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An efficient method for catalyzing the ammoxidation of aromatic alcohols to aromatic nitriles was developed, in which a new heterogeneous catalyst based on transition metal elements was employed, the new catalyst was named Co-[Bmim]Br/C-700 and then characterized by X-ray photo-electronic spectroscopy, transmission electron microscope and X-ray diffraction. The reaction was carried out by two consecutive dehydrogenations under the catalysis of Co-[Bmim]Br/C-700, which catalytically oxidized the alcohol to the aldehyde, and then the aldehyde was subjected to ammoxidation to the nitrile. The catalyst system was suitable for a wide range of substrates and nitriles obtained in high yields, especially, the conversion rate of benzyl alcohol, 4-methoxybenzyl alcohol, 4-chlorobenzyl alcohol and 4-nitrobenzyl alcohol reached 100%. The substitution of ammonia and oxygen for toxic cyanide to participate in the reaction accords with the theory of green chemistry.

Activated carbon supported bimetallic Ni-based catalysts were prepared and applied in the selective hydrogenation of nitrocyclohexane (NCH) to cyclohexanone oxime (CHO). The characterization result...

The cyclopentanone and derivatives are a class of crucial fine chemicals for various industries and currently produced by conventional petrochemical synthetic routes. Here, we demonstrated a new synthetic approach to directly fabricate N-doped carbon nanotube (N-CNTs) networks with confined Co nanoparticles from Co2+-impregnated bulk g-C3N4 as high performance hydrogenation rearrangement (HR) catalyst to efficiently convert a wide spectrum of biomass-derived furanic aldehydes to the corresponding cyclopentanones in water under a record-low H2 pressure of 0.5 MPa and mild temperature. We unveiled a Co-catalysed bulk g-C3N4 decomposition/carbonisation CNTs formation mechanism. A new HR pathway was also unveiled.

Carbon-based nanomaterials are widely used in electro-catalysis because of their low cost, high conductivity and stability. However, their application towards selective electrochemical reduction of nitrogen to ammonia suffers from low activity and faradaic efficiency (FE). Here, we report a confined electrocatalysis strategy for enhanced ammonia production and FE in the electrochemical nitrogen reduction reaction (eNRR), by the construction of a carbon nanotube (CNT or NCNT) inserted porous metal–organic framework (MOF). The CNT/NCNT serves as the catalytic center and ensures an efficient pathway for electron conduction that is essential to electrocatalysis, while the general relative hydrophobicity within the MOF enriches the local concentration of N2 near the catalyst active sites, and more importantly suppresses the hydrogen evolution reaction (HER) to facilitate the FE. Among the systematically screened MOF and carbon nanotubes, NCNT@MIL-101(Fe) demonstrates the highest activity of 607.35 μg h−1 mgNCNT−1 and CNT@MIL-101(Fe) achieves the best FE of 37.28%. The significantly improved NRR performance of CNT@MOFs and NCNT@MOFs demonstrates the successful employment of confined catalysis in electrochemical reactions, which provides an alternative strategy for catalyst design in nitrogen fixation.

Design and synthesis of highly active and durable electrocatalysts toward oxygen reduction reaction (ORR) is of particular importance for proton exchange membrane fuel cells (PEMFCs), yet remains a grand challenge. Herein, we report the deposition of iron (III) porphyrin (FeP) on house-made Pt/C by rotary evaporation of the mixture of FeP and house-made Pt/C dispersed in chloroform, followed by pyrolysis at 650 °C in argon atmosphere. This approach led to the synthesis of new non-precious metal electrocatalyst (NPME)-Pt/C composites (Pt/C–FeP) with an average nanoparticle diameter of 3.1 ± 1.5 nm without aggregation. According to X-ray photoelectron spectroscopy (XPS), the binding energy of Pt 4f7/2 became larger due to the presence of pyrolyzed FeP. In addition, the electrochemically active surface area (ECSA) of Pt/C–FeP-650 is 65 m2/g less than that of house-made Pt/C (80.2 m2/g). This implies that the pyrolyzed FeP may have partially covered the surface of Pt nanoparticles and thus lowering the ECSA. Interestingly, the mass activity (MA) of Pt/C–FeP turns out to be 349.0 mA/mgPt @0.9 V vs. RHE, which is 2.6 times and 1.5 times of house-made Pt/C and commercial Pt/C, respectively. It is speculated that the electronic interaction and possible synergy between Pt and pyrolyzed FeP as NPME might have contributed to the ORR activity improvement despite of partial loss of ECSA. During accelerated durability tests (ADTs), the MA of Pt/C–FeP-650 degrades 64.3% inferior to commercial Pt/C (52.2%). The main reason likely arises from the degradation of pyrolyzed FeP, which is a bottleneck problem confronting NPMEs.

Butyrate has been shown to be effective in ulcerative colitis (UC). However, its oral administration is rare due to its rancid odour and unpleasant taste. In this study, the effect of a butyrate-releasing polysaccharide derivative, xylan butyrate ester (XylB), was evaluated in a dextran sodium sulphate (DSS)-induced UC model in C57BL/6 mice. Linear xylan was extracted from corn cobs. The C-2 and C-3 positions of the linear xylan were esterified with butyrate, forming XylB. The protective and therapeutic effects of XylB against UC were determined in a DSS-induced mouse model. The results showed that XylB treatments reversed the imbalance between pro- and anti-inflammatory cytokines. Moreover, XylB rebalanced the gut microbiota that interfered with DSS treatment and significantly decreased the relative abundance of the genera Oscillibacter, Ruminococcaceae UCG-009, Erysipelatoclostridium, and Defluviitaleaceae UCG-01. XylB increased butyrate content in the colon, upregulated G-protein coupled receptor 109A protein expression, inhibited histone deacetylase (HDAC) activity, and exerted anti-inflammatory activity through autophagy pathway activation and nuclear factor-κB (NF-κB) inhibition. XylB reduces inflammatory intestinal damage in mice, suggesting that it would be a potential drug for the treatment of UC and could be used to overcome the limitations of the oral administration of sodium butyrate.

