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Ionic liquids (ILs) have attracted increasing attention since last few decades due to their high molecular design abilities and wide applications in different fields. In this study, four novel fluorescent isoquinolino [2,1-a]quinoxalin-5-ium ILs were designed and synthesized via a two-step process including a simple dual Schiff's base formation and a subsequent [RhCp∗Cl2]2-catalyzed oxidative C–H activation/annulation reaction. The as-synthesized ILs were extensively characterized using FT-IR, 1H-NMR, 13C-NMR, 19F-NMR, HSQC-NMR, HMBC-NMR and HR-MS. Their photophysical properties were determined by steady-state fluorescence spectroscopy. The results demonstrate that all these ILs showed dual or triple emissions, large stokes shift (90 nm) and mechanochromic behaviors. Basing on solvatochromism and titration experiments, it is thought that the emission bands of the ILs are raised from their local excited states, charge transfer states or excited state proton transfer of cations, while the substitute effect of these quinoxaline derived ILs on their stokes shifts is negligible.

It is extremely challenging to construct three-dimensional (3D) crystalline covalent organic frameworks (COFs) with flexible building blocks and to further explore their tunable or adaptive charact...

Ni-based metallic foams possessing large specific surfaces and open cell structures are of specific interest as catalysts or catalyst carriers for electrolysis of water. Traditional fabrication of Nickel foam limits the element modification choices to several inert transition metals only on polymer foam precursor and subsequent preparation of foam-based catalysts in aqueous solution or organic electrolyte. To expand the modification horizon, molten salt with wide electrochemical window and fast ion diffusion can achieve the reduction of highly active elements. Herein, we reported is a general and facile method to deposit directly of highly reactive element La and prepare hierarchical honeycomb LaNi5 alloy on Ni foam (ho-LaNi5/NF). This self-supporting electrode presents excellent electrical coupling and conductivity between the Ni foam and LaNi5, which provides a 3D self-supported heterostructure with outstanding electrocatalytic activity and excellent durability for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). It exhibits excellent overpotential (1.86 V) comparable to commercial coupled IrO2//Pt/C (1.85 V) at a high current density of 100 mA cm−2. This work may pave the way for fabricating novel 3D self-supported honeycomb alloy that can be applied as electrode for usage of clean energy.

A series of vibratile π-extended dihydrophenazines (BPs) and a tetrahydrodiphenazine (TP) were synthesized via direct C–N coupling reactions. Structural alterations of the fused acene wings lead to...

To understand the relationships between channel size and ion selectivity, we have developed a new type of artificial ion channel based on pore-forming helical polymers consisting of phenanthroline-...

Dual-phase rare-earth-zirconate high-entropy ceramics have gained significant research interest recently. However, the large composition complexity and serious lattice distortion from multi-components doping increase the uncertainty of their crystal structures. In this work, a series of dual-phase rare-earth-zirconate medium- and high-entropy ceramics are successfully fabricated. Results of this study indicate that these dual-phase ceramics are composed of pyrochlore and fluorite structures. Simultaneously, a principal element design criterion of the pyrochlore-fluorite dual-phase medium- and high-entropy ceramics is proposed. The phase structures of pyrochlore-fluorite dual-phase samples are co-determined by the average ionic radius ratio and the size disorder parameter. When the average ionic radius ratio is in the range of 1.4 to 1.5 and the size disorder parameter is larger than 5%, it is more inclined to form pyrochlore-fluorite dual-phase structure. This work has an important guiding significance to the composition design of pyrochlore-fluorite dual-phase medium- and high-entropy ceramics.

Designing a core–shell nanointerface is beneficial for enhancing the photocatalytic performance of hydrogen peroxide (H2O2) production. Hence, a direct Z-scheme one-dimensional (1 D) CuBiOS@CuBi2O4 nanorods with a core (oxide)-shell (sulfide) nanostructure and O S interpenetrated nanointerface was controllably synthesized through in-situ anion exchange. The formation of O S interpenetration at the heterogeneous interface with surface oxygen vacancies could effectively boost light absorption, reduce the interface contact resistance, facilitate band bending, and thus enhance charge separation and transfer as a “bridge”. The as-prepared catalyst with tunable O S nanointerface greatly improved the photocatalytic performances in the H2O2 production with a yield of 201.9 μmol·L-1 and the in-situ generated H2O2 effectively accelerated the reduction of chromium(VI) (Cr(VI), 95.4% within 15 min). The excellent performances were due to the O S interpenetration with rich oxygen vacancies and unique shell-core structure with intimate contact inter-doping nanointerface. Moreover, the photocatalytic mechanism was discussed in detail. This work might provide a guideline in the design and construction of high-performance catalysts with well-defined nanointerface for various applications.

