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Abstract As a superior p-type wide bandgap semiconductor, β-CuSCN has a huge potential in optoelectronic device application, and however its conduction could intensively be affected by externally applied bias. Here, we demonstrate electrodeposited individual β-CuSCN trigonal micro/nanopyramids and their array films can show Cu+ trap-controlled bias dependence of electron transport. Before being subjected to a large reverse bias or a unidirectional bias, their cyclic I V curves are coincident resulted from bulk-trap related carrier hopping. At relatively large bidirectional operation bias, they can symmetrically present two large hysteresis loops with negative differential resistance (NDR), and meanwhile accompany with nonvolatile negative resistive switching (RS) feature. After being applied respectively a relatively large fixed bias in two opposite directions, more importantly, switchable classic asymmetrical bipolar RS can successfully be realized at a relatively low operation bias. The switchable formation of reversion and depletion layer, resulted from the minority carriers (electrons) injection into the traps of surface connected with negative electrode, plays a crucial role. Under relatively large bias, the synergistic effect of two surface trap-related back-to-back connected bipolar RS devices results in symmetrical negative RS with NDR. After being applied a relatively large fixed bias, the bipolar RS effect can be enhanced at the surface connected with negative electrode due to the presence of electron injection induced high and narrow barrier, and conversely it disappears at the surface connected with positive electrode due to hole injection-induced ohmic contact. Then, the devices can be set and reset by the filling and emptying of holes in the thin reversion and depletion layer at low reverse and forward voltages, respectively, showing switchable bipolar RS behavior. Due to superior stability, reversibility, nondestructive readout, and low operation bias as well as remarkable cycle performance, the bias-governed conduction with negative RS and switchable bipolar RS makes it a potential candidate in next-generation erasable nonvolatile RRAM devices. Graphical abstract Individual β-CuSCN trigonal micro/nanopyramids and their array films can show Cu+ trap-controlled bias dependence of conduction. Before, under and after applying a large bias, they can show the behaviour of bulk-trap related carrier hopping, symmetrical nonvolatile negative RS characteristics with NDR, and switchable bipolar RS, respectively. The switchable formation of electron injection-induced reversion and depletion layer plays a crucial role at the surface connected with negative electrode. Unlabelled Image Highlights • Individual β-CuSCN micro/nanopyramids and their array films can show bias dependence of electron transport characteristics. • Before being subjected to a large reverse bias or at a unidirectional bias, their cyclic I-V curves are coincident. • Two symmetrical hysteresis loops with negative differential resistance only appear at large bidirectional operation bias. • Switchable bipolar resistive switching is realized after applying large fixed bias in two opposite directions, respectively. • Negative resistive switching can controllably be set and reset by large reverse and forward bias voltage, respectively. [ABSTRACT FROM AUTHOR]

Perovskite oxide SrTiO 3 is a promising semiconductor photocatalyst for CO 2 reduction, which has two possible chemical surfaces—TiO 2 -terminated and SrO-terminated surfaces. Up to now, the effect of chemical surface and its modification on CO 2 adsorption, activation and sequential photocatalytic reduction is not established. In the work, SrTiO 3 , surface-Ti-rich SrTiO 3 and Sr(OH) 2 -decorated SrTiO 3 were prepared and their structural, surface, and optical properties and photocatalytic activity were explored. It is found that the absorption edge of surface-Ti-rich SrTiO 3 shifted toward visible-light region as compared with that of the other two photocatalysts, which is attributed to the decreased Ti 3d ground-state level at the surface. Bicarbonate- (HCO 3 − ) and bidentate carbonate-like (b-CO 3 = ) species are the main species for CO 2 adsorption on the surface-Ti-rich SrTiO 3 , whereas, besides HCO 3 − and b-CO 3 = , plenty of monodentate carbonate-like species (m-CO 3 = ) that has relatively low reactivity is present on the SrTiO 3 and Sr(OH) 2 -decorated photocatalysts. As a result, the surface-Ti-rich SrTiO 3 exhibits the highest activity for CO 2 reduction. Furthermore, although Sr(OH) 2 -decoration and SrO-terminated surfaces facilitate CO 2 fixing, the produced surface species are attached to the weakly active Sr ions, giving rise to the lower reactivity. The present work might supply a guide for designing highly active perovskite–type semiconductors for photocatalysis. [ABSTRACT FROM AUTHOR]

