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First principles studies are performed to discover the influences of different intercalated atoms and vacancies to the phosphorene/h-BN heterostructure. The metal impurities act as electron donors. On alkali metal intercalation the heterojunction was changed into metallic compounds, while 3 d transition- metals (TMs) offer shallow localized magnetic spin peaks contributing to electronic scattering. The most stable sites for four considered nonmetal atoms are different, and nonmetal layers are more stable than metal systems for their higher binding energies. The intrinsic vacancy defect boron monovacancy in h-BN sheet can magnetize the system, whereas the other vacancies and triangular vacancies act as nonmagnetic defects. It is revealed that atomic absorptions or vacancies can be well used to modulate electronic band structures of heterojunction over a wide range for high performance photovoltaic application, and to enhance the interlayer coupling concerning optimizing the electron scattering. [ABSTRACT FROM AUTHOR]

[Display omitted] • InN/VTe 2 vdW heterostructure presents room-temperature ferromagnetic semiconductor. • Band alignment and magnetic anisotropy energy can be tuned effectively by strain. • RT ferromagnetism remains unchanged under strain and electrostatic doping. • Significant enhancement of conductivity under electrostatic doping. • lnN/VTe 2 vdW heterostructure is a promising low-dimensional spintronic material. The room temperature ferromagnetism can be induced for nonmagnetic pristine graphene-like InN monolayer through establishing van der Waals heterostructure with ferromagnetic semiconductor, which could be applied for realizing novel low-dimensional spintronic devices. Here, we investigate the electronic structure and magnetic properties of InN/VTe 2 van der Waals heterostructure under strain and electrostatic doping by first-principles calculations. The InN/VTe 2 van der Waals heterostructure possesses desired physical properties such as a symmetric band alignment, ferromagnetic ground state, large in-plane magnetic anisotropy energy of 1.54 meV, and high Curie temperature of 354 K. Meanwhile, the band alignment and magnetic anisotropy energy for InN/VTe 2 van der Waals heterostructure can be also tuned effectively by strain. Significant enhancement of conductivity and robust above room temperature ferromagnetism exhibit in InN/VTe 2 van der Waals heterostructure under electrostatic doping and paves a new route toward a low-dimensional spintronic field-effect transistor. [ABSTRACT FROM AUTHOR]

Two PbS/ZnO nanocomposites with the same Pb/Zn molar ratio of 1:12 and different PbS/ZnO interface were prepared by depositing PbS nanocrystals on nano ZnO with the reaction between Pb(NO 3 ) 2 and Na 2 S through changing the sequence of adding Pb(NO 3 ) 2 and Na 2 S to the nano ZnO suspension: (A) first adding Pb(NO 3 ) 2 followed by adding Na 2 S (denoted PbS/ZnO-A); (B) first adding Na 2 S followed by adding Pb(NO 3 ) 2 (denoted PbS/ZnO-B). The PbS/ZnO nanocomposites are characterized by XRD, BET, Raman, TEM, XPS, and UV–vis–IR. The characterizations indicate that PbS/ZnO-A has an interface of PbS nanocrystal closely contacted to ZnO nanocrystal while PbS/ZnO-B has an interface of a disordered layer between PbS nanocrystal and ZnO nanocrystal. It is found for the first time that the PbS/ZnO interface plays an important role in their photodetection performance. PbS/ZnO-A exhibits much higher photoresponse current and lower rise and recovery time than both PbS/ZnO-B and a mixture of nano PbS and ZnO with the same Pb/Zn molar ratio as PbS/ZnO-A for visible and near-infrared photodetection. PL and the impedance measurement in dark and irradiation reveal that the superior photodetection performance of PbS/ZnO-A over PbS/ZnO-B is attributed to its lower e–h recombination and migration resistance under the irradiation of visible and infrared light due to its very good PbS/ZnO interface of PbS nanocrystals closely attached ZnO nanocrystals, through which photogenerated electrons inject efficiently from the conduction band of PbS to that of ZnO. In contrast, the defect sites in the disordered layer between PbS nanocrystal and ZnO nanocrystal for PbS/ZnO-B act as e–h recombination centers, significantly decreasing the e–h separation efficiency. [ABSTRACT FROM AUTHOR]