Due to the heavy metabolic burden and low efficiency of microbial pure cultures during the biotechnological process for biochemicals production, researchers have focused on microbial cocultivation ...

Consolidated bioprocessing (CBP) has been considered as a cost-effective strategy for the efficient bioconversion of lignocellulosic biomass into valuable chemicals. Microbial consortium can comple...

Clostridium sp. strain NJ4 was successfully isolated and characterized, which exhibited a wide carbon utilization spectrum, including glucose, fructose, fructooligosaccharide, and Jerusalem articho...

TiO2-modified oxygen-functionalized activated carbon (TiO2@OAC)-loaded nickel-based catalysts (Ni/TiO2@OAC) were synthesized and applied in the hydrogenation of chloronitrobenzene (CNB) to chloroan...

Two-dimensional ferroelectric materials can maintain stable polarization with atomic layer thickness, and they have a wide range of technological applications in transistors, resistive memories, energy collectors and other multi-functional sensors for highly integrated flexible electronics. Domain evolution should be considered when 2d ferroelectric material-based devices are applied in a radiation environment, which may induce radiation damage and performance degradation. In this work, we investigate the domain evolution and photodetection performance degradation of α-In2Se3 nanoflakes induced by the total dose effect of 60Co γ-rays. The phonon modes change with an increase in total dose, while the domain structure changes in α-In2Se3 based transistors. Domain evolution may be one of the main reasons for the photoresponsivity degradation of these transistors. This investigation can provide a solid base for future research, and immediate applications in 2d ferroelectric material-based devices can be contemplated.

Polymeric membranes with high ionic conductivity and solvent molecule blocking capability are attracting considerable attention as separators for new-generation batteries adopting hybrid electrolytes. The performances of the membranes are closely dependent on their microstructures and functional groups. Here, we report the design and fabrication of a carboxyl-functionalized polymer-of-intrinsic-microporosity (PIM) membrane, which has optimal surface properties and microporous channels (∼0.8 nm) to permit cation (Li+ or Na+) transportation, while preventing solvent molecule penetration. Using a droplet-templating strategy, we create large pores on both surfaces of the PIM-membrane to improve its interfacial contact with electrolytes. The obtained membrane integrates good mechanical strength with high thermal and electrochemical stability, demonstrating a great potential for battery applications as a flexible separator. When intercalated with Li+, the membrane (PIM-1-COOLi) exhibits a remarkable Li+ conductivity in both aqueous (6.5 × 10−3 S cm−1) and organic (7.3 × 10−4 S cm−1) solutions, as well as a good solvent permeation resistance (19 μmol cm−2 min−1 at 10 Pa for H2O). Taking these advantages of the PIM-membrane, we are able to fabricate challenging batteries with hybrid electrolytes, such as Li–H2O2 and Na–H2O2 batteries (Li/Na anode with organic electrolyte and H2O2 cathode with aqueous electrolyte), into a flexible laminated form. The as-fabricated battery shows an excellent discharge performance, comparable to a model battery constructed with the commercial ceramic Li super-ionic conductor, but is more tolerant to mechanical treatment and harsh environment. Our study demonstrates that PIM represents a promising platform for developing flexible secondary batteries with hybrid electrolytes, which are particularly desirable for wearable and portable electronic devices.

In this paper, we report on the transport and magnetic properties of layered oxytelluride BiCuTeO polycrystals with slight mixed valence of Cu. The temperature-dependent electrical resistivity reveals degenerate semiconductor behavior (similar to metals). Under the action of an external magnetic field, the BiCuTeO polycrystal sample exhibits unsaturated magnetic resistance (MR) of about 8% at 2 K and 9 Tesla. The Hall resistivities show nonlinear behavior, suggesting the coexistence of both electrons and holes in the sample. When the temperature is decreased to around 110 K, the dominant carriers are changed from electrons to holes from the viewpoint of electrical transport, which is supported by the calculated temperature-dependent Fermi energy. Meanwhile, at low temperatures (

The vulnerability of current face recognition systems to presentation attacks significantly limits their application in biometrics. Herein, we present a passive presentation attack detection method based on a complete plenoptic imaging system which can derive the complete plenoptic function of light rays using a single detector. Moreover, we constructed a multi-dimensional face database with 50 subjects and seven different types of presentation attacks. We experimentally demonstrated that our approach outperforms the state-of-the-art methods on all types of presentation attacks.

Membrane electrode assemblies (MEAs) serve as the core units of polymer electrolyte membrane fuel cells (PEMFCs) and are regularly fabricated by painting a slurry of commercial Pt/C onto a membrane, leading to thick and disordered electrocatalyst layers (CLs). Herein, we report a photo-driven fabrication of MEAs with ultra-thin and ordered CLs by growing a monolayer of dendritic platinum spherical nanocrowns onto each side of a photocatalyst-modified membrane. This approach allows us to control the thickness and platinum loading of ordered CLs by simply varying the concentration of the platinum precursor under tungsten light irradiation. The resultant MEAs exhibit an excellent fuel cell power density of 1.01 ± 0.05 W cm−2 at a platinum loading of 53 ± 1.5 μg cmcathode−2. This exceptional activity likely arises from the nanostructured platinum crowns, efficient mass transport, and uniform reaction rate in the ultrathin (59 ± 12 nm thick) and ordered CLs according to electrochemical and theoretical investigations.

Doxorubicin (DOX) is widely used as a chemotherapeutic agent for liver cancer. However, its clinical applications are greatly restricted by its nonselective cytotoxicity. A novel magnetic prodrug, Fe3O4@DOX, was designed, synthesized and characterized, and Fe3O4 and DOX were connected by the peptide CGGAAN. The magnetic prodrug Fe3O4@DOX was successfully synthesized with average sizes of 95 nm and 322.5 nm by TEM (transmission electron microscopy) and Malvern Zetasizer instrument respectively. The maximum emission wavelength shifted from 594 nm for free DOX to 615 nm for conjugated DOX in the synthesized Fe3O4@DOX. Both free DOX and Fe3O4@DOX show strong cytotoxicity to legumain overexpressing PLC through apoptosis. Similarly, Fe3O4@DOX and DOX equally reduced tumor volume and induced cell apoptosis in tumor tissues, while the former significantly maintained body weight and extended the life of nude mice, therefore serving as a promising nanocarrier for liver cancer treatment.

