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The development of high-efficiency, stable and low-cost electrocatalysts is a matter of cardinal significance for large-scale electrolytic hydrogen production from water. In this study, we report a hierarchical electrocatalyst of flower-like FeNiP-LDH (FeNiP on layered double hydroxide) loaded on ultrahigh porosity Co foam. The structure/component superiorities and hydrogen evolution reaction (HER) performance of this electrode were examined in detail. In alkaline solution, the resulting FeNiP-LDH/CF yields a current density of 10 mA/cm2 at an overpotential of -39 mV, which is superior than most documented transition metal phosphides electrocatalysts and even Pt catalyst (~ -53 mV). In particular, this electrode with an undamaged microstructure can maintain its HER activity over 16 h at high current density of 500-600 mA/cm2. Such remarkable HER performance originates from the satisfactory porous nature of Co foam as well as the special surface structure and electronic properties of phosphide/hydroxide. This work not only offers a viable modular approach for the synthesis of high-performance HER electrocatalysts, but also allows an in-depth understanding of structure-activity relationships of multistage 3D materials for energy and catalysis application.

Developing user-friendly electrodes for efficiently producing hydrogen from water to substitute non-renewable fossil fuels is one of the challenges in the hydrogen energy field. For the first time, we have prepared self-supporting ultrahigh porosity cobalt foam loaded with NiCoP/NiOOH nanoflowers (NiCoP/CF) via freeze-drying and phosphorization. The as-prepared hierarchical NiCoP/CF electrodes showed superior catalytic activity for hydrogen evolution reaction (HER) in alkaline media. The one resulted from phosphorization at 350 °C (NiCoP/CF-350) only required overpotential of −47, and −126 mV to deliver geometrical current density of −10 mA cm−2 and −100 mA cm−2, respectively, demonstrating improved catalytic activity than the electrodes prepared using a commercial nickel foam as a support. Moreover, it could retain its superior stability at a current density higher than −500 mA cm−2 for 16 h. Such an outstanding performance can be attributed to the ultrahigh porosity of Co foam support, optimal adsorption energies of HER intermediates (H∗), facile water dissociation on the NiCoP/NiOOH hetero-interfaces, and the assistance of NiOOH facilitating the electrons transfer from the Co foam inside to the NiCoP outside. The work would provide a new strategy for future design of advanced HER electrocatalysts.

Fly ash (FA) is a complex and abundant solid waste created by humans, and has caused environmental issues, for which flotation is an effective technique employed before its comprehensive utilization. However, the complex and hydrophilic characteristics of FA particles cannot naturally fulfill the selective separation by common flotation. Therefore, this study aims to provide an insight into fluid intensification effects on flotation to achieve the enhancement of FA surface property and decarburization. The relevant effects and mechanisms are investigated, based on the measurements of zeta potential, infrared spectroscopy, contact/wrap angle, induction time, size distribution and scanning electron microscopy–energy dispersive spectrometry. Experimental results manifested that the maximum unburned carbon recovery (73.25%) and flotation rate (0.2037 s–1) were achieved with preconditioning energy inputs of 14.23 and 6.57 W·kg–1 respectively. With increasing preconditioning energy inputs, fluid intensification effects could promote the inter-particle collision/attrition, detachment of hydrophilic existence and collector adsorption on particles. Correspondingly, absorbance of some hydrophobic and hydrophilic functional groups was strengthened and weakened respectively, which accounted for the improved interfacial properties, reflected as the increased contact and wrap angles, together with declined induction time. Overall, this article revealed the positive influences of fluid intensification based preconditioning process on rendering particle surface hydrophobic and improving separation performance.

The study in the field of surface nanobubbles has received great progresses since surface nanobubbles were imaged with atomic force microscopy in 2000. Meanwhile, the interest in developing new flotation techniques for separating fine particles keeps increasing. Surface nanobubbles are showing a great potential of application in the field of mineral processing. The formation of agglomerations composed of fine minerals and the easier attachment of a mineral particle to a flotation bubble are the mechanism for the improved flotation performance in the presence of surface nanobubbles. In this work, various aspects regarding surface nanobubbles including the methods for generation, measurement and identification of surface nanobubbles, the responses of surface nanobubbles to external stimuli including pH, salts, surfactants, temperature, pressure, ultrasonication et al., where flotation is usually performed are summarized. At last, we reviewed recent progresses for surface nanobubbles in flotation. This review gives perspectives for further research in the future.

For lithium-sulfur batteries (LSBs), searching for highly efficient host that allows for high sulfur loading and excellent lithium polysulfides (LiPSs) trapping capability is extremely important. Herein, a systematical study with regard to both experimental and theoretical of N/S heteroatoms co-doped polar surface (denoted as NSHC) is conducted to demonstrate the significance of rational structure design as well as rapid sulfur related redox kinetics for high loading cathode. With prominent merits in both heteroatoms doping and hierarchical structure, the as-fabricated NSHC/S cathode guarantees extraordinary sulfur storage, which enables fast sulfur electrochemistry under the conditions of high sulfur loading (6.72 mg cm−2), high sulfur content (80 wt%) and lean electrolyte usage (electrolyte/sulfur ratio: 7.5 μL mg−1). Of particular emphasis is the compact and high utilization of the host structure that ensures the assembled LSB with long and stable durability (606 mAh·g−1 after 100 cycles at 0.1 C and sulfur loading of 6.72 mg cm−2) and superior rate performance (689 mAh·g−1 at 5.0 C and sulfur loading of 2 mg cm−2).