Abstract: Raw cotton fiber is water repellent due to the existence of the water repellent cuticle layer. This study is designed to systematically investigate how He/O2 atmospheric pressure plasma jet (APPJ) treatments influence the wettability and the sizing property of cotton yarns. Water absorption time and adhesion of the sizing agent to the cotton roving are used to evaluate the improvement of wettability and sizing property of the yarn respectively. The water absorption time decreases with the increase of the treatment time and the oxygen flow rate, and the decrease of the jet to substrate distance (JTSD). An optimal water absorption time of 0.8s is obtained with a treatment time of 20s, JTSD of 1mm and O2 flow rate of 0.2L/min. Scanning electron microscopy (SEM) shows that the etching effect increases with the decrease of the JTSD and X-ray photoelectron spectroscopy (XPS) presents increased oxygen contents after the plasma treatments. An increase of O–Chile a decrease of C–OH/C–O–C bonds are observed when the JTSD is set at 2mm. However, a remarkable increase of both C–OH/C–O–C and O–Cre achieved when the JTSD is 1mm. The roving impregnation test results show a nearly doubled adhesion of sizing and a slightly improved breaking elongation, indicating that the plasma treatment does effectively enhance the bonding strength between the fiber and the sizing. [Copyright &y& Elsevier]

Abstract: Polyamide 6 (PA 6) films are treated with helium(He)/CF4 plasma at atmospheric pressure. The samples are treated at different treatment times. The surface modification of the PA 6 films is evaluated by water contact angle, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The etching rate is used to study the etching effect of He/CF4 plasma on the PA 6 films. The T-peel strengths of the control and plasma treated films are measured to show the surface adhesion properties of the films. As the treatment time increases, the etching rate decreases steadily, the contact angle decreases initially and then increases, while the T-peel strength increases first and then decreases. AFM analyses show that the surface roughness increases after the plasma treatment. XPS analyses reveal substantial incorporation of fluorine and/or oxygen atoms to the polymer chains on the film surfaces. [Copyright &y& Elsevier]

[Display omitted] • For the first time, the effect of twisting on phonon transport of penta-sheet has been studied. • The in-plane lattice thermal conductivity of bilayer penta-graphene with a twist angle of 36.87° is reduced by 77.16% as compared to that of untwisted one. • The interlayer twisting not only can enhance three- and four-phonon scattering but also can uplift phonon coherence. Penta-graphene (PG) is the well-known prototype of the extensively studied 2D pentagon-based materials in recent years, and twisting strategy has been widely used to tune the properties of 2D sheets since the discovery of superconductivity in twisted bilayer graphene. However, no study is reported on how twisting affects the phonon properties of such penta-sheets. In this work, for the first time, we study the effect of twisting on the phonon transport properties of PG by using density functional theory and the phonon Boltzmann transport equation combined with two-channel transport theory and machine learning method. It is found that the in-plane lattice thermal conductivity of the twisted bilayer PG with a twist angle of 36.87° is only 96.72 W/mK at 300 K, reduced by 77.16% as compared to that of untwisted bilayer PG, and the four-phonon interaction further reduces the thermal conductivity by nearly 36%, while the coherence contribution to the thermal conductivity is enhanced to 9.69 W/mK from 0.13 W/mK by twisting. These results indicate that interlayer twisting not only can enhance three- and four-phonon scattering but also can uplift phonon coherence due to the resulted complex atomic configuration and high anharmonicity in bilayer PG. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fluorophlogopite mica can be used as an alkali metal source to assist in the growth of 2D materials. • Fluorophlogopite mica can act as alkali metal ions to assist in the growth of 2D materials at high temperatures. • The obtained 2D MoO 2 has a good conductivity. Everyone familiar with two-dimensional (2D) materials is aware of fluorophlogopite mica (FM), which has an atomic-level flat surface that provides an ideal platform for the growth of 2D materials. Since it has been demonstrated that the alkali metal ions (AMI) can aid in the growth of large-sized 2D materials by chemical vapor deposition (CVD) in recent years, it became a major mystery whether FM which contains AMI benefits from them in the preparation of 2D materials by CVD, too. In this article, we dispelled this ambiguity and discovered that temperature is the key for FM as an AMI source to boost the growth of large-sized 2D materials. We carried out variable temperature experiments and found that FM can indeed be incorporated into the growth of large-sized 2D materials as an AMI source at high temperatures and successfully obtained the highly crystalline MoO 2 with a larger size compared to those without FM. This finding is of great importance to the understanding of the growth mechanism of FM for 2D materials by CVD and to better exploit its role in the growth of 2D materials. [ABSTRACT FROM AUTHOR]