Direct Ink Writing (DIW) has demonstrated great potential as a versatile method to 3D print multifunctional structures. In this work, we report the implementation of hydrogel meta-structures using DIW at room temperature, which seamlessly integrate large specific surface areas, interconnected porous characteristics, mechanical toughness, biocompatibility, and water absorption and retention capabilities. Robust but hydrophobic polymers and weakly crosslinked nature-origin hydrogels form a balance in the self-supporting ink, allowing us to directly print complex meta-structures without sacrificial materials and heating extrusion. Mechanically, the mixed bending or stretching of symmetrical re-entrant cellular lattices and the unique curvature patterns are combined to provide little lateral expansion and large compressive energy absorbance when external forces are applied on the printed meta-structures. In addition, we have successfully demonstrated ear, aortic valve conduits and hierarchical architectures. We anticipate that the reported 3D meta-structured hydrogel would offer a new strategy to develop functional biomaterials for tissue engineering applications in the future., Graphical abstract In this work, we demonstrate the implementation of hydrogel meta-structures using direct ink writing at room temperature, which seamlessly integrate large specific surface area, interconnected porous characteristics, mechanical toughness, biocompatibility, water sorption and diffusion capability. Robust but hydrophobic polymers and weakly crosslinked nature-origin hydrogels form a balance in the self-supporting ink, allowing us to directly print complex meta-structures without sacrificial materials and heating extrusion. Mechanically, the mixed bending or stretching of symmetrical re-entrant cellular lattices and the unique curvature patterns are combined to provide little lateral expansion and large compressive energy absorbance when external forces are applied on the printed meta-structures. In addition, we have successfully demonstrated ear, aortic valve conduits and hierarchical architectures. We anticipate that the reported 3D meta-structured hydrogel would offer a new strategy to develop functional biomaterials for tissue engineering and bone repair.Image 1, Highlights ⁃ We develop a self-supporting hydrogel ink to seamlessly integrate the mechanical toughness and 3D printability of direct ink writing scaffolds at room temperature, without extra sacrificial materials or UV irradiation curing ⁃ The ink based on nano-composites imparts water sorption and diffusion capability, biocompatibility and mechanical toughness, as well as superior 3D printability ⁃ We successfully print human ear, human aortic valve conduits and hierarchical Gyroid meta-structures with tunable density and infill pattern. ⁃ The printed structures show substantial compressive energy absorbance, excellent water sorption and diffusion capability, and bioactivity ⁃ Our method could be generalized to produce a wide combination of weakly crosslinked nature-origin hydrogel and biomedical thermoplastic polymers

Magnetically anisotropic nanoparticle monolayer films are of great interest for the development of applications such as high-density data storage, sensors. However, the formation of large-scale magnetically anisotropic monolayer film is a challenging task. Here, we provide a new way to fabricate large-scale area of Fe3O4 nanoparticle monolayer films by vacuum deposition technique (matrix-assisted pulsed laser evaporation, MAPLE). During the deposition process, only interactions between nanoparticles influence nanoparticle self-assembly behaviors. A strong magnetic anisotropy, characterized by in-plane and out-of-plane coercivity and saturation field obtained by DCM (dynamic cantilever magnetometry), was obtained both in cubic and spherical Fe3O4 nanoparticle monolayer films. The inter-particle dipolar interaction but not crystal anisotropy is responsible for this effective magnetic anisotropy, which has been proved by Monte-Carlo simulations.

One type of new light-responsive hierarchical metal organic framework (MOF) has been successfully prepared using Co(NO3)3·6H2O as the metal salt and 4,4′-azobenzenedicarboxylic acid as the ligand by microwave method for the first time. It is found that MOF [Co(AzDC)] exhibits a light-responsive characteristic to SO2 adsorption due to the presence of azo group from the ligand. The light-responsive hierarchical MOFs are incorporated into Matrimid® 5218 (PI) matrix to prepare mixed matrix membranes (MMMs) for gas separation application. The morphology, crystallinity, chain mobility and thermal stability of MMMs are explored. Results show that Co(AzDC) may elevate both the CO2(SO2) permeability and CO2(SO2)/N2 selectivity of the MMMs. In particular, the Co(AzDC) doped MMMs exhibit the significantly improved CO2(SO2)/N2 selectivity from 33 (123) for PI control membrane to 78 (420) for MMMs, overcoming the 2008 Robeson upper bound for CO2/N2 system. Size-sieving effect of Co(AzDC) with pore size 0.35 ​nm enhances the selectivity, while the –N N- group from Co(AzDC) shows affinity to CO2 molecular rather than N2, also elevating selectivity of MMMs. In brief, enhanced selectivity of high-performance membrane is attributed to incorporation of Co(AzDC) particles, which displays synergistic effects both in size-sieving and CO2-philic interaction for CO2/N2 separation. Smart highly selective interface is constructed in MMMs by switching the configuration of MOFs from cis to trans. The SO2 permeability and SO2/N2 selectivity of MMMs are investigated under both visible light and ultraviolet light states, and the SO2/N2 separation performance under visible light is notably improved in comparison with that under ultraviolet light state.

The hydrophobic ionic liquids/water two-phase system was developed to prepare CuO nano particles. The catalytic activity of the synthesized CuO was investigated by photodegradation of 4-nitrophenol (4-NP) in the presence of H2O2 under visible light irradiation. The optical properties of the synthesized CuO were characterized by ultraviolet–visible (UV–Vis) diffuse reflectance spectroscopy (DRS). Experimental results indicated that the band gap energy (Eg), conduction band edge potential (ECB) and valence band edge potential (EVB) of the synthesized CuO were 1.37 eV, 0.625 eV and 1.995 eV, respectively. A degradation efficiency of 4-NP (4.8 mmol L−1) as high as 95.3% could be achieved under the conditions of pH 6.0, 0.48 g L−1 of CuO dosage, 1.4% of H2O2 dosage and 90 min of degradation time. The synthesized CuO exhibited poor catalytic activity under alkaline conditions due to the disassociation of 4-NP, which elevated the repulsion between CuO and the 4-NP anions. The synthesized CuO nano particles exhibited higher catalytic activity compared with the catalysts reported in literature. Furthermore, the synthesized CuO nano particles could be reused at least six times without decreasing their catalytic activity. Compared with the traditional hydrothermal method, mild operating conditions and time saving are the advantages of the developed method for the preparation of CuO.

In granular superconductors, the grain boundaries are closely related to the vortex dynamics and the macroscopic superconducting properties. In our research, Pb films with different grain sizes were prepared by tuning the substrate temperature. With the grain size decreasing, Pb films are prone to feature the anomalous magnetization jumps in the M − T curves, while in the M − H curves flux avalanche happens. Both phenomena appear in the same region of the H − T phase diagram and thus are considered to have the same origin. The further theoretical analysis shows that with grain size decreasing the pinning mechanism evolves from a mixed δTc and δl pinning to the δl pinning mechanism. The results shed light on the study of pinning mechanism for granular superconductors and is beneficial to the potential application of manipulating vortex pinning by regulation of intrinsic defects.