Herein, the luminescence and photocatalysis, associated with the recombination and transportation of photon-induce charge carriers, are investigated in melilites-type Sr2MgSi2O7. It reveals that intrinsic traps cause photoluminescence and a weak afterglow. When N2 or N2 + H2 atmosphere was introduced in the synthesizing process, the traps are deepened. And more excited carriers are captured in traps, preventing their transportation to surface and thus improve the photoluminescence and reduce the photocatalytic ability. The Eu2+/Eu3+ doping serves as luminescent center and it seems to be an electron sink, which shunts electrons to recombination, instead of staying in traps or transportation to surface. Therefore, melilite synthesized in air without doping shows the highest catalysis efficiency in UV. And the one synthesized with Eu2+ doping shows the strongest photoluminescence, afterglow and thus thermoluminesccence. The H2-induced oxygen vacancies serve as a bridge to promote electrons to conduction band, improving the photocatalysis melilites in LED.

A novel thermometer, qualified with miniaturization, real-time monitoring, non-invasion, remote-control, and high spatio-temporal resolution, is urgently required for temperaturedetecting of sub-micrometric objects and in specific harsh conditions. Herein, we report an adaptable dual-mode optical thermometry platform LiTaO3:Ti4+, Eu3+@PDMS. A proof-of-concept implementation based on fluorescence thermometer (FT) demonstrates outstanding temperature sensing performance with excellent reversibility. The maximum Sa and Sr are as high as 0.671 and 5.425% K−1, respectively, with minimal temperature resolution of 0.14 K. Whilst, the maximum Sa and Sr based on lifetime thermometer (LT) are determined to be 0.122 and 3.637% K−1, respectively, with superior temperature resolution of 0.027–0.058 K. Finally, flexible phosphor films and 3D micro-rod arrays with handily encrypted information are fabricated for the unclonable multi-modal/multi-dimensional anti-counterfeiting application by exploiting light, temperature and time-domains as the “key” to decrypt the “locked” ciphertext, which indicates the promising prospect in temperature sensing and anti-counterfeiting. This work not only paves a way for developing novel spatial/temporal dual-mode real-time thermometer based on synergetic luminescence of lanthanide (Ln) and transition-metal (TM) ions with high temperature sensitivity and resolution, but also opens a new “window” for extending the thermometer as a flexible device in advanced multi-mode multi-dimensional high-level secure anti-counterfeiting.

A thin slice-like Co3O4/N-doped graphene (Co3O4-N-Gr) was prepared through a hydrothermal reaction. The as-prepared Co3O4-N-Gr displayed an onset potential and half-wave potential of 0.98 and 0.86 V, which were 40 and 80 mV larger than that of Pt/C (0.94 and 0.78 V), while its Tafel slope (31.4 mV dec−1) was much lower than Pt/C (44.7 mV dec−1). Moreover, the current density retained 96.25% after working for 6000 s and had no change after adding methanol. These suggest that the Co3O4-N-Gr is promising as an efficient electrocatalyst for oxygen reduction reaction (ORR) in alkaline medium when compared with Pt/C and other reported non-precious catalysts.

The cement augmentation technique using poly(methyl methacrylate) (PMMA) is considered to be the most effective method for fixation of osteoporotic fracture because of its outstanding mechanical properties. However, the low bio-degradation of PMMA, which hinders bone ingrowth, limits it potential for a broad range of applications. Previous studies have shown blending β-tricalcium phosphate (β-TCP) with PMMA was able to improve the osteoconduction while the material still suffered poor mechanical properties due to the poor compatibility between two components. In this study, we explored the use of hydroxyethyl methacrylate (HEMA) as a compatibilizer for improving the affinity of TCP/PMMA blends system. The resultant TCP/HEMA/PMMA(THP) composite cements exhibited similar setting properties to PMMA cement but much better mechanical properties than composite systems without HEMA as a compatibilizer. No cytotoxicity or hemolysis was observed in the THP bone cement system by biochemical assays. Bone ingrowth was significantly improved at 12 weeks. The reinforced pull-out strength of screws was observed at 4, 8, 12 weeks through in vivo studies performed on rabbit femurs. The THP system, as an injectable bone cement material, shows great potential for use in the cement augmentation technique.

SrTiO3 is a promising candidate photocatalyst for overall water splitting. Loading suitable cocatalysts, such as NiOx, the mixture of Ni and NiO, remarkably improve the photocatalytic activity. However, spatial locations and functions of components in NiOx/SrTiO3 are under debate. Here, using first-principles density functional theory (DFT) calculations, we investigate the initial growth of Nin (n = 1–4) and (NiO)n (n = 1, 2 and 4) clusters on stoichiometric (100) surfaces of SrTiO3, and explore interfacial and electronic structures of composite photocatalysts. It is found that Nin clusters are easier to undergo aggregation on SrO-termination than on TiO2-termination. The adsorption of Nin cluster on (100) surfaces elevates the Fermi level towards the conduction band, which may benefit the occurrence of hydrogen evolution reaction. The structural similarity between (NiO)n cluster and surface has an essential effect on the most stable adsorption configuration. For (NiO)n/SrTiO3 systems, the occupied states of (NiO)n cluster well overlap with those of (100) surfaces in the valence band maximum, which is in favor of the separation of photogenerated electrons and holes to SrTiO3 support and (NiO)n cluster, respectively. The detailed DFT analysis provides important insights into the growth of NiOx on surfaces of SrTiO3 and presents an explanation on the different models of NiOx/SrTiO3 photocatalyst proposed by experimental groups. Our calculations build a basis for further investigations on the mechanism of photocatalytic water-splitting reaction in NiOx/SrTiO3 composite system.