Abstract: This work described the graft polymerization of a sulfonic acid terminated monomer, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), onto the surface of polypropylene non-woven (NWF PP) membrane by O2 plasma pretreatment and UV-induced photografting method. The chemical structure and composition of the modified surfaces were analyzed by FTIR-ATR and XPS, respectively. The wettability was investigated by water contact angle and equilibrium water adsorption. And the biocompatibility of the modified NWF PP membranes was evaluated by protein adsorption and platelet adhesion. It was found that the graft density increased with prolonging UV irradiation time and increasing AMPS concentration; the water contact angles of the membranes decreased from 124° to 26° with the increasing grafting density of poly(AMPS) from 0 to 884.2μgcm−2, while the equilibrium water adsorption raised from 5wt% to 75wt%; the protein absorption was effectively suppressed with the introduction of poly(AMPS) even at the low grafting density (132.4μgcm−2); the number of platelets adhering to the modified membrane was dramatically reduced when compared with that on its virgin surface. These results indicated that surface modification of NWF PP membrane with AMPS was a facile approach to construct biocompatible surface. [Copyright &y& Elsevier]

Abstract: CdSe thin films have been grown on GaAs (001) substrates by molecular beam epitaxy (MBE). The effects of substrate temperature and annealing treatment on the structural properties of CdSe layers were investigated. The growth rate slightly decreases due to the accelerated desorption of Cd from CdSe surface with an increase in the temperature. The sample grown at 260°C shows a polycrystalline structure with rough surface. As the temperature increases over 300°C, crystalline CdSe (001) epilayers with zinc-blende structure are achieved and the structural quality is improved remarkably. The epilayer grown at 340°C displays the narrowest full-width at half-maximum (FWHM) from (004) reflection in double-crystal X-ray rocking curve (DCXRC) and the smallest root-mean-square (RMS) roughness of 0.816nm. Additionally, samples fabricated at 320°C were annealed in air for 30min to study the films’ thermal stability. X-ray diffraction (XRD) results indicate that the zinc-blende structure remains unchanged when the annealing temperature is elevated to 460°C, meaning a good thermal stability of the cubic CdSe epilayers. [Copyright &y& Elsevier]

Abstract: Polypropylene (PP) was modified with 2-hydroxyethyl acrylate (HEA) by solution radical grafting to introduce active hydroxyl groups on polypropylene backbone (PP-g-HEA). Then the biomimic monomer, 2-methacryloyloxyethyl phosphorycholine (MPC), was grafted onto the surface of PP-g-HEA film (PP-g-HEA-g-MPC) by redox graft polymerizations with ceric(IV) ammonium nitrate as an initiator. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) showed that the HEA and MPC were introduced onto PP molecular chains and the copolymer, PP-g-HEA-g-MPC were formed. The water contact angle measurements demonstrated that the final modified PP film exhibited a better hydrophilic surface compared to the neat PP film. The platelets adhesion on the neat PP, PP-g-HEA and PP-g-HEA-g-MPC film was examined by scanning electron microscopy (SEM). It was found that a large number of platelets were adhered and activated on the surface of neat PP and PP-g-HEA films, while the number of platelets on PP-g-HEA-g-MPC surface was decreased remarkably. The result revealed that the introduction of poly(MPC) onto the PP surface improved the hemocompatibility of PP substantially. [Copyright &y& Elsevier]

Abstract: ZnTe epilayers were grown on GaAs(001) substrates by molecular beam epitaxy (MBE) at different VI/II beam equivalent pressure (BEP) ratios (R VI/II) in a wide range of 0.96–11 with constant Zn flux. Based on in situ reflection high-energy electron diffraction (RHEED) observation, two-dimensional (2D) growth mode can be formed by increasing the R VI/II to 2.8. The Te/Zn pressure ratios lower than 4.0 correspond to Zn-rich growth state, while the ratios over 6.4 correspond to Te-rich one. The Zn sticking coefficient at various VI/II ratios are derived by the growth rate measurement. The ZnTe epilayer grown at a R VI/II of 6.4 displays the narrowest full-width at half-maximum (FWHM) of double-crystal X-ray rocking curve (DCXRC) for (004) reflection. Atomic force microscopy (AFM) characterization shows that the grain size enlarges drastically with the R VI/II. The surface root-mean-square (RMS) roughness decreases firstly, attains a minimum of 1.14nm at a R VI/II of 4.0 and then increases at higher ratios. It is suggested that the most suitable R VI/II be controlled between 4.0 and 6.4 in order to grow high-quality ZnTe epitaxial thin films. [Copyright &y& Elsevier]