The sluggish reaction kinetics at the oxygen cathode is one of the important issues hindering the commercialization of the metal-air batteries. Although the noble metal can be used as the high-efficiency electrocatalyst to solve the problems to some extent, the high cost and scarcity of these noble-metal catalysts have limited their application in electrocatalysis. In this review, we discussed the mechanisms of the ORR and OER, and proposed the principles for the bifunctional electrocatalysts firstly, and then the state-of-the-art bifunctional catalysts, including carbon-based materials and transition-metal-based materials. On the basis of that, the self-supporting 3D noble-metal-free bifunctional ORR/OER catalysts were also discussed. Finally, the perspectives for the bifunctional electrocatalysts were discussed.

Using tailings as material to prepare glass-ceramic is an excellent way to achieve the resource utilization of solid waste. However, at present, researches on the solidification and migration of heavy metals are limited. Therefore, in this study, ten groups of samples were prepared by controlling sintering temperatures. The solidification, migration, and leaching behavior of non-volatile and volatile heavy metals were studied. The research showed that, with the increase of temperature, the properties of the samples were improved. Fe participated in the phase transformation and evolved into insoluble iron pyroxenes solid solution, while Pb was homogeneously distributed in the glass matrix of glass-ceramics. The leaching concentrations of Fe and Pb in the glass-ceramics were 0.055 mg/L ∼0.087 mg/L and 0.074 mg/L ∼0.140 mg/L, which were far below the threshold value. The results showed that heavy metals can be effectively solidified in glass-ceramics and have good environmental benefits.

The thermal stability, wear resistance and impact toughness of polycrystalline diamond compact (PDC) are the primary determining variables in determining the performance. The cobalt binder contributes significantly to the PDC's thermal stability and wear resistance. To increase the thermal stability of the PDC, this paper used electrolysis to remove the cobalt binder from the polycrystalline diamond (PCD) layer of the PDC with a diameter of 62 mm. The optimal process parameters for cobalt removal via electrolysis were determined by examining the electrolyte concentration, the electrolytic voltage, and the electrolytic time. The cobalt removal impact was evaluated using a scanning electron microscope (SEM), an energy dispersive spectrometer (EDS), an X-ray diffraction (XRD), and thermogravimetric analysis-differential thermal analysis (TG-DTA). In addition, the abrasion ratio of the PDC samples were tested. The experimental results indicated that the optimal electrolysis parameters for cobalt removal were obtained when the concentration of cobalt sulphate was 4 g/100 mL, the electrolysis voltage was 2.5 V, and the electrolysis time was 10 h; in this case, the cobalt removal rate from the PCD layer exceeded 80%, and the cobalt removal depth was 372 μm. TG-DTA analysis revealed that the thermal stability of PDC was significantly enhanced as a result of the initial graphitization temperature of the cobalt removal sample being increased from 1071 °C to 1113 °C, but the abrasion ratio rose by more than 20%. It was discovered that electrolysis may efficiently remove the cobalt binder phase from the PCD layer, therefore improving the thermal stability and wear resistance of PDC.

Defect-engineering in transition-metal-doped carbon-based catalyst plays an essential role for improving the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) performance. Herein, we report a ball-milling induced defect assisted with ZnCl2 strategy for fabricating defect-rich iron/nitrogen co-doped graphene-based materials (Fe-N-G). The substantial mechanical shear forces and the constant corrosion to the carbon matrix by ZnCl2 lead to the creation of abundant defects in graphene-based materials, which facilitates doping for heteroatoms. The defect-rich Fe-N-G catalyst with abundant Fe-Nx active sites displays excellent ORR performance. For OER, the over potential for Fe-N-G outperforms that of RuO2 in 1 M KOH at 10 mA cm−2. The Density Functional Theory calculations unravel that the impressive OER performance is attributable to the introduction of abundant defects. Additionally, the liquid and all-solid-state zinc-air batteries equipped with the prepared material as the air cathode demonstrate high power density, high specific capacity, and long charge–discharge stability. This work offers a practical method for manufacturing high-performance electrocatalysts for environmental and energy-related fields.

The volatile combustion and NO release characteristics of pulverized fuel (PF) flames in an optical flat-flame entrained-flow reactor were investigated by CH*/NO* chemiluminescence imaging. Pyrolyzed bituminous (PB) char with an ultralow volatile content (Vdaf≈10%) and a comparative coal sample of Shenhua (SH) bituminous coal with a high volatile content (Vdaf = 34.2%) were studied under different ambient O2 mole fractions (10%∼30%). The initiation of the combustion region of PB char occurs later than SH bituminous coal, owing to its low volatile contents, a slow devolatilization rate, and homogeneous-heterogeneous ignition/combustion mode. By measuring probed solid and gas samples, the conversion ratios of fuel-N to NO and the releasing ratios of volatile-N/char-N were determined in ignition process. Semi-quantitative NO release integral intensity and volatile combustion intensity results were obtained by integrating the NO* or CH* chemiluminescence intensity in the corresponding reaction region. The volatile combustion and NO release show good synchronous for Shenhua bituminous coal, which means that the NO releasing originated predominantly and owned higher conversion ratio from the volatile-N in the ignition region. The NO release integral intensity and NO emission of SH bituminous coal decreased with O2 concentration increased from 20% to 30%, which indicates that the enriched-O2 environment is beneficial for high volatiles bituminous to decrease NOx emission in ignition stage. For PB char, NO releasing originated predominantly from the char heterogeneous reactions of char-N in its ignition and combustion late stage.