We report the synthesis of β-palladium hydride nanodendrites (PdH0.33 NDs). The uniform PdH0.33 NDs are 36.3 ± 5.0 nm in diameter and selectively expose (111) planes decorated with (221) and (331) high-indexed steps. The PdH0.33 NDs show a high mass activity of 0.719 A/mgPd at 0.9 V (vs. reversible hydrogen electrode-RHE) toward alkaline oxygen reduction reaction (ORR), which is 3.7 and 6.3 times that of commercial Pt/C and house-made Pd/C, respectively. This study exemplifies the possibility of using special morphology and lattice H to modify the strain and electronic effect of metal for the optimization of functionalities. Keywords: Palladium hydride, Nanodendrites, Oxygen reduction reaction, Oxygen adsorption energy

This paper demonstrates that a highly thermal stable and tunable-luminescence phosphors Y3Al2Ga3O12: Tb3+, Eu3+ with efficient energy transfer, which is prepared by the high-temperature solid-state reaction. First-principles method is performed to analyze the electronic structures, band structure, density of states and formation energy of Y3Al2Ga3O12: Tb3+, Eu3+. For high luminescence output, Y3-xAl2Ga3O12: xTb3+ and Y3-yAl2Ga3O12: yEu3+ with high concentration quenching (x = 0.5 and y = 0.7) are achieved. The effect of energy transfer from Tb3+ to Eu3+on emission color tuning and luminescence thermal stability is studied. The energy transfer efficiency from Tb3+ to Eu3+ reaches as high as 74.2% and emission color can be tuned from green, yellow and red by adjusting the ratio of Tb3+/Eu3+. What's more, Y3Al2Ga3O12: Tb3+, Eu3+ phosphor exhibits a good thermal stability, of which emission intensity still keeps 60% at 150 °C.

Consolidated bioprocessing (CBP) is a promising approach for hydrogen production from lignocellulose owing to its lower cost and higher efficiency. In this study, the newly isolated theromphilic Thermoanaerobacterium sp. strain F6 exhibited the capability of direct utilization of various hemicellulosic and cellulosic materials for hydrogen production, including xylan, Avicel and filter paper etc. Especially, the maximum cumulative hydrogen production reached 370.7 mmoL/L from 60 g/L of xylan. In addition, natural lignocellulosic materials, such as corn cob and sugarcane bagasse without any hydrolytic pretreatment could also be directly utilized as the sole carbon source for hydrogen production. 1822.6 and 826.3 mL H2/L of hydrogen were produced from corn cob and sugarcane bagasse, respectively. The high hydrogen production from cellulosic and hemicellulosic materials were both benefit from its efficient secretion of hydrolytic enzymes. Thus, Thermoanaerobacterium sp. strain F6 is a potential candidate for effective conversion of lignocellulose to hydrogen through CBP.

Luminescent material Ca2Ba3(PO4)3F:Eu2+ displays green emitting in the range of 400–700 nm, which is ascribed to the 4f65d1 →4f7 transition of Eu2+ ions. Amazingly, the body color of the samples can be changed between colorless and green upon alternative UV and visible light irradiation/heating treatment with robust fatigue resistance due to photochromism. The photochromic effect strongly depends on the Eu2+ doping concentration. After remote-controlled short-UV irradiation, the overall Eu2+ emission intensity presents a significant decrease, and inversely, exhibits an increase to the initial level after illuminated by longer wavelength light or heat treatment. Moreover, the fluorescence lifetime also can be regulated reversibly, of which the regulation degree depends on the short-UV irradiation and longer wavelength illumination time/heating temperature. A schematic diagram based on energy levels is proposed to illustrate the photochromism mechanism.

A new near-infrared phosphor Mg4Ga4Ge3O16: Cr3+ with multi-photo-functionalities has been developed. Such phosphors can act as luminescent down-shifting materials converting UV and visible photons into NIR light (600–850 nm). UV irradiation induced strong NIR long persistent luminescence (LPL) can persist for more than 10 h. With the prolonged decay time, the extinguished NIR LPL can be rejuvenated by external photo stimulus including not only 980 nm light but also visible light. Such NIR photostimulated persistent luminescence (PSPL) presents separated write-in and read-out wavelength ranges. Meanwhile, photochromism (PC), that the material surface undergoes reversible change between white/pale green and ronbrown when triggered alternatively by UV and visible irradiation/heating, was also observed. Several recycle measurements demonstrate the robust fatigue resistance of PC property. Owning to the multi-photo-functionalities of Mg4Ga4Ge3O16: Cr3+, the fabrication of flexible phosphor membranes endows their application for optical information storage and repeatable optical recording. The electron motion in traps was studied by thermoluminescence (TL) and the color center formation was verified with electron spin resonance (ESR) spectra, based on which an energy level diagram was proposed for the illustration of the multifunctional mechanism. The revealing of multi-photo-functional mechanism and fabrication of flexible phosphor membranes may promote the development of a universal design principle for further study.

Dicyandiamide derived graphitic carbon nitride (g-C3N4) was chemically intercalated by concentrated H2SO4 firstly, followed by a rapid heating treatment. Molecules between the stacking layers of g-C3N4 produced an explosive effect upon rapid heating to thermally exfoliate g-C3N4 into porous structures. The appearance color of g-C3N4 changed from light yellow to grey after heating treatment indicating the enhanced light absorption properties, which were identified by the UV–vis absorption test. In addition, photoluminescence intensities of porous g-C3N4 were obviously suppressed compared to those of bulk g-C3N4 samples, indicating the prevention of the recombination process of photogenerated electron-hole pairs. As a result of these simultaneous modifications in texture, optical and electronic properties, the photodegradation kinetics of crystal violet on the catalyst surface can be improved by 4.75 times.

Single-doped color tunable phosphors Na3Sc2-xAlx(PO4)3-y(BO3)y:Eu2+ are synthesized by conventional high temperature solid-state reaction method. Both the excitation and emission spectra of Eu2+ in Na3Sc2(PO4)3 can be effectively tailored by equivalent substitution. The equivalent cation substitution of Sc3+ by Al3+ and unit substitution of (PO4)3- by (BO3)3- results in the significant distortion of the local environment neighboring the Na O polyhedral, which enables the modulation of Eu2+ occupation on three kinds of Na sites. Besides the original occupation of Na1 site by Eu2+, equivalent cation and unit substitutions open a way for Na2 and Na3 sites to be occupied by Eu2+ ions, which leads to the significant widening of the Eu2+ emission spectrum to full-color. The mechanism of widening the Eu2+ emission spectrum is elucidated. Furthermore, the different thermal stability behaviors that Eu1 emission is better than that of Eu2 and Eu3 ions are also discussed.