An easy and effective route to magnetic semiconducting ferrite oxynitrides with nitrogen doping tailored optical, magnetic, and electrical properties is developed by reactive magnetron sputtering. [Display omitted] • The nitrogen dopants in spinel ferrite (e.g., LiFe 5 O 8-x N y) epitaxial films have been systematically tailored by different deposition atmosphere. • Nitrogen doping can significantly enhance the light absorption and electrical performance for lithium ferrite films. • The nitrogen doping effect on the electronic structures and resultant properties of lithium ferrite has been elucidated by combined experimental and theoretical studies. The powerful means of nitrogen doping has been applied to perovskite, rocksalt, anatase, and fluorite oxides to tailor crystal structures, electronic/chemical states, and resultant physical/chemical properties for electronic/optical/magnetic device, catalysis, and energy conversion. However, it is rare for nitrogen-doped spinel oxides, especially for spinel ferrites. Here, we take spinel lithium ferrite (LiFe 5 O 8) as an archetype to elucidate the nitrogen doping effect on the optical, magnetic, and electrical properties. The nitrogen dopants in lithium ferrite oxynitride (LiFe 5 O 8-x N y) epitaxial films have been systematically manipulated by adjusting the deposition atmospheres during sputtering growth. Remarkably, nitrogen doping leads to a significant enhancement in both light absorption (approximately twice as enhanced at 2.1 eV) and electrical performance (up to 6 order enhancement) for lithium ferrites. The combined experimental and theoretical studies reveal that the nitrogen doping effect can effectively narrow the bandgap and create in-gap states that give rise to enhanced light absorption and electrical performance. Our study sheds light on a profound understanding of nitrogen doping-tailored crystal and electronic structures of spinel ferrites and provides a novel, easy, and effective route to magnetic semiconducting ferrite oxynitrides with boosted light absorption and electrical performance, which can be beneficial to spintronic and photochemistry applications. [ABSTRACT FROM AUTHOR]

Abstract: This paper studies the influence of moisture absorption of cotton fabrics on the effectiveness of atmospheric pressure plasma jet (APPJ) on desizing of polyvinyl alcohol (PVA). Cotton fabrics with three different moisture regains (MR), namely 1.8%, 7.3%, and 28.4% corresponding to 10%, 65%, and 98% of relative humidity respectively, are treated for 16s, 32s, 48s, and 64s. X-ray photoelectron spectroscopy analysis indicates that the plasma treated PVA has higher oxygen concentration than the control. Mass loss results show that the fabric with the highest MR has the largest mass loss after 64s plasma exposure. Solubility measurement reveals that the sample with the lowest MR has the highest desizing efficacy and the percent desizing ratio reaches 96% after 64s exposure plus a 20min hot wash, which is shown as clean as the unsized sample through scanning electron microscopy analysis. The yarn tensile strength test results show that APPJ has no negative effect on fabric tensile strength. [Copyright &y& Elsevier]