Metallic foam was introduced as an interlayer to improve the performance of the brazed C/C composite-titanium alloy joint, and the interfacial microstructure and residual stress of the brazed joint were investigated. Compared with the brazed joint without foam, introducing foam interlayer could achieve the uniform bonding interface, and Ag-based solid solution (Ag(s,s)) became more dispersed and smaller in the center of the brazing seam. The thickness of reaction layer close to C/C composite side was less than 1 μm. Some Cu-based solid solution (Cu(s,s)) was detected, indicating that Cu foam still existed after brazing. The residual stress and its distribution calculated by finite element method (FEM), and the residual stress of the brazed joint decreased from 293 MPa to 228 MPa. The introduction of the foam interlayer could obtain homogeneous microstructure, change stress distribution, and improve mechanical properties of the brazed joints.

Electrochemical water or wastewater splitting is a sustainable development approach for both hydrogen generation and pollutant elimination. Herein, an N-engineering ultrathin bimetallic oxyphosphides nanosheets on Ni foam (CoNiOP/NF) as a multi-functional binder-free electrode was synthesized for hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and urea oxidation reaction (UOR). The catalytic activity of the composites could be improved through introducing N-doping via an in-situ transformation and heterogeneous metals by ion exchange. Both theoretical calculation and experimental investigations confirmed that electrons transferred from metal centers to anion at the interface, which was favor to accelerate the phase transformation to electrochemically active species and optimize the intermediates adsorption dynamics, thus providing greatly enhanced electrocatalytic activities. Assembled an electrolyzer using UOR replaced OER, it required only 1.42 V to achieve 50 mA cm−2 with long-term stability, 214 mV less than that required for HER‖OER. This work would be beneficial for the exploitation of non-noble metal-based electrocatalysts for simultaneous realization of energy-saving urea-assisted electrolytic hydrogen production and urea-containing wastewater purifying.

Summary Hydrogen has a remarkably flexible chemistry in oxides. We show that the introduction of H into simple TiO2 leads to greatly enhanced photocatalytic properties, and specifically yields a 60 times enhancement of photocatalytic hydrogen evolution activity over commercial rutile. The hydrogenated TiO2 (H-TiO2) is synthesized by a new one-step wet-chemistry approach yielding switchable defect via controlled annealing. As-prepared H-TiO2 has Ti-H bonds in the lattice from replacement of oxygen by hydrogen atoms. The Ti-H bonds are converted to oxygen vacancies by loss of H2O with Ar annealing. Oppositely, Ti-H defects are healed by Ti-O with O2 annealing. The strongly enhanced photocatalytic activity is associated with increased visible light absorption and effective separation of photogenerated carriers. This work provides a new and powerful approach for the preparation of hydrogenated titanium dioxide with switchable defect control, and striking improvement of photocatalytic activity.

SnO2 is one of the most promising catalysts for CO2 electroreduction. However, the intrinsic low electrical conductivity and weak CO2 adsorption and activation capability have rendered the reaction kinetically sluggish and inefficient.To surmount these hurdles, herein, W was incorporated into SnO2 nanosheets to modulate the electronic structures. Compared with the pristine SnO2, the p-band centre of W-doped SnO2 was elevated towards the Fermi level, accompanied by the reduction in the band gap and work function. As a result, both the CO2 adsorption and the electron transfer process were promoted, thus lowering the activation energy barrier for CO2 reduction. Benefitting from these, a maximum faradaic efficiency of 87.8% was achieved for HCOOH at -0.9 V vs. RHE. Meanwhile, the current density and energy efficiency approached 20.92 mA cm-2 and 60%, respectively. Such performances could sustain for 14 h without obvious fading and exceeded pristine SnO2 and most reported Sn-based catalysts. Tafel slope and reaction order analyses further suggested that the reaction proceeded following a stepwise electron-proton transfer pathway with the formation of CO2·- as the rate determining step. This work demonstarted the effectiveness of electronic structure tuning in promoting the catalytic performances of p-block metal oxides and contributed to the development of efficient catalysts for sustainable energy conversion and carbon neutrality.

The design of highly efficient noble-metal-free catalysts for fast hydrogenation of phenol to cyclohexanol is of great significance and quite challenging. Nickel-based Ni@C-T catalysts derived from Ni-MOF-74 with different pyrolysis temperatures (T) were prepared and characterized by various methods. The effect of T on the selective hydrogenation of phenol over Ni@C-T was studied. The results showed that metallic Ni is identified as the main activity site for the hydrogenation of phenol and the active metallic Ni was formed at the pyrolysis temperature higher than 400 °C. Ni@C-400 exhibited the best performance under mild conditions. The conversion of phenol reached 100% with a cyclohexanol selectivity of 100% under the reaction conditions of a temperature of 120 °C, a H2 pressure of 2.0 MPa and a time of 2 h, which are more excellent than those of reported catalysts. Furthermore, Ni@C-400 showed perfect reusability. The excellent catalytic performance of Ni@C-400 was associated with its high surface area and better dispersion of active sites due to the metal–organic framework.

Exploiting two-dimensional room temperature ferromagnetic materials is always a significant and valuable work. However, the actual number of satisfied materials with intrinsic ferromagnetism is very limited. Here, the van der Waals Cr4Te5 epitaxial films prepared by pulsed laser deposition technique were confirmed to hold ferromagnetic ordering state until to 300 K. We find that the Cr4Te5 films can easily achieve the epitaxial growth along a single orientation for the hexagonal Al2O3(0001) substrate. However, as for cubic SrTiO3(001) and multiphase structure Mica substrate, the Cr4Te5 films only show an uniaxial growth instead of epitaxial growth. Based on the investigation of electronic transport in metallic regime, it is revealed that the interaction of electronmagnon scattering only exists in the lower temperature region. Our work render two-dimensional vdW Cr4Te5 crystal a very promising material for developing practical spintronic nanodevices.