A series of phosphors Ca14Zn6Ga10O35:Mn4+, Ln3+ (Ln = Nd, Yb, Er) have been prepared by conventional high temperature solid-state reaction. Mn4+ single doped Ca14Zn6Ga10O35 shows deep red emitting, and it can obtain NIR emission when co-doped with Ln3+ in Ca14Zn6Ga10O35:Mn4+ via an efficient energy transfer from Mn4+ to Ln3+. This process mainly is attributed to the dipole-dipole interaction mechanism. Visible-NIR to NIR down-shifting is realized via the energy transfer from Mn4+ to Ln3+ ions. Reversely, the green emission of Er3+ can be observed upon 980 nm light excitation, and the red emitting of Mn4+ appears in Mn4+ and Er3+ co-doped Ca14Zn6Ga10O35 phosphors through the up-converted energy transfer from Er3+ to Mn4+. Two-photon processes are required to populate the 2H11/2, 4S3/2 and 4F9/2 excited states of Er3+. The dual-mode luminescence mechanism, including energy transfer from Mn4+ to Ln3+ and up-conversion energy transfer from Er3+ to Mn4+, has been discussed in detail.

Blue-colored aluminum pigments with double layer structure Al@SiO2@(CuPc-SO3)2Ba were prepared by a two-step process of surface modification. The aluminum pigments were firstly encapsulated using tetraethoxysilane (TEOS) and silane coupling agents as precursors. A kind of water-soluble organic dye CuPc-SO3H was immobilized onto the surface of Al@SiO2 by liquid-phase deposition. SEM, FTIR, XRD and XPS were used to characterize the surface morphology and chemical structure of the Al@SiO2@(CuPc-SO3)2Ba pigments. The effect of different silane coupling agents and optimum conditions on the two-step surface modification were studied. The corrosion results showed that the coupling agent with long alkyl chain could significantly improve corrosion resistance of aluminum pigments. Chromatism analysis indicated that the glossiness of Al@SiO2@(CuPc-SO3)2Ba pigments decreased slightly and showed angle-dependent optical effect.

The bismuth oxychalcogenide compounds contain many different kinds of materials, such as Bi2O2X and Bi2OX2 (X = S, Se, and Te). These materials have different but similar layered crystal structures and exhibit various interesting physical properties. Here, we have theoretically investigated their Raman and infrared spectra by first principles calculations based on density functional theory. It is found that in Bi2O2Se the calculated frequency of the A1g Raman active mode is in good agreement with the experimental measurements while the other three modes are ambiguous or not observed yet. The Raman and infrared spectra of other materials are also presented and need further confirmation. Our work provides the structural fingerprints of these materials, which could be helpful in identifying the crystal structures in future experiments.

Dispersive solid phase extraction (d-SPE) is a preponderant methodology featuring direct contact and interaction between adsorbents and analytes. Herein, we used the porous metal–organic framework (MOF) MIL-101(Cr) as a d-SPE adsorbent for pretreatment of edible oil samples and determination of benzo[a]pyrene (BaP). The samples after treatment are applied to determination by high performance liquid chromatography coupled with a fluorescence detector (HPLC-FLD). We optimized the type and dosage of the MOF, diluent and eluent. Under the optimized conditions, this method gave a linear calibration curve for the determination of BaP in the range of 1–30 ng mL−1 (R2 = 0.9958) and the relative standard deviation (RSD) ranged from 1.07 to 8.14% (n = 6). The limit of detection was 0.19 ng mL−1 (S/N = 3) and the recoveries from different types of spiked oil samples were between 88.8 and 118.8%. Compared with conventional methods, the MOF-based d-SPE reduces organic solvent consumption and simplifies operation, which provides potential for application in extraction of hydrophobic targets from oil complexes.

Urea/urine as a renewable energy source is attracting extensive attention, which represents a promising prospect toward ensuring a clean environment and energy utilization. We herein report a new Li-urea battery architecture with organic and aqueous hybrid electrolytes. The concept of urea decomposition was first proposed in a Li-fuel battery. This low-cost portable device provides a new potential for power generation in the desert or remote regions.

Aqueous organic redox flow battery (AORFB) is one of the attractive technologies for renewable energy storage. The electronic effect or steric effect of the functional groups are commonly under discussion to screen the appropriate organic electrolytes for AORFBs. However, the role of structural reorganization on the electron transfer process of organic electrolytes in AORFBs is still not clear. In this work, we study the electrochemical properties of three bipyridine derivatives as organic electrolytes for AORFBs. The influence of structural reorganization on the electron transfer is investigated by changing the type and position of the functional groups of the bipyridine derivatives. Density functional theory (DFT) calculation reveals that the molecular structures of three molecules have a noticeable difference due to the steric effect of the functional groups. Furthermore, the rate constants of 1,1′-ethylene-2,2′-bipyridinium dichloride and methyl viologen are significantly higher than that of 1-methyl-2-(1-methylpyridin-1-ium-2-yl)pyridin-1-ium dichloride due to the much lower reorganization energy. As a result, a single battery using 1,1′-ethylene-2,2′-bipyridinium dichloride as the organic electrolyte shows excellent cell performance with the energy efficiency of 67.18% and excellent cycling stability with a capacity retention of 99.95% per cycle at the current density of 100 mA cm−2.

