophagic genes, ATG5, BECN1, and PLIN2, but the mRNA levels of these genes was significantly decreased by FFA-pre-incubated c-MWCNTs. FFA-pre-incubated c-MWCNTs induced significantly higher lipid accumulation and interleukin-6 (IL-6) protein level compared with BSA-pre-incubated c-MWCNTs, which suggested that FFA-pre-incubated c-MWCNTs may more effectively induce the formation of macrophage foam cells. Collectively, our data indicated that pre-incubation with FFA may influence c-MWCNT-induced ER stress/autophagic gene expression and foam cell formation in THP-1 macrophages.

Polyurethane (PU) has been intensively studied as a promising separator material for Li-ion batteries (LIBs). However, poor dimensional stability and low liquid-electrolyte wettability of pure PU separator restrict its application in LIBs. Here polyvinyl pyrrolidone (PVP) and graphene oxide were employed to enhance the thermal stability, mechanical performance and liquid-electrolyte compatibility of PU separator. High anodic stability above 5.25 V was reached in PU/PVP/GO separator, fully compatible with the high-voltage cathode materials. The electrochemical characterization indicates PU/PVP/GO membrane is a promising separator for advanced LIBs.

As a potential anode material for Li-ion batteries, ZnO has been intensively studied owing to its high theoretical capacity and low cost. However, low electronic conductivity restricted the application of ZnO in Li-ion batteries. It has been well recognized that morphology-controlled ZnO nanostructures can serve as high-performance anode materials. Here carbon-decorated flower-like ZnO nanostructures have been synthesized by microwave-assisted hydrothermal reactions. The carbon decoration on the flower-like ZnO surface not only suppresses the growth of ZnO crystals but also increases the electronic conductivity of ZnO. The results indicate that the nanocarbon-decorated flower-like ZnO materials can be employed as high-performance anode materials for advanced Li storage.

Summary Solar-driven photochemical hydrogen evolution is a promising route to sustainable hydrogen fuel production. Large-scale preparation of highly active photocatalysts using elementally abundant and less-expensive materials is urgently required for widespread practical application. Here, we report a highly efficient and low-cost TiO2/MgTiO3/C heterostructure photocatalyst for photochemical water splitting, which was synthesized on gram scale via a facile mechanochemical method. The heterostructure and carbon sensitization offer excellent photoconversion efficiency as well as good photostability. Under irradiation of one AM 1.5G sunlight, the optimal TiO2/MgTiO3/C photocatalyst can show a great solar-driven hydrogen evolution rate (33.3 mmol·h−1·g−1), which is much higher than the best yields ever reported for MgTiO3-related photocatalysts or pure TiO2 (P-25). We hope this work will attract more attention to inspire further work by others for the development of low-cost, efficient, and robust photocatalysts for producing hydrogen in artificial photosynthetic systems., Graphical Abstract, Highlights • The synthetic process does not involve any organic solvents and hazardous by-products • The optimal sample shows a H2 evolution rate of 33.3 mmol·h−1·g−1 under one sunlight • The optimal sample keeps a H2 evolution rate of 1.46 mmol·h−1·g−1 under visible light • Uniform carbon layer was ingeniously deposited on the surface of photocatalysts, Catalysis; Energy Resources; Chemical Synthesis

Asphalt aging is one of the most severe threats to the asphalt pavement durability and rejuvenation with cooking oil can help to resolve this issue. Currently, the influence of aging/rejuvenation on the bonding performance of asphalt binder has not been fully understood. This study aims to unveil the influence of aging/rejuvenation on the adhesion performance under both micro and macro scale tests. Three type asphalt binders were examined in this study, including the original, aged and rejuvenated samples. The atomic force microscope (AFM) was first applied to examine the surface morphology and adhesion performance of the three type asphalt samples. It is found that the aging effect can increase the adhesion between asphalt binder and silica particles and the adhesion force can be further enhanced through rejuvenation. Then the three-point bending was further conducted to examine adhesion performance at the macroscale, and the obtained results are in accordance with those obtained at the microscale. However, the slant shear test indicated the shear bond strength can be reduced due to the rejuvenation with vegetable oil, which can be generated due to the lubrication effect of the oil. The results in this study can help to better understand the influence of aging and rejuvenation on the bond performance between asphalt binder and mineral aggregate.

In catalysis, tuning the structural composition of the metal alloy is known as an efficient way to optimize the catalytic activity. This work presents the synthesis of compositional segregated six-armed PtCu nanostars via a facile solvothermal method and their distinct composition-structure-dependent performances in electrooxidation processes. The alloy is shown to have a unique six arms with a Cu-rich dodecahedral core, mainly composed of {110} facets and exhibit superior catalytic activity toward alcohols electrooxidation compared to the hollow counterpart where Cu was selectively etched. Density functional theory (DFT) calculations suggest that the formation of hydroxyl intermediate (OH*) is crucial to detoxify CO poisoning during the electrooxidation processes. The addition of Cu is found to effectively adjust the d band location of the alloy catalyst and thus enhance the formation of *OH intermediate from water splitting, which decreases the coverage of *CO intermediate. Our work demonstrates that the unique compositional anisotropy in alloy catalyst may boost their applications in electrocatalysis and provides a methodology for the design of this type catalyst.