The selective separation of soluble and individual single-walled carbon nanotubes (SWCNTs) in aqueous solution is a key step for harnessing the extraordinary properties of these materials. Manipulating the strong van der Waals intertube interactions between the SWCNT bundles is very important in selective separation, which is a long-standing challenge. Here we reported the ability of redox polyoxometalate clusters to modulate the intertube π-π stacking interaction through electron transfer and achieved the diameter-selective separation of SWCNTs in a surfactant aqueous solution. The large-diameter SWCNTs concentrated at ∼1.3-1.4 nm were selectively separated when ∼1 nm clusters encapsulated within the tube cavity, and the dispersion of subnanometer ∼0.7-0.9 nm SWCNTs was boosted when clusters were adsorbed on the outer surface of small-diameter nanotubes. The mechanism of diameter-selective separation of SWCNTs associated with the size-dependent interaction between cluster-tubes and the steric hindrance effect of clusters was revealed by optical absorption and Raman spectroscopy. This simple method thus enables the selective separation of individual high-quality SWCNTs in aqueous solutions without harsh sonication with the potential for other separation applications.

The increasing demands for the management of hemostasis and tissue sealing drive the development of novel bioadhesives, which can overcome the disadvantages of conventional sutures such as additional tissue damage, increased infection probability, and body fluid/air leakage. Bioadhesives can form a protective layer with seamless adhesion between the injured tissues, thereby quickly closing the wound and creating appropriate microenvironments for wound healing. In this review, the recent advancement in bioadhesives made of natural macromolecules (polysaccharides and proteins, etc.) and synthetic macromolecules (cyanoacrylate, polyethylene glycol, polyurethane, etc.) have been summarized. The gelation and adhesion mechanisms that determine the bioadhesive properties and sealing functions are highlighted, and the current clinical applications of bioadhesives are also discussed. Based on these findings, a brief outlook on the future of bioadhesive is explored.

5,15-Bis(triisopropylsilyl)ethynyltetrabenzoporphyrin (TIPS-H2BP) gave a one-dimensionally extended columnar packing motif. The single crystal field-effect transistor of TIPS-H2BP exhibited clearly better hole mobility (2.16 cm2 V−1 s−1) than its metal complexes (ca. 0.1 cm2 V−1 s−1), with efficient charge transport through π–π stacking along the tetrabenzoporphyrin units.

Aqueous Zn-ion batteries (AZIBs) are promising candidates for large-scale energy storage owing to their intrinsic safety and low cost. However, the formation of Zn dendrite caused by uneven deposition on Zn anode severely impedes the lifespan of AZIBs. Herein, we propose a green and low-cost additive, nettle extract (NE), to guide the uniform Zn deposition via in-situ engineered zincophilic sites. We show by both experiments and theoretical calculations that the zincophilic molecules contained in NE can adsorb on Zn anode surface to offer more effective sites for Zn nucleation, thus effectively suppressing the dendrite growth. Significantly, the Zn||Zn symmetric cell with NE can stably cycle over 2200 h at 5 mA cm−2 with 5 mAh cm−2 capacity. A Zn||polyaniline/carbon felt full cell also gains 84.9% capacity retention after 1500 cycles. Our strategy of engineering zincophilic sites on Zn anode via plant extracts additives ushers in new possibilities to develop dendrite-free Zn anode.

In this article, a novel design method of dual-band and dual-state (DBDS) Doherty power amplifier (DPA) is proposed. Considering the actual parasitic parameters, the DPA can be designed by using the impedance transformation of saturation and back-off points at dual frequency bands of DBDS as well as second harmonic matching. The DBDS DPA for dual-band (DB) 5G application, i.e., 3.4 and 4.9 GHz band are designed and implemented, for the first time, by using metal-integrated and substrate-integrated suspended line (MI-SISL) technology, which has advantages of high performance and self-packaging. The fabricated DBDS DPA achieves the measured 44 and 43.2 dBm saturated power at 3.4 and 4.9 GHz bands, respectively. For the 3.4 and 4.9 GHz bands, the measured drain efficiency (DE) is 70.7% and 70.4% at peak power levels and 38% and 42% at a 6-dB output back-off, respectively. When driven by a 20- and 100-MHz modulated signal with 6-dB peak-to-average power ratio (PAPR), the adjacent channel leakage ratio is better than -27 dBc at operating frequencies. The average output power of 38 and 37 dBm with an average efficiency of 37.9% and 40.9% is achieved at 3.4 and 4.9 GHz, respectively.

In pursuit of environmental friendliness and high economic efficiency, renewable energy-driven selective acetylene semihydrogenation under ambient conditions is urgently requisite but remain a grand challenge. Herein, we explore single-atom nickel (Ni) dispersed N-doped carbon (SA-Ni-NC) as novel electrocatalysts for catalyzing selective acetylene semihydrogenation. In-situ electrochemical Raman and theoretical investigations reveal that weak π-adsorption of ethylene on individual Ni sites in SA-Ni-NC facilitates its desorption and thus avoids its overhydrogenation. Eventually, under pure acetylene flow, SA-Ni-NC exhibits a high ethylene Faradaic efficiency (FEethylene) of 91.3 %, and a large current density of −92.2 mA cm−2 at −0.6 V vs. reversible hydrogen electrode (RHE). Even in crude ethylene stream containing 1 % acetylene impurities (1×104 ppm), SA-Ni-NC still manifest a high acetylene conversion of 97.4 % with a large space velocity (SV) of 2.4×104 mL gcat–1 h–1 and a high turnover frequency (TOF) of 22.9 h−1 for each Ni atom.