The effects of Co, Fe and Ni catalysts generated from their nitrate precursors on the formation of carbon nanotubes (CNTs) from pyrolysis of phenolic resin were investigated, and the former two performed the best at 873 K, and 1073–1273 K, respectively. Density functional theory calculations indicate that a Co nanocluster requires the lowest energy for forming the five-membered carbon ring (the controlling step in the CNT generation), making Co the best catalyst for the formation of CNTs at relatively low temperatures. On the other hand, molecular dynamics calculations show that an Fe nanocluster has the highest melting point among the three nanoclusters and can retain its integrity at 1280 K, making Fe the best catalyst for the formation of CNTs at relatively high temperatures. Hot modulus of rupture of the CNT (along with additionally formed SiC whisker) reinforced low-carbon MgO–C refractory sample containing 0.25 wt% Fe catalyst was about 20% higher than that of its catalyst-free counterpart.

To meet the high demand for ceramic/superalloy composite structural components in various fields, an advanced high-temperature adhesion technique was firstly developed by preparing a novel inorganic/organic hybrid adhesive suitable for ZrO2 and TC4. Chemical bonding started to work at ∼600°C, and became the crucial bonding mechanism at elevated temperatures. The formation of ZrSiO4 and Ti5Si3 at the interfaces of two substrates not only increased the interfacial connection strength, but also formed two gradient layers with a size of ∼2 μm to effectively alleviate the difference of composition and performance between the adhesive and substrates. In the temperature range of 500–900°C, the matching degree of CTE among ZrO2, adhesive and TC4 is higher, and the maximum difference does not exceed 3×10-6 K-1. Meanwhile, the formation of a composite structure containing various ceramics (ZrO2, SiC and ZrB2) and intermetallics (Ni–Si, Al–Ni), and the improvement of structural compactness of adhesive from 500 to 900°C greatly improved the bonding strength to the maximum value of 31.4 MPa at 900°C. Also, the adhesive pretreated at 900°C showed good thermal cycling resistance, and the strength was still higher than 15 MPa after 50 cycles. For cured adhesive, when used directly in an extreme environment, it can provide bonding strength not less than 5 MPa in the whole temperature range, indicating that the adhesive possessed potential emergency repair convenience. This work significantly broadened the application of high-temperature-resistant adhesion technology in the connection of dissimilar ceramics and alloys.

Development of long-term and sustainable energy economy is one of the most significant technical challenges facing humanity. Photoelectrochemical (PEC) water splitting is regarded as the most attractive approach for conversion of solar energy to chemical energy, with H2 and O2 as the energy carriers. Defect engineering of photocatalytic materials has been proved effective in improving their performances in PEC water splitting process involving three basic steps, i.e., light absorption, charge transfer/separation, and surface catalytic reaction. In this paper, recent developments in using various techniques to introduce, characterize and regulate defects are summarized, based on which the important roles played by defects are highlighted in the development of high-performance defect engineered photoelectrodes for PEC water splitting application. Moreover, current challenges and future perspectives in the field of defect engineering of nanostructures for photoelectrodes are discussed.

High strength SiC reinforced Si3N4 ceramics aerogels (SCSNCAs) were fabricated via foam-gelcasting and subsequent catalytic reaction, utilizing industrial Si and melamine as raw materials, a small amount of incidental Fe impurities in Si powder as the catalyst and cetyltrimethylammonium bromide (CTAB, the amount of 0.075 wt%) as foaming agent. The effects of solid loading level and reaction temperature on phase composition, microstructure and mechanical properties of the as-prepared SCSNCAs were examined. The aerogels prepared at 1423 K using a slurry of solid loading level of 30 wt% (Si:melamine = 3:1, mass ratio) had porosity of 91.9%, having compressive and specific strength of 0.8 MPa and 3.8 MPa·cm3·g−1 exhibited the lowest thermal conductivity of 0.066 W/(m·K) at 473 K. Compared with the control sample (without melamine, i.e., Si3N4 aerogels without the formation of SiC), the specific strength of the SCSNCAs increased by about 10%, which was attributed to the additional reinforcement from SiC whiskers formed in the Si3N4 matrix of the aerogels.

Waste plastics recycling and oil/organics remediation are environmental issues of global concern. In this work, a protectant was introduced, for the first time, to make highly efficient catalysts for pyrolysis of waste plastics into carbon nanotubes (CNTs) with high yield. By using waste polyethylene, Co(NO3)2 and oleylamine respectively as carbon source, catalyst precursor and protectant, a yield as high as 59.0% was achieved. The CNTs exhibited a high adsorption capacity for methylene blue (up to 107.1 mg/g). Furthermore, by combining the CNTs with graphene oxide, a graphene-CNT aerogel with a low density of 8.2 mg/cm3 and high porosity of 96.0% was successfully prepared. It showed excellent hydrophobicity and mechanical stability, as well as high adsorption capacity of 289–410 g/g oil/organic solvent, which was much higher than most of these achieved by carbon-based three-dimensional materials reported previously, making the as-prepared aerogel a very promising adsorbent for oil/water separation.

The morphology and structures of hydroxyapatite (HA) nanomaterials greatly influence their physicochemical properties and bio‐applications. In this study, HA nanostructures with tailored length regulated by different fatty acids were prepared via a solvothermal route. By using ricinoleic acid, linoleic acid and oleic acid as the template, the growth of HA crystals was regulated and the morphology of HA nanomaterials was transformed from long nanowires to short nanowires and then nanorods. The underlying mechanism for the formation of HA nanomaterials synthesized by different kinds of fatty acids under solvothermal condition was proposed. This study provides a simple and environmentally friendly way to obtain HA nanomaterials with tailored length for biomedical applications.