In recent years, systemic hypothermia has taken the spotlight for its use in spinal cord injury (SCI) research fields, but detailed molecular mechanisms are still not fully understood. In this study, we use an online-electrochemical system (OECS) to in vivo continuously monitor the ascorbate of the rats' spinal cord. We find that the basal level of ascorbate in rat spinal cord is 1.85 ± 0.88 μmol L

The formation of charge density wave (CDW) is attributed to Fermi-surface nesting in textbooks, but this common paradigm is challenged by recent studies that reveal the pronounced effects of electron-phonon interaction and defects. Transition-metal dichalcogenide $\mathrm{Ta}{\mathrm{Te}}_{2}$, being a prototype of charge density wave at around 170 K, is an ideal playground for exploring the mechanism of CDW. In this work, we reveal the subtle effect of defects on the CDW through studying a series of $\mathrm{Ta}{\mathrm{Te}}_{2\ensuremath{-}\ensuremath{\delta}}$ ($\ensuremath{\delta}=0.028\ensuremath{-}0.123$) crystals. Transport measurements show that $\mathrm{Ta}{\mathrm{Te}}_{1.972}$, being close to the stoichiometric compound, have a resistivity-kink feature (fingerprint of CDW) around 160 K along both $a$- and $b$ axes; $\mathrm{Ta}{\mathrm{Te}}_{1.933}$ only has a resistivity-kink feature along the $b$ axis. Remarkably, the resistivity kink completely disappears in $\mathrm{Ta}{\mathrm{Ta}}_{1.877}$. Raman spectroscopy not only confirms the corresponding structural phase transition, but also verifies decreased electron-phonon interaction at the \ensuremath{\Gamma} point of the Brillouin zone from $\mathrm{Ta}{\mathrm{Te}}_{1.972}$ to $\mathrm{Ta}{\mathrm{Te}}_{1.933}$ based on analysis of theoretical Fermi surface of 1 ${T}^{\ensuremath{'}}$ phase of $\mathrm{Ta}{\mathrm{Te}}_{2}$ before CDW phase transition. We propose that the CDW of $\mathrm{Ta}{\mathrm{Te}}_{2\ensuremath{-}\ensuremath{\delta}}$ ($\ensuremath{\delta}=0.028\ensuremath{-}0.067$) along the $a$ axis is mainly due to electron-phonon interaction, while CDW along the $b$ axis is the synergetic effect of Fermi-surface nesting and electron-phonon interaction; if dopant concentration is high enough $(\ensuremath{\delta}=0.123)$, CDW is completely quenched by disorder induced by doping. Our study reveals the subtle effects of doping on CDW, and may give more hints on the interplay between CDW and high-temperature superconductor in the doped Mott insulators.

The interfacial charge transfer from the substrate may influence the electronic structure of the epitaxial van der Waals (vdW) monolayers and thus their further technological applications. For instance, the freestanding Sb monolayer in puckered honeycomb phase ({\alpha}-antimonene), the structural analog of black phosphorene, was predicted to be a semiconductor, but the epitaxial one behaves as a gapless semimetal when grown on the Td-WTe2 substrate. Here, we demonstrate that interface engineering can be applied to tune the interfacial charge transfer and thus the electron band of epitaxial monolayer. As a result, the nearly freestanding (semiconducting) {\alpha}-antimonene monolayer with a band gap of ~170 meV was successfully obtained on the SnSe substrate. Furthermore, a semiconductor-semimetal crossover is observed in the bilayer {\alpha}-antimonene. This study paves the way towards modifying the electron structure in two-dimensional vdW materials through interface engineering., Comment: 18 pages, 4 figures

A series of broadband blue-green phosphors Rb0.5+yNa1.5−y(Li3SiO4)2:xEu2+ (0 ≤ y ≤ 0.4, 0.01 ≤ x ≤ 0.08) were synthesized by the high-temperature solid-state reaction. The powder X-ray diffraction was employed to explore the crystal structural evolution from RbNa3(Li3SiO4)4 to RbNa(Li3SiO4)2 with the increasing of Rb+. The spectra show the optimized composition was determined as y = 0.4. The luminescence, lifetime decay curves and thermal steadily spectra of Rb0.9Na1.1(Li3SiO4)2:xEu2+ phosphors were investigated in detail. The phosphor of Rb0.9Na1.1(Li3SiO4)2:Eu2+ shows suitable visible spectra (450–550 nm, cover the blue and green regions), excellent thermal quenching (104%@150 °C of the initial integrated intensity at room temperature under 396 nm excitation) and broad excitation spectrum (320–450 nm). Finally, a commercial near-UV LED devices (395 nm) were fabricated with the Rb0.9Na1.1(Li3SiO4)2:Eu2+ phosphor as blue-green and commercial red phosphor CaAlSiN3:Eu2+ with a warm color temperature of 3104 K and a color rendering index of 91.8. This result indicated that Rb0.9Na1.1(Li3SiO4)2:Eu2+ may be a promising blue-green phosphor for indoor lighting.

Five patients with segmental irregular-shaped bone defect of the femur were recruited in this study from 2017.12 to 2018.11. All patients were treated by customized design and 3D printed micro-porous prosthesis. And the procedure was divided into stages: radical debridement and temporary fixation (the first stage); the membrane formation and virtual surgery (intervening period for 6-8 weeks); definite reconstruction the defects (the second stage). Routine clinical follow-up and radiographic evaluation were done to assess bone incorporation and complications of internal fixation. The weight-bearing time and the joint function of the patients were recorded. The patients were followed up for an average of 16.4 months. The average length of bone defect and the distal residual bone was 12 cm and 6.5 cm. The average time of partial weight-bearing and full weight-bearing was 12.7 days and 2.6 months. X-ray demonstrated good osseous integration of the implant/bone interface. No complications occurred such as implant loosening, subsidence, loss of correction and infection. At the last follow-up, Harris score of hip joint was excellent in 2 cases, good in 2 cases, fair in 1 case; HSS score of knee joint was good in 4 cases, middle in 1 case. From our study, we concluded that meticulous customized design 3D printed micro-porous prosthesis combined with intramedullary nail may be a promising and an alternative strategy to treat metaphyseal segmental irregular-shaped femoral bone defect, especially for cases with massive juxta-articular bone loss.