The narrow bandgap Pb-Sn hybrid perovskite materials with lower toxicities and adjustable optical bandgaps provide the opportunity to construct high-efficiency perovskite solar cells (PerSCs). To solve the issues of the uncontrollable crystallization rate of Pb-Sn perovskite and easy oxidation of Sn2+, a β-diketone-based additive, N,N,N',N'-tetraphenylmalondiamide (TPMA), is introduced to coordinate with Pb2+ and Sn2+. The introduction of TPMA can improve the morphology of perovskite films and decrease the density of defect states, resulting in an enhanced power conversion efficiency of >20% and improved stability. The PerSC without encapsulation retains 94% of its initial efficiency after being stored for 1000 h in a nitrogen-filled glovebox and shows a lifetime of only 8% degradation after being continuously heated for 100 h at 80 °C. This work represents a new strategy of introducing a β-diketone ligand as an additive in precursor engineering for achieving efficient and stable PerSCs.

Aiming at the problem that power density and energy density are difficult to obtain simultaneously under low field, a novel composition (1-x)Na0·5Bi0·5TiO3-xBaZn1/3Ta2/3O3((1-x)NBT-xBZT) was designed and fabricated via solid-state methods. With the addition of BZT, the crystal lattice, structural symmetry, grain size, and dense degree were all increased proved by XRD, Raman, and Archimedes drainage method et al. Because of the enhancement of relaxor behavior, the x=0.10 sample displayed a high permittivity er of 2871±15% and a low dielectric loss tan δ ≤ 0.025 in the wide temperature range of 60–400 oC. This ceramic also showed maximum recoverable energy density Wd (2.07 J/cm3) with high efficiency η (71.5%) under a low field of 150 kV/cm. Moreover, pulse discharge testing proved that this ceramic possessed both a significant discharge energy density WD (0.96 J/cm3) and a record high power density PD (108.54 MW/cm3). This work provided a promising material for high power and energy applications.

3D-printing is an emerging technology that challenged wrought counterparts by one-step manufacturing for complicated biological devices. However, the material properties and surface features due to manufacturing parameters play an important role on the corrosion behaviour and influence the toxicity of the material as an implant. In this paper, the improvement of pitting potential was observed by electrochemical experiments as the result of grain refinement of DMLS 316 L at 200 W laser power. The ICP results verified the supressed release of toxic cations after the formation of the passive film with enhanced characteristics. However, the pores from DMLS 316 L have the potential to develop into pits when polarised above pitting potential, promoting the risk of using 3D-printed 316 L as implant materials.

The outstand flanges of aluminium alloy angles are sensitive to local buckling due to the low elastic modulus of material. To improve the sectional buckling stress, lips could be introduced to improve the stability behaviour of the outstand flanges. This paper presents an equilibrium approach and a simplified energy method for the local and distortional buckling of extruded aluminium alloy lipped angle columns. Closed form solutions for local buckling and distortional buckling are proposed. The equivalent flexural rigidity and torsional rigidity of the lip are two main factors affecting the sectional buckling behaviour. As distinct from double-sided symmetrical edge stiffeners, the bending of a single-sided edge stiffener can lead to in-plane compressive deformation of the adjacent flange. Based on the edge-stiffened flange model, the equivalent flexural rigidity of the lip is obtained from finite element (FE) analysis. To validate the proposed analytical methods, the elastic buckling coefficients of lipped angles with varying dimensions are obtained from eigenvalue buckling analysis. Lips of different thicknesses are considered to study the effect of torsional rigidity. Comparing with FE results, the proposed equilibrium approach shows excellent accuracy for both local and distortional buckling stresses. The closed form solution given by energy method can also well predict the sectional buckling stress. Finally, parametric studies are carried out to further investigate the effects of flexural and torsional rigidities of lips and the slenderness ratios of flanges on the elastic buckling behaviour. Some design remarks are concluded to provide valuable reference for the application of extruded aluminium alloy lipped angles in practice.

This study investigated sewage sludge stabilized/solidified with soda residue (SR) and ground granulated blast furnace slag (GGBS) after being dewatered with quicklime. The soaking durability test was conducted on the solidified sludge in tap water or landfill leachate. The toxicity and mineralogical characteristics of the solidified sludge were evaluated. The results showed that the unconfined compressive strength (UCS) of the solidified sludge met the strength requirement for use as a temporary cover material (≥ 50 kPa) for a short time (< 7 d). The solidified sludge had considerable soaking durability because UCS increased with the soaking time. The increase in the GGBS dosage improved the soaking durability of the solidified sludge. The UCS values of sludge solidified with 50% SR and 30% GGBS (sample S5G3) and with 80% SR (sample S8G0) after soaking in leachate for 60 d were 712.9 and 82.6 kPa, respectively. The X-ray diffraction (XRD) analysis indicated that hydration products, such as ettringite, Friedel's salt, gismondine, brushite, and hydrocalumite, contributed to the strength, soaking durability, and leachability performance of the solidified sludge. The inhibition of some hydration reactions and precipitation of ettringite and calcite on the surface of the specimens soaked in leachate led to a lower strength than that soaked in tap water. Sample S5G3 has the potential to be used as a filling or construction material, and sample S8G0 is suitable to be used as a temporary cover material in landfill.

Benefiting from the mature technology of ceramic injection molding, Fused deposition modeling based on highly-filled ceramic-polymer granular feedstocks has been showing great potential and advantage for fabricating 3D ceramics. Herein, 3D zirconia ceramics using granular feedstock were fabricated, and typical morphology, surface quality, and effect of the thermal accumulation on 3D structure were clarified. Typical morphology of printing steps on the surface were quantitatively characterized, and determined by the surface curvature and layer height of the printed structure. Aligned triangular pores were confirmed at the junction of the deposited filaments with elliptical cross-section morphology. Simple square plates with different size were used to illustrate the influence of thermal accumulation on the morphology of 3D structure. Small printing size increased the thermal accumulation during deposition, resulting in decreased printing quality caused by the secondary over-melting of former deposited layers. Except for the pores at the junctions, dense zirconia ceramics with uniform structure and smooth surface could be achieved. A low-cost and high-quality route for the preparation of 3D ceramics was demonstrated via FDM of highly-filled granular feedstocks.