In this paper, SiCp/Al composites were successfully fabricated by selective laser melting (SLM), and the dependence of phase composition, densification behavior, and mechanical properties of the composites on laser power was researched and discussed. The results showed that the density, microhardness and friction resistance of the SLM formed SiCp/Al composites were enhanced with increasing the laser power density, which may be caused by the higher molten pool temperature at higher laser power density. When SiCp/Al composites were prepared at 400 W with a scanning speed of 300 mm/s, the highest relative density of approximately 91.1 % and microhardness of approximately 191 HV0.1 (more than six times higher than that of the selective laser melted pure Al specimens, 191 HV0.1 vs 31 HV0.1) were obtained, and the minimum wear rate and friction coefficient were 1.31 × ×10−5 mm3 N−1 m−1 and 0.38, respectively.

Silicon, which has been widely studied by virtue of its extremely high theoretical capacity and abundance, is recognized as one of the most promising anode materials for the next generation of lithium-ion batteries. However, silicon undergoes tremendous volume change during cycling, which leads to the destruction of the electrode structure and irreversible capacity loss, so the promotion of silicon materials in commercial applications is greatly hampered. In recent years, many strategies have been proposed to address these shortcomings of silicon. This Review focused on different coatings materials (e. g., carbon-based materials, metals, oxides, conducting polymers, etc.) for silicon materials. The role of different types of materials in the modification of silicon-based material encapsulation structure was reviewed to confirm the feasibility of the protective layer strategy. Finally, the future research direction of the silicon-based material coating structure design for the next-generation lithium-ion battery was summarized.

Dynamic evolution of cutting temperature in the ongoing ultra-precision diamond cutting process with ultra-small material removal depth possesses a strong impact on the tool-chip friction states. In the present work, we propose an improved sticking-sliding friction model for diamond cutting of copper with the consideration of coupling thermo-mechanical dynamic evolution of frictional stress at tool-chip interface. Specifically, analytical investigation is performed to derive the correlation of activation conditions of sticking and sliding friction states with not only the evolution of coupled thermal-mechanical friction stress at tool-chip interface, but also the evolution of cutting temperature caused by tool-chip gap-induced heat loss. Subsequently, the effectiveness of improved sticking-sliding friction model is evaluated by finite element simulations and corresponding cutting experiments incorporated with high speed camera monitoring. Furthermore, the effects of depth of cut and rake angle of cutting tool on the tool-chip friction states in diamond cutting of copper are evaluated. Current findings provide insights for understanding and tailoring the tool-chip friction in small-scale metal cutting.

The 3C–SiC whisker was catalytically synthesized with extended graphite and Si powder firing at 1573K using 1 wt% Fe, 3 wt% Co or 3 wt% Ni as catalysts, respectively. First-principles calculation results show the activities of the reactants of the synthesis of SiC could be increased via dwindling the bonding strength of C C, Si–O and C–O bonds. Furthermore, the performance of self-bonded SiC refractories prepared by the present catalytic method was enhanced including the mechanical properties (Fracture toughness of 1.35 MPa﹒m1/2 for the containing Fe catalysts samples, Fracture surface energy of 114 J﹒m−2 and MOR of 32.2 MPa (1473 K) for the sample with Ni catalysts), as well as the TSR (Residual MOR and Residual MOR percentage of 13.17 MPa and 62% at ΔT = 1075 K, respectively). The results indicate that the incorporation of catalysts decreased the reaction temperature by about 100 K as well as facilitated the in-situ formation of 3C–SiC whiskers, which interlinked and connected each other in the matrix of as-prepared self-bonded refractories and improved the high temperature properties. Among them, the Fe NPs presented the best catalytic activity.

The investigation of flow field can provide strong theoretical support for improving the flotation performance of fine particles in a cyclonic flotation column. In this study, particle image velocimetry (PIV) is combined with endoscopic measurement and phase discrimination technique to measure the cross section and axial section of gas–liquid two-phase flow field in a lab-scale cyclonic flotation column. The axial, radial, and tangential velocity of both gas and liquid phases are obtained. Based on the PIV experimental data, computational fluid dynamics (CFD)-based numerical models are validated. The results show the good prediction ability of Eulerian–Eulerian multiphase model, Reynolds stress model (RSM), and Tomiyama drag model. Then the simulated results with validated models are displayed to indicate the flow characteristics of the flotation column. The gas concentration is observed to be higher in the center and low on the sides. The gas phase always moves upward, while the liquid phase moves upward at the axis, downward between the axis and the wall, and upward again near the wall. Overall, this study provides an innovative approach for PIV measurement of complex multiphase flow field, and a useful reference for appropriate numerical models selection.

In this paper, sulfur doped g-C3N4 (S-g-C3N4) was successfully prepared at 500 °C for 3 h via a modified molten salt method using dicyandiamide as the main raw material, trithiocyanuric acid as the sulfur source and LiBr KCl as the reaction medium. The as-prepared S CN5.0% sample (the mass ratio of trithiocyanuric acid to dicyandiamide was 5.0%) composed of irregular flakes showed a band gap of 1.83 eV, which was narrower than that (2.55 eV) of pristine g-C3N4. The S CN5.0% sample also exhibited an outstanding absorption capacity of visible light. Moreover, the photodegradation rate toward methylene blue and tetracycline were respectively 10 and 20 times as high as that of bulk g-C3N4 prepared by conventional heating methods, confirming its superior photocatalytic performance. These results can be attributed to that the replacement of lattice nitrogen with sulfur atom tuned the electronic structure of g-C3N4, improved the absorption of visible light, optimized the separation of photogenerated electron-hole pairs, and consequently enhanced the photocatalytic activity of g-C3N4. Moreover, the trapping experiments implied that hole (h+) and superoxide radical (·O2−) were the main active species in the process of photodegradation.