Abstract: The effect of argon/oxygen atmospheric dielectric barrier discharge (DBD) treatment on desizing and scouring of polyvinyl alcohol (PVA) on cotton fabric was studied with respect to the treatment duration of 1, 2, 4 and 6min. X-ray photoelectron spectroscopy (XPS) analysis indicated that oxygen concentration increased for the plasma treated PVA film. Solubility measurement revealed that plasma treatment increased PVA solubility in hot washing but less effective in cold washing. Scanning electron microscopy (SEM) showed that the fiber surfaces were as clean as unsized fibers after 6min treatment followed by hot washing. Wickability analysis indicated that the capillary heights of plasma treated fabrics increased significantly as the plasma treatment duration increased. The results of the yarn tensile strength test showed that the plasma treatment did not have a negative effect on fabric tensile strength. [Copyright &y& Elsevier]

Abstract: This study is designed to systematically investigate how various factors, such as treatment duration, output power, oxygen gas flux, jet to substrate distance, and moisture regain, influence atmospheric pressure plasma etching rate of polyamide 6 (PA 6) films. The etching rate increased as the output power, oxygen gas flux, and moisture regain increased. As the treatment time increased, the etching rate increased first and then decreased. When the substrate was too close or too far from the nozzle, the etching rate was almost not measurable. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) show an increased surface roughness after the plasma treatment. X-ray photoelectron spectroscopy (XPS) shows a decreased carbon content and an increased oxygen content after the plasma treatment. T-peel strength shows an improved bonding strength between the PA 6 films and an adhesive tape after the plasma treatment. [Copyright &y& Elsevier]