The concrete-filled wide rectangular steel tubular (CFWRST) column is attracting more and more attention in engineering practice. The aspect ratio of CFWRST section is normally 2.0–3.0, which exceeds the limitation in existing studies, being less than 2.0. The finite element (FE) analysis has been widely used in investigating behavior of the concrete-filled rectangular steel tubular (CFRST) columns, where many parameters need to be calibrated using test results. This paper presents an investigation on behavior of CFWRST stub columns under axial compression using ABAQUS. On the basis of original constitutive model for confined concrete, the constitutive model for simulating CFWRST stub columns is presented, in which the involved parameters are calibrated using existing test results. The proposed model is verified to be suitable for simulating CFWRST stub columns, and it is considered to be capable of well extending the application range of the original model in CFRST columns with large aspect ratios. Subsequently, a total of 330 CFWRST columns are analyzed to investigate the effects of key factors on the behavior of CFWRST stub columns. Finally, based on the analyses, the limitation of width-to-thickness ratio of steel tube in CFWRST stub columns is presented, and solutions are also proposed for the ultimate axial load of CFWRST columns.

Eu3+-activated Sr3−xCaxLa(VO4)3 phosphors were fabricated via citric-acid-assisted sol combustion. Characterization of the Sr3−xCaxLa(VO4)3:Eu3+ samples with different concentrations of Ca2+ revealed a hexagonal crystal structure belonging to the R-3m space group. The amount of Ca2+ added (x) was controlled within 0 ≤ x ≤ 2 to yield high-purity phosphors. Scanning electron microscopy results showed that an increase in Ca2+ concentration resulted in a decrease in the particle size of Sr3−xCaxLa(VO4)3:Eu3+, with the shape gradually changing from nearly equiaxed to lath-shaped. The Sr2CaLa(VO4)3:Eu3+ phosphor (denoted as SCLVO:Eu3+) exhibited the strongest photoluminescence (PL) intensity at 618 nm among the samples under excitation of 394-nm near-UV (NUV) light. The study of Eu3+ doping concentration confirmed that Eu3+ could enter the lattice of the SCLVO matrix without altering its crystal structure. SCLVO:Eu3+ was found to strongly absorb 394 nm NUV light and 464 nm blue light. The optimal concentration of the Eu3+ dopant in the SCLVO host was 0.11, which resulted in the phosphor achieving an excellent PL intensity and a color purity of 98.68%. Tunable luminescence from the orange area (0.5280, 0.4522) of Commission Internationale de l'eclairage (CIE) to the red area (0.6313, 0.3650) was achieved by adjusting the concentration of Eu3+. Under 394 nm excitation, SCLVO:0.11Eu3+ phosphor has a quantum yield (QY) of 28.2% and excellent thermal stability with 0.383 eV activation energy. Consequently, White-light-emitting diode (WLED) based on SCLVO:0.11Eu3+ phosphor yielded a high color rendering index (CRI), low correlated color temperature (CCT), and CIE coordinates of 91.8, 5196 K, and (0.3407, 0.3612), respectively, under the 20 mA driven current. These results indicated the tremendous potential of SCLVO:0.11Eu3+ phosphors for application in WLEDs excited by NUV or blue light.

In this paper, a computer-aided polymer design (CAPD) framework with a stochastic optimization model is proposed for the design of perfluorinated sulfonic acid proton exchange membrane (PFSA-PEM) w...

Ultrasonic vibration technology has great potential to weaken hard rocks. Understanding the effect of ultrasonic vibration loading parameters is essential to accelerate the application of this technology in practical rock engineering. In the present work, three-factor mixed-level orthogonal ultrasonic vibration rock breaking tests were conducted to investigate the influence of the main loading parameters, including confining pressure, vibration frequency, and static force, on the damage of granite specimens. The individual and combined influences were analyzed according to the porosity increase and P-wave decrease of granite specimens using the variance analysis method. The results show that the combined effect of the static force and vibration frequency mainly promotes fatigue damage of specimens, that the confining pressure determines the damage behaviour and failure mode of specimens under ultrasonic vibration, and that the confining pressure and vibration frequency are the main factors that cause the fracture concentration in the upper part of specimens, an effect mechanistically driven by the obvious load energy attenuation. The research results provide theoretical guidance for the application of ultrasonic vibration technology.

Antimicrobial resistance in Gram-negative bacteria has become one of the leading causes of morbidity and mortality and a serious worldwide public health concern due to the fact that Gram-negative bacteria have an additional outer membrane protecting them from an unwanted compound invading. It is still very difficult for antimicrobials to reach intracellular targets and very challenging to treat Gram-negative bacteria with the current strategies. Here, we found that (o-(bromomethyl)phenyl)boronic acid was incorporated into poly((2-N,N-diethyl)aminoethyl acrylate) (PDEA), forming a copolymer (poly(o-Bn-DEA)) having both phenylboronic acid (B) and ((2-N,N-diethyl)amino) (DEA) units. Poly(o-Bn-DEA) exhibits very strong intramolecular B-N coordination, which could highly promote the covalent binding of phenylboronic acid with lipopolysaccharide (LPS) on the outer membrane of E. coli and lodge poly(o-Bn-DEA) on the LPS layer on the surface of E. coli. Meanwhile, the strong electrostatic interaction between poly(o-Bn-DEA) and the negatively charged lipid preferred tugging the poly(o-Bn-DEA) into the lipid bilayer of E. coli. The combating interactions between covalent binding and electrostatic interaction form a tug-of-war action, which could trigger the lysis of the outer membrane, thereby killing Gram-negative E. coli effectively without detectable resistance.