Nano-whiskers based 3D Si3N4 porous ceramics (3D-NWSNPC) with high-porosity (about 91–93 %), low density (0.17–0.25 g/cm3), low thermal conductivity, and a certain degree of recoverability under cyclic compressive loading and reasonably strengths were prepared at 1423–1523 K via a one-pot foam-gelcasting/nitridation route using inexpensive commercial Si powders as starting materials and hexadecyl trimethyl ammonium bromide as foaming agent. After nitridation at 1523 K, the sample with an original solid loading of 12.5 wt% exhibited the highest compressive strength of 1.9 MPa, even though its density was lowered to 0.25 g/cm3. The sample nitrided at 1473 K had a relative density of 7.3 %. Its compressive and specific strength were respectively 1.1 MPa and 5.5 MPa·cm3 g−1, and its thermal conductivity was as low as 0.074 W/(m K) (measured at 323 K). These outstanding properties would make the as-prepared 3D-NWSNPC a promising candidate for applications in catalysis, filtration, thermal insulation and many other important areas.

ISOBAM-104 stabilized Fe colloidal catalysts were synthesized by in-situ reduction method for hydrogen generation from KBH4 hydrolysis in alkaline solutions. The as-prepared non-noble metal colloidal catalysts contained Fe nanoparticles with an average size of around 1.9 nm as well as uniformly dispersed single Fe atoms, exhibiting a high catalytic activity of 8100 mL-H2 min−1 g-Fe−1, which was higher than that of the Fe catalysts prepared by other protective agents. Such high catalytic activity of the as-synthesized Fe colloidal catalysts could be ascribed to the following two factors: (1) the in-situ formed and well-dispersed Fe atoms that were confirmed by HAADF-STEM, and (2) the superior protective ability of ISOBAM-104 compared with other protective agents, which was validated by a density functional theory (DFT). In addition, the apparent activation energy of Fe colloidal catalysts was 49.85 kJ mol−1, which was in coincidence with DFT calculation results (49.7 kJ mol−1) and lower than most other Fe-based catalysts, implying that the as-prepared Fe colloidal catalyst is a promising candidate for the catalytic hydrolysis of KBH4. This study could provide a promising approach to prepare non-noble metal colloidal catalysts with excellent catalytic activity for hydrogen generation.

With the rapid development of energy sources and aerospace engineering, high-performance thermal insulation materials with multiple functions are attracting more and more attentions. Non-oxide ceramic aerogels have application potential in thermal insulation under harsh conditions owing to their good thermal insulation performance and chemical stability. In this work, TiN aerogels were prepared by a combined freeze-casting and carbothermal reduction-nitridation method utilizing TiO2 and chitosan as raw materials, at 1473 K for 3 h, with a C/TiO2 molar ratio of 3/1. They showed a specific surface area of 167 m2/g and ultralow density of 0.07 g/cm3 (the relative density of 1.3 %). Their thermal conductivity value was only 0.166 ± 0.0054 W/(m K at 673 K (TiO2 solid content of 5 wt%). Moreover, the prepared aerogels possessed reasonably high mechanical strength and good high-temperature service performance, suggesting that they can be used under high-temperature conditions as an insulation material.

Activatable nanoscale drug delivery systems (NDDSs) are promising in maximizing cancer specificity and anticancer efficacy, and a multifunctional metal-organic nanomaterial is one of the new star NDDSs which requires further exploration. Herein, a novel DOX@MnCPs/PEG NDDSs were constructed by first synthesizing Mn3+-sealed coordination particles (MnCPs), modified with a targeted PEGylated polymer, and then loading anticancer drug doxorubicin (DOX). MnCPs were prepared from the assembly of Mn3+ ions and hematoporphyrin monomethyl ether (HMME) molecules. Furthermore, MnCPs had an average size of ∼100 nm and a large surface area (∼52.6 m2 g-1) and porosity (∼3.6 nm). After the loading of DOX, DOX@MnCPs/PEG exhibited a high DOX-loading efficacy of 27.2%, and they reacted with glutathione (GSH) to confer structural collapse, leading to the production of Mn2+ ions for enhanced magnetic resonance imaging (MRI), free HMME for augmented photodynamic effect, and free DOX for chemotherapy. As a consequence, these DOX@MnCPs/PEG NDDSs after intravenous injection showed efficient tumor homing and then exerted an obvious suppression for tumor growth rate by synergistic photodynamic-chemo therapy in vivo. Importantly, most of the DOX@MnCPs/PEG NDDSs could be gradually cleared through the renal pathway, and the remaining part could slowly be metabolized via the feces, enabling high biosafety. Therefore, this work provides a type of GSH-sensitive NDDS with biosafety, caner specificity, and multifunctionality for high synergistic treatment efficacy.

CuS materials exhibit excellent near infrared (NIR) photoabsorption and photothermal effect, but they are lack of magnetic resonance imaging (MRI) ability. Fe-based nanomaterials possess MRI capacity, but they usually exhibit poor NIR photoabsorption. In order to solve the above problems, we synthesize three kinds of CuxFeySz samples, including FeS2, CuFeS2 and Cu5FeS4 nanomaterials. With the Cu/Fe ratios increase from 0/1.0 to 1.0/1.0 and 5.0/1.0, the localized surface plasmon resonances (LSPRs) characteristic peaks shift to longer wavelength, and the photothermal transduction efficiencies go up from 24.4% to 36.6% and 45.9%. Thus, Cu5FeS4 is found to be the most excellent sample. Especially, Cu5FeS4 exhibits photothermal-enhanced Fenton effect, which can produce hydroxyl radical (·OH) under a wide pH range (e.g., pH = 5.4–7.4) to realize the chemodynamic effect. In addition, Cu5FeS4 can be employed as an efficient MRI contrast agent. When Cu5FeS4 dispersion is intravenously injected into the mouse, the tumor can be detected by MRI as well as thermal imaging, and eliminated through photothermal-enhanced chemodynamic effect. Therefore, Cu5FeS4 can be used as an efficient “one-for-all” type agent for MRI-guided photothermal-enhanced chemodynamic therapy of tumor.