The compatibility between asphalt and nanosilica (nano-SiO2) is critical to determine the performance of nano-SiO2–modified asphalt. However, a comprehensive understanding of the compatibility behavior and mechanism of asphalt components and nano-SiO2 in the modified asphalt is still limited. In this study, the compatibility was revealed through molecular dynamics (MD) simulation. Virgin asphalt, nano-SiO2–modified asphalt, and oxidation aged asphalt models produced with the COMPASS force field; meanwhile, the proposed models were validated by comparisons with reference data. The compatibility of asphalt and nano-SiO2 was analyzed by solubility and the Flory–Huggins parameters and interaction energy. Results show that the solubility parameters decreased with the increase of system temperature while increased with the asphalt’s oxidation level increase. Meanwhile, the compatibility of the asphaltene, resin, and aromatic components in asphalt is better than the compatibility with saturates, which may be due to saturates being volatile; however, the compatibility of the nano-SiO2 and saturates is much better than those with asphaltene, resin, and aromatic components. The incorporation of nano-SiO2 alleviates the volatilization of saturates. The present results provide insights into the understanding of the compatibility behavior and mechanism of nano-SiO2 and asphalt components.

Density functional theory (DFT) calculations have been carried out to investigate the performance of borophosphene in lithium-ion batteries. Our study has revealed the following: (1) the Dirac cone in the electronic structure demonstrates the metallic nature of borophosphene, implying the enhanced electronic conductivity of the anode electrodes; (2) borophosphene shows high adsorption of Li ions with binding energies in the range of -0.6 to -1.1 eV; (3) the theoretical storage capacity is significantly high, up to 1282.7 mA h g-1, and more interestingly, a structural transition is observed in the host borophosphene at a high density of Li ions; (4) at low concentrations, graphene-like borophosphene shows isotropic diffusion of Li atoms with a barrier around 0.5 eV, while at high density, the phosphorene-like borophosphene exhibits a reduced barrier in the range of 0.12-0.14 eV along the zigzag direction, suggesting strong promotion of Li-ion transportation; (5) meanwhile, owing to the structural transition, phosphorene-like borophosphene exhibits highly anisotropic migration of Li ions along the zigzag and armchair directions. These new findings present the great advantages of borophosphene as an anode material in lithium-ion batteries.

The mechanical measurements of nanostructures are crucial to the development and processing of novel nanodevices. Herein, TiO2 nanotubes were synthesized from an electrospun method combined with subsequent heat-treatment. The elastic modulus and fracture strength of a single TiO2 nanotube were measured by atomic force microscopy (AFM). The effect of elastic modulus and dimensional size on the mechanical behaviors of the nanotubes was simulated by the finite element method (FEM).

To realize the effect of Na+ pseudocapacitance on the sodium storage of cathode materials, clewlike carbon-coated sodium vanadium bronze (NaV6O15) nanotubes (Na-VBNT@C) were synthesized via a facile combined sol-gel/hydrothermal method. The resultant Na-VBNT@C delivers high reversible capacities of 209 and 105 mA h g-1 at the rates of 0.1 and 10 C, respectively. Notably, at the higher rate of 5 C (1250 mA g-1), it can retain 94% of the initial capacity after 3000 cycles. It was found that the outstanding rate performance and the long-term cycling life of Na-VBNT@C are primarily due to the Na+ pseudocapacitance. Our study reveals that the design of Na+ pseudocapacitance is beneficial for harvesting the superior performance of NaV6O15 cathode material in sodium-ion batteries.

In a biological microenvironment, free fatty acids (FFA) as ubiquitous biological molecules might interact with nanoparticles (NPs) and consequently change the toxicological responses. However, whether the chemical structures of FFA could influence their interactions with NPs remain unknown. This study investigated the interactions between ZnO NPs and saturated or unsaturated FFA (complexed to BSA), namely stearic acid (SA, C18:0), oleic acid (OA, C18:1), and α-linolenic acid (ALA, C18:3). It was shown that BSA, SA, OA, and ALA increased the atomic force microscope (AFM) heights as well the polydispersity index (PDI) of ZnO NPs. BSA modestly protected THP-1 macrophages from ZnO NP exposure, whereas OA and ALA led to relatively less cyto-protective effects of BSA. Moreover, only co-exposure to ZnO NPs and SA significantly promoted the release of interleukin-8. BSA, SA, OA, and ALA equally changed intracellular ROS and Zn ions associated with ZnO exposure, but co-exposure to ZnO NPs and OA/ALA particularly activated the expression of endoplasmic reticulum stress-apoptosis genes. In combination, these results showed that FFA could influence the colloidal aspects and toxicological signaling pathway of ZnO NPs, which is dependent on the number of unsaturated bonds of FFA.