Steel slag, a by-product of steelmaking, imposes lots of negative impacts on the environment. For alleviating negative impacts, more and more experiments have been carried out to explore the application possibility of steel slag. The purpose of this study is to explore the feasibility of steel slag being applied in induction healing asphalt concretes to replace coarse and fine aggregate. Surface texture and pore sizes of steel slag were firstly tested, and then steel slag and basalt asphalt mixtures modified with steel fibers were prepared. Moisture susceptibility, dynamic stability, mechanical property, thermal property, induction heating speed, natural cooling speed and healing property of the asphalt mixtures were evaluated. Results showed that steel slags had more obvious holes in the surface while the surface area is much larger than that of basalt. Furthermore, steel fibers and steel slag both have dynamic stability, and steel fibers contribute to increased moisture resistance while steel slag is not. Steel slag asphalt concrete showed better mechanical property and better capacity to store heating. Steel slag asphalt mixtures had a similar heating speed to basalt asphalt mixtures but a significantly slower cooling rate. Finally, the induction healing test and CT scanning test demonstrated that steel slag asphalt mixtures had a similar healing ability to basalt asphalt mixtures. It can be concluded that steel slags have the potential to replace the natural aggregates to be applied in induction heating self-healing asphalt concretes.

Surface protection has been accepted as an effective way to improve the durability of concrete. In this study, nanosilica (NS) was used to improve the impermeability of cement-fly ash system and this kind of material was expected to be applied as surface protection material (SPM) for concrete. Binders composed of 70% cement and 30% fly ash (FA) were designed and nanosilica (NS, 0–4% of the binder) was added. Pore structure of the paste samples was evaluated by MIP and the fractal dimension of the pore structure was also discussed. Hydrates were investigated by XRD, SEM, and TG; the microstructure of hydrates was analyzed with SEM-EDS. The results showed that in the C-FA-NS system, NS accelerated the whole hydration of the cement-FA system. Cement hydration was accelerated by adding NS, and probably, the pozzolanic reaction of FA was slightly hastened because NS not only consumed calcium hydroxide by the pozzolanic reaction to induce the cement hydration but also acted as nucleation seed to induce the formation of C-S-H gel. NS obviously refined the pore structure, increased the complexity of the pore structure, and improved the microstructure, thereby significantly improving the impermeability of the cement-FA system. This kind of materials would be expected to be used as SPM; the interface performance between SPM and matrix, such as shrinkage and bond strength, and how to cast it onto the surface of matrix should be carefully considered.

Ball milling (BM) is utilized to fabricate a composite photocatalyst composed of g-C3N4 material and ZnPc, which traditionally has been a sensitizer in TiO2 based solar cells yet usually having severe agglomeration problem. X-ray diffraction and FTIR results demonstrate that ZnPc has been immobilized onto g-C3N4 surfaces and that the inter-molecular bonds were also destroyed to a large extent, leading to improved dispersion of ZnPc. Further diffuse reflectance and photoluminescence characterization indicated distinct extended spectral response region at 600–700 nm as well as prohibited carrier recombination of the g-C3N4/ZnPc composite. When utilized as a photocatalyst, the properties of g-C3N4/ZnPc composites in the degradation of RhB were 3.1, 1.8 and 4.3 times higher than those of the pristine, ball-milled pure g-C3N4 and g-C3N4&ZnPc. By adding some scavengers, the main active species involved in the photocatalytic process were identified as •O2−. The improved photocatalytic performance could be ascribed to well-matched band gaps between ZnPc and g-C3N4, extended light-responsive range as well as the better ZnPc dispersion upon g-C3N4 surfaces.

AISI 304 metastable austenite stainless steel was cold rolled under cryogenic temperature and transformed into martensite completely, after reverse transformation by annealing, bulk nano/ultrafine grained material was obtained. The material’s microstructure was observed by TEM, and the corrosion resistance was studied by polarization curve, EIS, and Mott-Schottky plot. Results showed that samples cold rolled at −120 °C had an equiaxed microstructure and displayed the best corrosion performance. The distinctive polarization curve shape indicated that its passive film had a peculiar feature, and the M-S plot showed its abnormal semiconductor character. XPS measurements are used to directly characterize the composition of passive film formed on specimens. Heterogeneous microstructures might help with the improvement on corrosion resistance of the nano/ultrafine grained stainless steel.

As a representative of low-temperature direct biomass fuel cells, direct ascorbic acid fuel cells (DAAFCs) carry many advantages, including renewable fuel, easy transportation and storage, and high safety. However, a major challenge of DAAFCs confronting us is relatively low power density. Herein, to deal with this challenge, we treat carbon black (BP 2000) with nitric acid at an optimal concentration (4 M), which is further employed as anodic electrocatalyst for AA oxidation with improved hydrophilicity. Consequently, hydrophilic AA molecules can more readily access the surface of the carbon electrocatalyst and donate electrons. Furthermore, the electrocatalytic effect of acid-treated carbon for AA oxidation reaction is quantitatively evaluated by the determination of activation energy, which has not been assessed prior to this study. In a similar way, nitric acid treatment is also applied to gas diffusion layer (GDL) at the anode side. In addition, Nafion content in anodic electrocatalyst layer, single cell operating temperature, and hot pressing conditions for the fabrication of membrane electrode assembly (MEA) as well as membrane thickness are also optimized. A maximum power density of 31 mW cm−2 is eventually attained at 80 °C with anode ionomer content of 9.2% and hot pressing at 130 °C and 6 MPa for 2 min. This power density is 1.72 times of that reported previously with carbon black as the anode electrocatalyst.