The rational design and preparation of hierarchical hollow structures have promising potential in electrochemical energy storage systems. In this paper, double-shell hollow carbon fibers (DSHCFs) with tunable thickness and shell spacing are prepared using hollow electrospun polystyrene fibers as the hard template and in situ coated polypyrrole as the carbon source. The as-prepared DSHCFs with an optimized structure exhibit a submicrometer shell spacing and a nanoscaled shell thickness, which guarantees sufficient contact area with the electrolyte and provides abundant electrochemical active sites for Li+ storage. Owing to the unique structural advantages, a DSHCF-based anode shows favorable transport kinetics for both Li+ ions and electrons during the lithiation/delithiation process, and a high reversible capacity of 348 mAh g-1 at 5.0 A g-1 is well maintained even after 500 cycles with no obvious capacity attenuation. Particular emphasis is given to kinetic Li+ storage mechanisms in DSHCFs that are discussed in detail, providing a new avenue for developing high-performance carbon materials for the practical application of energy storage devices.

Appropriately adapted comprehensive mechanical properties, degradation behavior and biocompatibility are prerequisites for the application of Zn-based biodegradable implants. In this study, hot-extruded Zn–0.5Cu–xFe (x = 0.1, 0.2 and 0.4 wt%) alloys were fabricated as candidates for biodegradable materials for guided bone regeneration (GBR) membranes. The hot-extrusion process and Cu alloying were expected mostly to enhance the mechanical properties, and the Fe alloying was added mainly for regulating the degradation. The microstructure, mechanical properties and in vitro degradation behavior were systematically investigated. The ZnCuFe alloys were composed of a Zn matrix and FeZn13 phase. With increasing Fe content, a higher FeZn13 phase precipitation with larger particles was observed. Since elongation declined significantly until fracture with increasing Fe content up to 0.4 wt%, the ZnCuFe (0.2 wt%) alloy achieved a good balance between mechanical strength and ductility, with an ultimate tensile strength of 202.3 MPa and elongation at fracture of 41.2%. Moreover, the addition of Fe successfully accelerated the degradation of ZnCuFe alloys. The ZnCuFe (0.2 wt%) alloy showed relatively uniform corrosion in the long-term degradation test. Furthermore, extracts of the ZnCuFe (0.2 wt%) alloy showed no apparent cytotoxic effects against L929 fibroblasts, Saos-2 osteoblasts or TAg periosteal cells. The ZnCuFe (0.2 wt%) alloy exhibited the potential to inhibit bacterial adhesion of Streptococcus gordonii and mixed oral bacteria. Our study provides evidence that the ZnCuFe (0.2 wt%) alloy can represent a promising material for the application as a suitable GBR membrane., Graphical abstract Image 1, Highlights • Hot-extruded Zn-0.5Cu-xFe alloys designed for biodegradable GBR membrane application. • The Zn–0.5Cu–0.2Fe alloy showed a good balance between tensile strength and ductility. • The degradation behavior was improved when the Fe content is less than 0.4 wt%. • The Zn–0.5Cu–0.2Fe alloy exhibited good cytocompatibility and antibacterial ability. • This Zn-based alloy provide appropriately adapted properties for degradable GBR membrane.

Spearhead columnar mullite was synthesized by in-situ reaction with V2O5 as additive. When the content of V2O5 was 7 wt%, the length of the spearhead columnar mullite was the longest with an aspect ratio of about 3.5. Furthermore, columnar self-reinforced mullite porous ceramics were prepared by a foam-gelcasting method, and the effects of V2O5 content on the rheological and gelling properties of mullite slurries as well as the microstructure, physical property and thermal insulation property of the prepared mullite porous ceramics were studied. The results showed that the flexural strength and compressive strength of the porous ceramics with 63% porosity prepared by using 2 wt% V2O5 additive were respectively as high as 13.9 and 41.3 MPa, and the thermal conductivity was about 1.04 W m−1 K−1.

Lithium–sulfur batteries (LSBs) have become promising next-generation energy storage technologies for electric vehicles and portable electronics, due to its excellent theoretical specific energy. However, the low conductivity of sulfur species, notorious lithium dendrites, the severe “shuttle effect” of polysulfides (LiPSs) and the inferior kinetic reaction for LiPSs/Li2S conversion during discharge–charge have seriously hindered their practical application, and also pose potential safety hazards. Owing to their superior porous architectures, high specific surface areas, excellent structural designability, functional modifiability, abundant active sites and flexibility of carbon-containing electrospun nanofibers (CENFs), they exhibited the superior characteristics that can simultaneously solve the above issues. In this review, we summarize the recent progress and application of CENFs in LSBs. First, we provide a brief introduction to the structure and composition controlled of carbon nanofibers by electrospinning. We then review progress in recent developments of CENFs for LSBs including cathodes, anodes, separators, and interlayers. We focus on how to solve practical issues that arise when the CENFs are applied to various parts of LSBs, and the relevant working mechanisms are described, from high sulfur loading and Li dendrites suppression to LiPSs’ confinement and conversion. Finally, we summarize and propose the existing challenges and future prospects of CENFs, for the design and architecture of electrochemical components in Li–S energy storage systems.