Abstract: Epitaxial ZnO thin films have been synthesized directly on Si(111) substrates by pulsed laser deposition (PLD) in vacuum. The reflection high-energy electron diffraction (RHEED) indicates that streaky patterns can be clearly observed from the ZnO epilayers prepared at 600 and 650°C, revealing a two-dimensional (2D) growth mode. While the ZnO thin film deposited in oxygen ambient shows ring RHEED pattern. There is a compressive in-plane stress existing in the ZnO epitaxial film, but a tensile one in the polycrystalline film. Compared with the ZnO epilayer, the ZnO polycrystalline film shows more intense ultraviolet emission (UVE) with a small full width at half maximum (FWHM) of 89meV. It is suggested that the atomically flat epilayers may be powerfully used as transitive stratums to grow high-quality ZnO films suitable for the fabrication of optoelectronic devices. [Copyright &y& Elsevier]

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]

ZnO thin films were fabricated on Si (1 1 1) substrates by oxidation of metallic Zn films in air. A thin layer of Au was used to enhance the adhesion of the Zn atoms to the Si surface during depositing the Zn films on the substrates at room temperature (RT) by thermal evaporation. X-ray diffraction (XRD) studies indicate that the ZnO film prepared at 500 °C has better crystalline quality than films prepared at other temperatures. In photoluminescence (PL) spectra at room temperature, the film oxidized at 500 °C exhibits the biggest intensity ratio of 162 of ultraviolet (UV) emission to deep-level emission and the narrowest UV peak full width at half maximum (FWHM) of 94.8 meV. These results reveal that high-quality ZnO thin films with good crystallinity and strong UV emission can be achieved at such low temperature. It was also observed that the deep-level emission would become dominant in the PL spectra for the samples annealed at high temperatures above 700 °C, and the possible origin was discussed. [Copyright &y& Elsevier]

α-Fe 2 O 3 /BiOCl heterojunctions were synthesized by growing and assembling α-Fe 2 O 3 nanoplates to BiOCl microflowers via a two-step route to enhance the photocatalytic performance of BiOCl. The morphology, microstructure, element composition and optical properties of α-Fe 2 O 3 /BiOCl heterojunctions have been investigated by SEM, TEM, XRD, FT-IR, Raman spectra, XPS, UV–vis diffuse reflectance and PL spectra. Electrostatic interaction was a key to form α-Fe 2 O 3 /BiOCl heterojunctions. Compared with pure BiOCl, the synthesized α-Fe 2 O 3 /BiOCl heterojunctions possess an efficient visible light absorption and exhibit an improved of photocatalytic efficiency. A photocatalytic degradation mechanism has been proposed to explain that the heterojunctions enhance the separation efficiency of electron-hole pairs, and the holes are the main reactive species in the degratation of Rhodamine B. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman scattering (SERS) substrate of Ti(OH) 4 nanobelt arrays (NBAs) was synthesized by a hydrothermal reaction, on which silver nanoparticles (NPs) were deposited by pulsed laser deposition (PLD). Field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) revealed the effective high specific surface area with silver NPs decorated on three-dimensional NBAs. Using rhodamine 6G (R6G) as an analyte molecule, the highest enhancement factor of 10 6 and a maximum relative standard deviation (RSD) of 0.18 were obtained. It has been found that the specific morphology of these composite nanobelt arrays and the formation of Ag 2 O play important role for the high sensitivity Raman phenomenon. In addition, the surface plasmon resonance wavelength of Ag decorated Ti(OH) 4 NBAs and the charge transfer from Ag NPs are also responsible for the enhancement ability. For comparison SERS was investigated with silver particles decorated on TiO 2 NBAs, which is much less active. [ABSTRACT FROM AUTHOR]

The oxidation behavior of a single-crystal Ni-based superalloy over the temperature range of 850 °C–950 °C and under R a = 0.1–0.2 μm was investigated. The oxidation kinetics of the superalloy presented two stages. The first and second stages had activation energies of 222 and 263 KJ·mol−1, respectively. The oxide film comprised NiO, NiCr 2 O 4 , CrTaO 4 , and Al 2 O 3. The formation time of the continuous Al 2 O 3 layer corresponded to the transition point of oxidation kinetics at each temperature. Mass gain in the first stage could be attributed to the formation of an outer NiO layer and an inner alumina layer, whereas that in the second stage could be ascribed to the growth of intermediate spinel layers. • NiO was the first species formed on the surface under the R a = 0.1–0.2 μm of this alloy. • Two oxidation stages were observed at each temperature. • The evolution of outer NiO, inner Al 2 O 3 and intermediate spinels played a different role on the oxidation kinetics. • The morphology of inner Al 2 O 3 layer was responsible for the transition of oxidation kinetics. [ABSTRACT FROM AUTHOR]