With the objective of adjusting rough-body foaming and thickening stability of carbide slag based high utilization solid-wastes autoclaved aerated concrete (HUS-AAC) during pre-curing process, the effect of binding material composition and admixture on slurry, physic-mechanical property and hydration products were investigated to put forward an appropriate slurry performance adjustment scheme. Slurry properties include slump flow, time-dependent rheological, and gas foaming properties. Slump flow was conducted to estimate the initial fluidity of primary slurry with different ordinary portland cement 42.5 (OPC42.5) content and sulphate aluminium cement (SAC) substitution ratio. The slurry time-dependent shear stress, apparent viscosity and gas foaming property were measured to evaluate the rough-body stability during the coupling of foaming and thickening process. Physic-mechanical properties were carried out to evaluating the influence of binding materials on applicability. The mineral composition (XRD), thermal characteristics (TG-DSC) and crystal characteristics (29Si-NMR) of carbide slag based HUS-AAC hydration products were analyzed to making a thorough inquiry in the influence mechanism of binding materials on the mechanical properties. The results indicated that increasing OPC42.5 content can modify slurry properties in a small range, which was unable to meet the slurry adjustment target. Introducing of SAC can improve rough-body stability and shorten pre-curing time of HUS-AAC effectively. On the other hand, increasing proportion of OPC42.5 and SAC both has indistinctive effect on bulk density and positive effect on compressive strength of HUS-AAC. Furthermore, increment of OPC42.5 content resulted in increscent crystallinity and quantity of tobermorite, however, addition of SAC led to the opposite effect. The enhancement effect of SAC on HUS-AAC may attribute to the strengthen of pore partition material caused by substituting microcellular structure filling particles from soft white to tough quartz, which is equivalent to increase the strength of aggregate in pore partition material. In conclusion, from the angle of rough-body pre-curing stability and efficiency, and mechanical properties, the conventional OPC42.5 can be substituted by SAC completely.

The transition metal pentatelluride ZrTe5 has been studied extensively due to high thermoelectric power factors for potential applications in low-temperature refrigeration devices. Recent studies reveal that the physical properties of ZrTe5 are strongly dependent on Te concentration. Here, we have synthesized the Te-rich ZrTe5+δ polycrystalline by direct solid-state reaction and systematically investigated the electrical, magneto-transport and thermoelectric properties. Temperature-dependent resistivity and magneto-transport characterizations substantiate that ZrTe5+δ is a p-type (hole-doped) semiconductor. Besides, Seebeck coefficient is positive and linearly increases with T when T is within 10–150 K, and saturated to 120 μV K−1. Remarkably, a significant figure of merit ZT is obtained (∼0.037 at T = 300 K), which is higher than those in polycrystalline ZrTe5 (∼0.026) and sister compound HfTe5 (∼0.016) measured at 300 K. The significant thermoelectric performance of ZrTe5+δ is attributed to its low electrical resistivity (∼5 mΩ·cm), relative low thermal conductivity (∼2.0 W·K−1·m−1) and moderate Seebeck coefficient (∼120 μV K−1) at 300 K. Our work demonstrates the defect engineering, through delicate synthesis method, is an effective way to improve the thermoelectric property of ZrTe5.

Doping is a very effective method to promote the photocatalytic performance of graphitic carbon nitride (g-C3N4) based catalyst. However, the traditional co-condensation method causes the large particle size, small surface area and low separation rate of electrons-holes. In this work, halogen doped g-C3N4 nanorods with outstanding photocatalytic H2O2 production ability were prepared via saturated NH4X (X = Cl, Br) solution-hydrothermal post-treatment. XRD, N2 adsorption, UV–Vis, SEM, XPS, EPR, EIS and PL were used to characterize the obtained catalysts. Saturated salt solution-hydrothermal post-treatment changed the morphology and surface area of as-prepared g-C3N4 catalyst, as well as doped the halogen atoms into g-C3N4 lattice simultaneously. Br doped g-C3N4 catalyst displayed higher photocatalytic H2O2 production ability than that of Cl doped g-C3N4 catalyst. Compared with traditional co-condensation method, the catalyst prepared via saturated salt solution-hydrothermal post-treatment exhibited larger surface area, more effective separation rate and higher photocatalytic H2O2 production ability. This work can provide a new strategy for doping heteroatoms into g-C3N4 based catalyst.

PtRu alloy nanoparticles (NPs) in a commercial PtRu/C catalyst were encapsulated within few-layer graphitic boron nitride (h-BN) shells to form PtRu@h-BN/C core–shell catalysts, which were used as CO-tolerant anode catalyst in proton exchange membrane fuel cells (PEMFCs). Electrochemical results reveal that the PtRu@h-BN/C catalysts show similar activity in hydrogen oxidation reaction (HOR) as the PtRu/C catalysts but present enhanced CO-tolerance in fuel cell tests. Single cell performance with the PtRu@h-BN/C catalyst has been lowered by less than 20% with 30 ppm CO/25% CO2 introduced into H2 feed gas, while the PtRu/C catalyst suffers from a decrease of 60% under the same conditions. The reaction data and characterization results suggest that h-BN ultrathin shells can achieve a good balance between durability and activity, enabling the PtRu@h-BN/C material to act as a potential anode catalyst for PEMFCs.

Multi-walled carbon nanotubes supported nickel nanoparticles doped with magnesia and copper catalysts were prepared by incipient wetness impregnation method and used in adiponitrile (ADN) hydrogenation to 6-aminohexanenitrile (ACN) and 1,6-hexanediamine (HMDA). The prepared catalysts were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX), temperature-programmed hydrogen reduction (H2-TPR), H2 chemisorption, temperature-programmed ammonia desorption (NH3-TPD), temperature-programmed carbon dioxide desorption (CO2-TPD) and N2 adsorption-desorption. The results showed that the introduction of magnesia could lead to form NiO-MgO eutectic so as to restrain the reduction of nickel oxide, and it might increase the alkaline site which is conducive to the formation of primary amines in ADN hydrogenation so as to increase the selectivity to ACN and HMDA. Moreover, the formation of NiO-MgO eutectic can also inhibit the sintering of nickel in a certain extent, hence promote the nickel dispersion. And it was revealed that doping of copper can highly promote the catalytic activity by attributing to the strong synergetic effect between copper and nickel which can lead to better dispersion of nickel nanoparticles, larger metallic surface area, lower reduction activation energy of nickel oxide precursor and higher ratio of Ni0+ on the surface of the support. Multi-walled carbon nanotubes supported nickel nanoparticles doped with copper and magnesia presents the best catalytic performance of 96.27% conversion of ADN and 91.22% selectivity to ACN and HMDA under 2 MPa and lower temperature of 328 K.