Semiconductor combination is one of the most common strategies to obtain high-efficiency photocatalysts; however, the effect mechanism of composition ratio on micro-structure and photocatalytic activity is remaining unclear. In this study, a case of g-C3N4 quantum dots@SnS2 (CNQDn@SnS2) heterojunction with different ratio of CNQD is used to uncover the origin of optimum and excess composition for photocatalysts. Research on the functional mechanism of the optimum composition shows that 0.8 wt.% CNQD are completely attached to the non-(001) facets of SnS2, which benefits the formation of type-II heterojunction, resulting in an optimal pollutant degradation and mineralization efficiency. For the excess composition, both experiments and theoretical calculations confirm that excess CNQD (the part exceeding of 0.8 wt.%) located on the (001) facet of SnS2, leading to the type-I band alignment of this heterojunction, which severely restricts the separation of photo-induced charge carriers, and thus reduces their lifetime. This work makes the functional mechanism of composition ratio on micro-structure and photocatalytic activity clearer. Related research results provide a new insight into semiconductor combination study and take an important step toward the rational design of highly active photocatalysts.

Owing to their excellent thermostability, superior electrical conductivity, and tunable surface chemistry, two-dimensional transition-metal carbides, nitrides, and carbonitrides (MXenes) are highly...

Background/Objective: As the most aggressive subtype of breast cancer, triple-negative breast cancer (TNBC) with high mortality lacks effective treatment options and results in poor prognosis. Photothermal therapy (PTT) has emerged as a potential anticancer strategy. Until now, the construction of multifunctional photothermal agents is vital importance for effective PTT generally. In this work, the novel core-shell gold nanorods (GNs)@iron-based metal-organic framework (Fe-MOF) was firstly successfully fabricated for magnetic resonance imaging (MRI) guided PTT in TNBC. The inner GNs have excellent photothermal properties and the outer Fe-MOF shell endow the nanocomposite with superior T2 MRI property.Methods: The GNs @ Fe-MOF was firstly prepared by a layer-by-layer technique. Prepared nanocomposite was characterized by measuring measuring measuring transmission electron microscope (TEM), UV-Vis-NIR absorption spectra, powder X-radiffraction (XRD) patterns. MR imaging of nanocomposite was assessed in vitro and in vivo. The biocompatibility and photothermal cytotoxicity of the nanocomposite was assessed by a CCK-8 assay. The photothermal effect of nanocomposite in vivo was evaluated by monitoring tumor growth. The tumor tissues were analyzed by Hema-toxylin and eosin (H&E) to further analyze photothermal effect. The toxicity of the materials in major organs was also investigated by H&E.Result: The core-shell GNs @ Fe-MOF was successfully prepared and displayed excellent dispersion. The nanocomposite possessed good biocompatibility and effectively killed tumor cells under laser irradiation. Meanwhile, the nanocomposite showed clear signal contrast in T2-weighted images in vitro and in vivo. Moreover, the nanocomposite significantly inhibited tumor growth under laser irradiation in vivo. H&E showed that the nanocomposite caused serious damage to tumor tissue under laser irradiation.Conclusion: The current work developed a novel multifunctional core-shell GNs @ Fe-MOF with good biocompatibility for MRI guided PTT in TNBC.Keywords : Magnetic resonance imaging, Photothermal therapy,gold nanorods@iron-based metal-organic Framework Citation Format: Jingchao He, Haijun Zhang. Core−shell structured gold nanorods@iron-based metal-organic framework for magnetic resonance imaging guided photothermal therapy in triple-negative breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS14-28.

Graphitic carbon nitrides have CO2 photoreduction ability, but their activities are limited by the low potential and mobility of photogenerated carriers. Herein, ultrathin mesoporous graphitic carbon nitride nanosheets (CNNS) synchronously decorated with functional cyano groups and nitrogen vacancies were prepared by a facile molten salt route. The CNNS presented unprecedentedly excellent gas-phase CO2 photoreduction performance under visible light irradiation without any co-catalyst or a sacrificial agent, and have a CH4-yielding rate of 23.0 μmol g−1 h−1 and a selectivity of 97.9%. This boosted performance can be attributed to the synergistic effect of cyano group decoration, abundant nitrogen vacancies and extremely high surface area, which improve electron storage, charge carrier mobility, CO2 affinity, and optimize the energy band structure. This work demonstrates that a structural optimization combined with defect design of carbon nitride framework is a powerful approach to improve the photocatalytic activity, providing an accessible way to design highly efficient carbon-based photocatalysts.

Mg–Zn alloys have attracted much attention as biodegradable alloys owing to their superior mechanical properties and excellent biocompatibility. However, their corrosion/degradation behaviour has become a major issue for various biomedical applications. To understand their corrosion behaviours in aqueous environments, the first-principles informed Pourbaix diagrams, that is, electrochemical phase diagrams with respect to electrode potential and solution pH, were constructed for Mg–Zn alloys and compared with experimental observations. It was found that for Mg-rich alloys, the MgZn phase has a higher potential than the Mg matrix and may act as a cathode, resulting in galvanic corrosion, while for Zn-rich alloys, the phase Mg2Zn11 corrodes first. In Zn-rich alloys, Mg(OH)2 preferably precipitates under alkaline conditions, thus hindering the increase in pH and preventing the release of dissolved ZnO22− ions. In a Cl-containing solution, the soluble ZnCl2 eases the corrosion of the Zn matrix by decreasing the corrosion potential. These results are supported by various experimental observations; thus, they provide an in-depth understanding of the degradation behaviour of various Mg–Zn alloys as well as a feasible pathway in the design of biocompatible Mg–Zn alloys with first-principles informed Pourbaix diagrams.