Electrolytic manganese anode slime (EMAS) contains many Mn resources, and efficient Mn leaching is the key to realizing its high-value utilization. In this study, the effects of Fe2+ concentration,...

Aqueous Zn anodes suffer from continuous side reactions and severe dendrite growth upon Zn plating and stripping, mainly due to the lack of an efficient protective layer. Herein, we report a facile...

Slow response and recovery kinetics is a major challenge for practical room-temperature NO2 gas sensing. Here, we report the use of visible light illumination to significantly shorten the response and recovery times of a PbSe quantum dot (QD) gel sensor by 21% (to 27 s) and 63% (to 102 s), respectively. When combined with its high response (0.04%/ppb) and ultralow limit of detection (3 ppb), the reduction in response and recovery time makes the PbSe QD gel sensor among the best p-type room-temperature NO2 sensors reported to date. A combined experimental and theoretical investigation reveals that the accelerated response and recovery time is primarily due to photoexcitation of NO2 gaseous molecules and adsorbed NO2 on the gel surface, rather than the excitation of the semiconductor sensing material, as suggested by the currently prevailing light-activated gas-sensing theory. Furthermore, we find that the extent of improvement attained in the recovery speed also depends on the distribution of excited electrons in the adsorbed NO2/QD gel system. This work suggests that the design of light-activated sensor platforms may benefit from a careful assessment of the photophysics of the analyte in the gas phase and when adsorbed onto the semiconductor surface.

In order to enhance the sensitivity, Pt coated ZIF-67 was proposed to detect humidity levels for human physiological signal monitoring. The proposed capacitive humidity sensors have superior sensitivity of 44.9 pF/%RH for ZIF-67 with 10 nm Pt, which is about 7.8 times of ZIF-67 with 2 nm Pt and 4490 times of pure ZIF-67. The specificity of water toward 7 interferential volatile organic compounds (VOCs) was analyzed for biomarker discrimination. The proposed sensor exhibits high stability and repeatability in five cycle tests. Normal, fast, deep, and slow breath were investigated to record reading, running, yoga, and sleeping activities, respectively. In addition, the low humidity level evaporated by human sweat on the skin surface can be detected with high sensitivity. This paper provides a highly sensitive humidity sensor for daily clinical monitoring and intelligent health applications.

Designing high-performance trifunctional electrocatalysts for ORR/OER/HER with outstanding activity and stability for each reaction is quite significant yet challenging for renewable energy technologies. Herein, a highly efficient and durable trifunctional electrocatalyst RuCoOx is prepared by a unique one-pot glucose-blowing approach. Remarkably, RuCoOx catalyst exhibits a small potential difference (ΔE) of 0.65 V and low HER overpotential of 37 mV (10 mA cm-2), as well as a negligible decay of overpotential after 200 000/10 000/10 000 CV cycles for ORR/OER/HER, all of which show overwhelming superiorities among the advanced trifunctional electrocatalysts. When used in liquid rechargeable Zn-air batteries and water splitting electrolyzer, RuCoOx exhibits high efficiency and outstanding durability even at quite large current density. Such excellent performance can be attributed to the rational combination of targeted ORR/OER/HER active sites into one electrocatalyst based on the double-phase coupling strategy, which induces sufficient electronic structure modulation and synergistic effect for enhanced trifunctional properties.

Nanolithography plays crucial roles in the miniaturization of dense integrated circuit, which extremely depends on innovative resist materials. Recently, metal-containing resists have been explored due to their higher short-wavelength photon absorption than traditional polymer resists. Herein, for the first time, the patterning performance of non-alkyl tin-oxo clusters has been evaluated. Meanwhile, the influence of structural characteristics on resolution and sensitivity has been investigated. To evaluate the surface ligand effect, three non-alkyl Sn10-oxo clusters with the same core were functionalized with pyrazole, 3-methylpyrazole and 4-methylpyrazole, respectively. Furthermore, another Sn14-oxo cluster with similar core configuration was also prepared using 4-methylpyrazole ligand to study the influence of Sn nuclearity. Spin-coating method was then applied to fabricate thin films of these non-alkyl tin-oxo clusters on Si substrate, which showed various thicknesses and roughnesses. More interestingly, electron beam lithography (EBL) patterning studies indicated that for the same Sn10 core, the 4-methylpyrazole-decorated clusters showed the best performance. As for the different cluster cores with the same 4-methylpyrazole ligand, the patterns of Sn10 with the higher ligand: Sn ratio are also better than those of Sn14. Finally, distinguishable 50 nm resolution was achieved by 4-methylpyrazole-decorated Sn10 at expose energy of 100 µC/cm2 which can be significantly improved by increasing expose energy to 1,000 µC/cm2 as confirmed by atomic force microscopy (AFM) images. This work not only opens the nanolithography applications of non-alkyl tin-oxo clusters, but also provides an effective structural methodology for improving their patterning performance in future.

It is of significance but remains a pivotal challenge to simultaneously enhance the strength and lightweight levels of porous structures. We provide an innovative strategy to improve the strength of porous structures with unchanged lightweight levels by applied composite materials. Selective laser melting (SLM) is convenient for integral forming of materials and structures. Hence, in this study, the research about the mechanical response of triply periodic minimal surfaces (TPMS) porous structures with 316L and composites fabricated by SLM was conducted. The compression test and finite element method (FEM) were used to characterize mechanical properties. The composite structures exhibit enhanced elastic modulus, yield strength, unvaried lightweight level and refined grain microstructure, which are difficult to realize for porous structures made by pure 316L materials. The elastic modulus, yield strength, plateau stress and energy absorption of composites were 3187.50, 67.73, 15.24 and 17.09 MJ/m3, respectively.