Abstract Developing of novel chemiresistive gas sensing materials with desired unique gas chemisorption properties is of great important. In this work, motivated by the special electronic structure, Ag 3 PO 4 semiconductor is systematically investigated as gas sensing material for the first time. Encouragingly, the Ag 3 PO 4 nanoparticles based gas sensors exhibit high selectivity to NH 3 at near room temperature of 50 °C with negligible responses to the other gases (including H 2 , CO, ethanol, acetone, NO 2 and SO 2). Furthermore, the responses decreased with the increase of operating temperature from 50 to 100 °C, indicating the superior NH 3 sensing activity. The in-situ infrared characterization and theoretical calculations reveal that the lone pair of NH 3 coordinate with the superficial silver atoms of Ag 3 PO 4 accompanied with strong adsorption energy, efficient quantities electron migration and thermodynamic favorable, explained the origin of the high selectivity. Our work indicates that Ag 3 PO 4 based materials are very promising low operating temperature and highly selective NH 3 -sensing materials. Graphical abstract Unlabelled Image Highlights • Ag 3 PO 4 semiconductor is systematically investigated for the first time as chemiresistive gas sensing material. • Ag 3 PO 4 based gas sensors exhibit highly selectivity to NH 3 at 50 oC with negligible responses to other gases. • The highly selectivity of Ag 3 PO 4 is originated from the coordination between the lone pair of NH 3 and silver atoms. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Hierarchical micro- and mesoporous carbon material is fabricated for supercapacitor. • Hydrothermal treatment process strongly affects the pore size distribution of the prepared carbon material. • Specific capacitances of 389 F g−1 at 0.2 A g−1 and 202 F g−1 at 10 A g−1 were achieved. • 91.6% of the initial capacitance was retained after 10,000 cycles at 10–50 A g−1. Abstract Biomass-derived carbons with hierarchical porous structures are widely considered as one of the most promising electrodes for supercapacitor. In this work, we present a facile approach to synthesize hierarchical porous carbon materials from waste lentinus edodes. It exhibits that the duration of the hydrothermal treatment process strongly affects the pore size distribution of the prepared carbon materials. Many narrow pores are formed during the hydrothermal process; these preformed pores are vital for the formation of micropores and development of larger mesopores in the following molten salt activation process. The as-obtained HM-24, synthesized by hydrothermally treated for 24 h and subsequently activated in molten Na 2 CO 3 -K 2 CO 3 for 1 h, possesses high specific surface area of 1144 m2 g−1 and developed hierarchical micro- and mesoporous structures. Moreover, oxygen- and nitrogen-containing functional groups are detected at the carbon surface. When evaluated as an electrode in a three-electrode system with 1 M H 2 SO 4 electrolyte, the as-prepared HM-24 exhibits a high specific capacitance of 389 F g−1 at 0.2 A g−1 and a good rate capacity with capacitance remaining 174 F g−1 at 20 A g−1. Furthermore, the assembled symmetric supercapacitor delivers a high specific capacitance of 329 F g−1 at 0.2 A g−1, excellent energy density of 45.69 Wh kg−1 and good cycling stability which retains 90.3% of the initial capacitance at 5 A g−1 after 10,000 cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ti 4 O 7 /Mxene composite electrocatalysts have been synthesized with simple method. • Ti 4 O 7 and Mxene can complement the shortcomings and improve the catalytic activity. • The synthesized catalysts exhibit excellent ORR catalytic performance and stability. Electrocatalysts play an important role in the cathodic Oxygen Reduction Reaction (ORR) of fuel cells. Because of the high cost, poor cycle stability and methanol tolerance, the commercial Pt/C catalysts have been seriously restricted during large-scale application and development in electrochemical devices. The development of non-noble metal ORR catalysts is one of the effective ways to achieve fuel cell cost reduction and performance improvement at the same time. In this work, Ti 4 O 7 /MXene nanocomposites were synthesized through hydrothermal followed by carbothermal reduction reactions. Such catalysts exhibit large electrochemical active surface area (ECSA = 215.74 cm2) and excellent ORR catalytic activity in alkaline media. The initial potential and half-wave potential were confirmed to be 0.91 V and 0.72 V with the electron transfer number of 3.3. In addition, the Ti 4 O 7 /MXene catalysts have better cyclic stability and methanol tolerance than commercial Pt/C catalyst. This study provides a new idea and method for the innovative preparation of MXene-based composite electrocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • CF@MnO 2 composites with controllable structure were prepared by a facile hydrothermal method. • The growth process of MnO 2 was studied. • The effect of micro morphology on electromagnetic wave absorption performance was studied. Recently, electromagnetic wave (EMW) absorption materials with enhanced and tunable EMW absorption performance are required in practical applications, and attaining such performance by a simple method remains a vital challenge. In this study, manganese dioxide (MnO 2) with controllable structures were vertically grown on carbon fibers (CF) through a hydrothermal method. The sheet-like (CF@MnO 2 -NS) and wire-like (CF@MnO 2 -NW) structures were obtained by merely adjusting the solution chemistries ([K+] and [H+]) and reaction time. The wire-like structure exhibited high attenuation capability due to a larger specific surface area and dielectric resonance, but exhibited a relatively poor impedance matching ratio resulting in inferior EMW absorption performance at low frequencies. However, the sheet-like structure exhibited better EMW absorption performance overall. The minimum reflection loss (RL min) value of CF@MnO 2 -NS and CF@MnO 2 -NW reached −56.6 dB and −52.9 dB, respectively. Additionally, the EMW absorption performance varies with frequency. CF@MnO 2 -NW performed better in the X-band, while CF@MnO 2 -NS achieved an excellent performance in the C-band. This study provides a simple approach for designing EMW absorption materials with controllable morphologies and for realizing tunable EMW performances. [ABSTRACT FROM AUTHOR]