The quest for high-energy-density materials is an active research field in materials science and industrial applications. Using the swarm-intelligence structure search method and first-principles calculations, we identify several hitherto unknown gadolinium polynitrides (e.g., GdN2, GdN3, GdN4, and GdN6) under high pressures. Interestingly, P GdN6 with armchair- and antiarmchair-like polynitrogen chains can be obtained via the mixtures of GdN or GdN3 and pure nitrogen above a moderate pressure of 27 GPa. Further investigations reveal that P GdN6 is dynamically stable at ambient pressure and has high thermal stability up to 1000 K, suggesting that GdN6 can be recovered to ambient conditions upon synthesis under compression. Its good stability is mainly due to the covalent N–N and ionic Gd–N bonds. Remarkably, P GdN6 has excellent explosive performance comparable to that of TNT from the standpoint of detonation velocity (11.79 km s−1) and detonation pressure (901 kbar). More importantly, GdN6 is found to have a high energy density (1.62 kJ g−1) and volumetric energy density (8.28 kJ cm−3), which make it become the first high-energy-density material amongst lanthanide nitrides. This work provides in-depth insights into the structures and properties of gadolinium nitrides and opens up opportunities to explore high-energy-density materials in lanthanide nitrides.

Nanocrystalline diamonds (NCDs) are promising structural materials due to their extraordinary mechanical properties such as ultrahigh hardness and excellent toughness, however, a rational design rule in plasticity and fracture through controlling nanostructures at different length scales is far from being explored. By means of atomic simulations and plasticity theory in the present paper, we comprehensively explored the plastic deformation behaviors of a series of well-defined NCDs by varying amorphous interfacial layers (AILs) and internal defects, e.g., twin boundary, stacking fault, π-bonded interface, and fivefold twin. It was observed that the effect of internal defects on the mechanical response of NCD can be attributed to the competition between dislocation blocking process and interface sliding process. The introduction of AIL at grain boundary (GB) is found to provide an effective solution to decrease both dislocation nucleation and penetration at GBs. These findings provide not only a mechanistic insight into the unique strengthening and toughening in various NCDs, but a rational guidance in designing novel superhard carbon materials with superior performance by engineering internal defects and GB structures at different length scales.

Magnetic-fluorescent nanocomposites have a tremendous potential in biomedicine realms as a revolutionary dual-modality probe tool for more accurate medical detection. However, complicated and inefficient postprocesses pose obstacles to obtaining high-quality magnetic-fluorescent nanocomposites. Thus, the fabrication of magnetic-fluorescent functional nanocomposites via a simple, effective, and ideal method remains a challenge and is still waiting to be tapped. The new synthesis approaches are becoming impending demands and probably enable us to address these above-mentioned problems. In this contribution, we present a novel self-assembly synthesis route for the construction of magnetic-fluorescent bimodal imaging nanocomposites rather than adopting sophisticated postpreparative processes. The Fe3O4 and quatum dots (QDs) nanocomposites were cross-linked fleetly by cerium(III) ion driven coordination bonds in which the cerium(III) ions served as the cross-connecting node and the carboxylate groups acted as bridging ligands. The potential application for dual-modality imaging capability was validated on tumor-bearing mice. This ingenious strategy was extremely efficient and handy for the magnetic-fluorescent Fe3O4-QDs nanocomposite construction. Significantly, our cerium(III) ion driven self-assembly method probably has a wide applicability for nanoparticles and organic molecules containing carboxyl groups but extensive explorations are still necessary.

Thermal-sprayed aluminum (Al) coatings are widely used for corrosion protection in marine environments. The corrosive nature of seawater and the synergy with marine microbes make for aggressive service environments for Al coatings. In this study, Al coatings were deposited on 316L stainless steel (316L SS) substrates by using wire arc spraying. Chlorella vulgaris, a typical marine fouling algae, was used to investigate the effects of biofilm adhesion on the electrochemical behavior of wire arc-sprayed Al coatings in artificial seawater environment. Electrochemical measurements via dynamic potential polarization curves and electrochemical impedance spectroscopy were used to monitor the corrosion behavior after attachment of microbes on Al coatings and bare, uncoated 316L SS. Analysis of the corrosion products was conducted using scanning electron microscope and energy-dispersive spectrum. The results showed that the Chlorella vulgaris biofilm slowed the corrosion of the Al coatings. This suggested that Chlorella vulgaris biofilm was a critical contributing factor to the corrosion behavior of the Al coatings. Moreover, a mechanism was suggested to illustrate the corrosion behavior of Al coatings in the presence of Chlorella vulgaris.

Numerous oxygen elements are present on the oxidized coal surfaces, resulting in the difficulties for flotation. In this study, the enhancement of oxidized coal flotation using the impact flow cond...

MgAl2O4 ceramics with high porosity and performance were fabricated via foam gel casting at 1673–1823 K using MgAl2O4 as the raw material and a small amount of V2O5 (0.25 wt%) as a sintering additive. The variations in the physical properties of the final porous MgAl2O4 samples at ambient temperature demonstrated that their flexural, compressive, and specific strength increased with the addition of a small amount of V2O5 as a sintering aid. However, the thermal insulation properties of the as-fabricated MgAl2O4 ceramics exhibited an inverse tendency. A porous MgAl2O4 ceramic containing 0.25 wt% of V2O5 and fired at 1823 K had flexural and specific strength values of 4.2 MPa and 14.0 (MPa cm3)/g, respectively, representing improvements over those reported in the literature at a similar porosity (72.0%). Moreover, a low thermal conductivity of approximately 0.24 W/(m·K) was measured at 473 K, which may be attributed to the relatively high porosity and high proportion of small pores with diameters less than 50 μm.

Interlayer coupling in two-dimensional (2D) layered materials plays an important role in controlling their properties. 2H- and 3R-MoS2 with different stacking orders and the resulting interlayer coupling have been recently discovered to have different band structures and a contrast behavior in valley physics. However, the role of carrier doping in interlayer coupling in 2D materials remains elusive. Here, based on the electric double layer interface, we demonstrated the experimental observation of carrier doping-enhanced interlayer coupling in 3R-MoS2. A remarkable tuning of interlayer Raman modes can be observed by changing the stacking sequence and carrier doping near their monolayer limit. The modulated interlayer vibration modes originated from the interlayer coupling show a doping-induced blue shift and are supposed to be associated with the interlayer coupling enhancement, which is further verified using our first-principles calculations. Such an electrical control of interlayer coupling of layered materials in an electrical gating geometry provides a new degree of freedom to modify the physical properties in 2D materials.

Nepheline porous ceramics with improved strength and well thermal insulation performance were synthesised at 850–1000°C by a foam-gelcasting technology, using waste zeolite powders, triethanolamine...

Recently, two-dimensional transition metal dichalcogenides, particularly WS2, raised extensive interest due to its extraordinary physicochemical properties. With the merits of low costs and prominent properties such as high anisotropy and distinct crystal structure, WS2 is regarded as a competent substitute in the construction of next-generation environmentally benign energy storage and conversion devices. In this review, we begin with the fundamental studies of the structure, properties and preparation of WS2, followed by detailed discussions on the development of various WS2 and WS2-based composites for electrochemical energy storage and conversion applications. In the end, some prospective prospects and promising developments of WS2 in these fields are proposed.

Although nickel-based catalysts display good catalytic capability and excellent corrosion resistance under alkaline electrolytes for water splitting, it is still imperative to enhance their activity for real device applications. Herein, we decorated Ni0.85Se hollow nanospheres onto reduced graphene oxide (RGO) through a hydrothermal route, then annealed this composite at different temperatures (400 °C, NiSe2-400 and 450 °C, NiSe2-450) under argon atmosphere, yielding a kind of NiSe2/RGO composite catalysts. Positron annihilation spectra revealed two types of vacancies formed in this composite catalyst. We found that the NiSe2-400 catalyst with dual Ni-Se vacancies is able to catalyze the oxygen evolution reaction (OER) efficiently, needing a mere 241 mV overpotential at 10 mA·cm−2. In addition, this catalyst exhibits outstanding stability. Computational studies show favorable energy barrier on NiSe2-400, enabling moderate OH− adsorption and O2 desorption, which leads to the enhanced energetics for OER.

LiCoO2 (LCO) possess a high theoretical specific capacity of 274 mAh g−1, and currently LCO charged to 4.48 ​V with a capacity of ~190–195 mAh g−1 is penetrating the commercial markets. Scalable strategies to further enhance the performance of LCO are highly attractive. Here, we develop a scalable ball-milling and sintering method to tackle this long-standing challenge by modifying LCO surface with only 1.5–3.5% ceramic solid electrolyte nanoparticles, specifically Li1.5Al0.5Ge1.5(PO4)3 (LAGP) as an example. Consequently, the atomic-to-meso multiscale structural stabilities have been significantly improved, even with a high cut-off voltage of 4.5 ​V vs. Li/Li+, leading to excellent electrochemical stabilities. The nano-LAGP modified Li|LCO cell exhibits high discharge capacity of 196 mAh g−1 at 0.1 ​C, capacity retention of 88% over 400 cycles, and remarkably enhanced rate capability (163 mAh g−1 at 6 ​C). These results show significant improvement compared to the Li|LCO cells. The as-prepared graphite|LAGP-LCO full cells also show steady cycling with 80.4% capacity retention after 200 cycles with a voltage cut-off of 4.45 ​V. This work provides a simple and scalable approach to achieve stable cycling of LCO at high voltage with high energy density.

Photoluminescence materials with reversible luminescence regulation properties have great potential for applications in photoswitches, optical sensing, and high-density optical data storage devices. In this work, a series of Pr3+-doped Bi4Ti3O12 (BiT) ceramics were synthesized by a high-temperature solid-phase reaction method. It is well known that BiT is the most famous one within the Aurivillius ferroelectric (FE) system. Previous works routinely focused on the FE-related properties of BiT-based compounds, but little attention has been devoted to the luminescence, especially the luminescence modulation performance. Here, a large and reversible photoluminescence modulation by alternating visible light irradiation and thermal stimulus based on photochromic (PC) process was achieved. Meanwhile, the influence of sintering temperature on the luminescence modulation behavior was also illustrated. The luminescence regulation properties of the Pr3+-doped BiT ceramics prepared at optimized sintering temperature were investigated in detail. The mechanisms connected to the luminescence, luminescence manipulation, and PC effect were discussed. It is believed that Pr3+-doped BiT materials can be utilized as a kind of ideal optical medium for future information storage device.

In this work, a series of intensive laboratory tests are conducted to measure the material constituents, mechanical properties, and to examine macro-micro-failure modes of various types of rocks from tight gas reservoirs in the Da Qing oilfield in China. A set of key parameters are experimentally determined, including porosity, mineralogical compositions, microstructure, Young’s modulus, Poisson’s ratio, triaxial compressive strength, as well as macro- and micro-morphology failure modes. The relationships of these parameters are systematically analyzed, and the effects of the material constituents and microstructure characteristics such as cementation type, porosity, and mineral composition on rock mechanical properties are revealed as well as the patterns of micro- and macro-failures in types of rocks are investigated. The result shows that the micro-failure mainly exhibits features of transgranular and intergranular porous polymer fracture, and the macro-failure modes are mainly three types: shear-dominated, mixed shear–tensile and mixed tensile–shear. The mixed tensile–shear failure has mainly tensile fractures with branch fractures crossing each other, which forms a complex system fracture network. These findings are of importance for “sweet pot” evaluations, wellbore stability analysis, and hydraulic fracturing design for oil and gas production in tight gas reservoirs.