[Display omitted] • PPy-SFB was prepared by in-situ polymerization of pyrrole in presence of waste rice straw. • PPy-SFB showed preferable Cr(VI) adsorption both in static and dynamic adsorption. • The adsorption was monolayer chemisorption, endothermic and spontaneous in nature. • Most of the adsorbed Cr(VI) on PPy-SFB was reduced in situ to the less toxic Cr(III). • Cr resource was recycled as pure Cr 2 O 3 by calcining the Cr(VI) adsorbed PPy-SFB. Rice straw fiber ball coated with polypyrrole (PPy-SFB), a novel adsorbent, was prepared from waste rice straw through in-situ oxidative polymerization of pyrrole monomer. The Cr(VI) adsorption characteristics of PPy-SFB were investigated not only in batch experiments but also in the column experiments, the isothermal models (Langmuir, Freundlich and Temkin), the kinetic models (Pseudo-first-order kinetic, Pseudo-second-order kinetic and Intra-particle diffusion models), and the dynamic models (Adams-Bohart, Thomas and Yoon-Nelson) were used to describe the adsorption behavior. The Cr(VI) removal mechanism of PPy-SFB was revealed by studying the effect of pH on adsorption, testing of Cl−, and analyzing the XPS. The results showed that PPy-SFB could efficiently adsorb and reduce Cr(VI) from water, and the maximum adsorption capacity reached 122.15 mg g−1 at 30 ℃ and pH = 3.0. Adsorption of Cr(VI) by PPy-SFB followed the Langmuir isotherm model, Pseudo-second-order kinetic model and Yoon-Nelson model. The thermodynamic parameters (ΔG0 < 0, ΔH0 > 0 and ΔS0 > 0) indicated that the adsorption process was endothermic and spontaneous in nature. The electrostatic interaction, ion exchange between Cl− and Cr(VI), and reduction of the PPy-SFB surface were attributed to the high efficient removal of Cr(VI). In addition, the adsorbed Cr(VI) was recovered in the form of pure Cr 2 O 3 by simple incineration. [ABSTRACT FROM AUTHOR]

Abstract: Two-dimensional ordered patterns of n-tetradecane (n-C14H30) and n-hexadecane (n-C16H34) molecules at liquid/graphite interface have been directly imaged using scanning tunneling microscope (STM) under ambient conditions. STM images reveal that the two different kinds of molecules self-organize into ordered lamellar structures in which alkane chains of the molecules extend along one of three equivalent lattice axes of highly oriented pyrolytic graphite (HOPG) basal plane. For n-C14H30 molecules, the molecular axes are observed to tilt by 60° with respect to inter-lamellar trough lines and the carbon backbones of the alkane chains are perpendicular to the HOPG basal plane in an all-trans conformation. However, for n-C16H34 molecules, the molecular axes are perpendicular to lamellar borders (90°) and the planes of the all-trans carbon skeletons are parallel to the graphite basal plane. The results clearly indicate that outmost hydrogen atoms of the alkane chains dominate atom-scaled features of the STM images. That is, in the case of long-chain alkane molecules, topographic effects dominantly determine STM image contrast of the methylene regions of the alkane chains that are adsorbed on HOPG. [ABSTRACT FROM AUTHOR]

Abstract: ZnO thin films with highly c-axis orientation have been fabricated on p-type Si(111) substrates at 400°C by pulsed laser deposition (PLD) from a metallic Zn target with oxygen pressures between 0.1 and 0.7mbar. Experimental results indicate that the films deposited at 0.3 and 0.5mbar have better crystalline and optical quality and flatter surfaces than the films prepared at other pressures. The full width at half maximum (FWHM) of (0002) diffraction peak decreases remarkably from 0.46 to 0.19° with increasing annealing temperature for the film prepared at 0.3mbar. In photoluminescence (PL) spectra at room temperature, the annealed film at 700°C exhibits a smaller ultraviolet (UV) peak FWHM of 108meV than the as-grown film (119meV). However, an enhanced deep-level emission is observed. Possible origins to above results are discussed. [Copyright &y& Elsevier]