The thrombus formation and oxidation of blood components caused by blood-contacting biomaterials were main reasons for poor hemocompatibility of biomaterials. To construct the anti-thrombotic and anti-oxidative surface, we electrospun styrene-b-(ethylene-co-butylene)-b-styrene elastomer (SEBS)/acylated Pluronic F127 (A-F127)/L-ascorbic acid (AA) microfibers based on the SEBS substrate in one step. Our strategy was based on that the phase-separation between SEBS and A-F127 during electrospinning resulted in hydrophilic surface of microfibers, the crosslinking of electrospun meshes rendered the surface stable, and the AA release from the microfibers interacted with blood cells actively to prevent blood cells from oxidative damage. We demonstrated that the self-assembly of SEBS/A-F127 blends resulted in the similar structure as core-shell microfibers with the A-F127 richness in the sheath; the presence of A-F127 on the out layer made the microfibers hydrophilic and rendered the microfibers anti-thrombotic; the release of AA from the microfibers in the PBS solution was temperature-dependent; AA acted as the antioxidant to decrease the oxidative damage of blood cells after long-term contact between biomaterials and blood. Our work paves a new way to develop long-term hemocompatible biomaterials, which may be helpful to prevent blood cells from oxidative damage to maintain the normal function of blood cells in vivo . [ABSTRACT FROM AUTHOR]

A mild and low-cost strategy for fabricating nanoporous silver (NPS) thin films loaded on Ni wire were reported via co-electrodeposition of Ag-Sn alloy and subsequent dealloying in alkaline solution. Scanning electron microscope (SEM) and energy dispersive spectrum (EDS) were performed to investigate the morphology and composition of the electrodes. The crystal structures of the precursor alloy and NPS were examined by X-ray diffraction (XRD). After selectively etching the Sn out of the Ag-Sn alloy, an unordered three-dimensional bicontinuous nanoporous structure was observed, with a pore size of ∼50–120 nm and a ligament size of ∼40–200 nm. The NPS electrodes presented linear current response to hydrogen peroxide under the concentration ranging from 0.010 to 8.000 mM, with an excellent correlation coefficient (R 2 ) of 0.99998. The high sensitivity, reliability, anti-interference ability, stability and short response time indicate its potential in real-time monitoring H 2 O 2 . [ABSTRACT FROM AUTHOR]

The SrBi 2 Nb 2 O 9 platelets with a thickness of about 600 nm were synthesized by molten salt synthesis method. The treatment of the SrBi 2 Nb 2 O 9 platelets with hydrochloric acid resulted in the formation of the protonated H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 platelets. Through a top–down approach in ethylamine solution, the H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 platelets were exfoliated into H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 nanosheets with a thickness of about 2.6 nm. The evolution of the structure, composition, morphology, optical, and photocatalytic properties of SrBi 2 Nb 2 O 9 platelets was studied as it is converted into H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 platelets and subsequently exfoliated into H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 nanosheets. The absorption edge shifts to a lower wavelength accompanied by the protonation and exfoliation. The photocatalytic H 2 evolution of the three samples were evaluated under the irradiation of a 300 W Xenon lamp from CH 3 OH/H 2 O solution, indicating that H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 nanosheets Exhibit 5.5 and 26.2 times higher activity than that of the H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 and SrBi 2 Nb 2 O 9 platelets, respectively. The enhanced activity for the H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 nanosheets is mainly attributed to the higher separation efficiency of the photogenerated carriers and the larger specific surface area caused by the significant reduction in thickness. [ABSTRACT FROM AUTHOR]

For CNT/N-Co@TiO 2 nanohybrids, integrated with 0D embedded Co and coated TiO 2 nanoparticles, 1D CNTs, 2D carbon nanolayers, 3D spherical networks, and doped N and Co heteroatoms, the multifunction synergism of improved adsorption, effective expansion buffering, excellent conductivity and efficient catalysis can enhance significantly rate capacity and cycle performance. [Display omitted] • CNT/N-Co@TiO 2 nanohybrid integrated with multi-dimension nanostructures is synthesized. • 3D CNT/N provide huge space for PS accommodation and high channel for electron and Li+ ion transfer. • 0D polar TiO 2 nanoparticles provide affluent bonding sites, enhancing the adsorption ability to PS. • 0D Co and TiO 2 nanoparticles provide electrocatalytic centers, enhancing reutilization of PS. • Synergism of adsorption, expansion, conductivity and catalysis enhance Li-S battery performance. Lithium-sulfur (Li-S) battery is considered as one of the most prospective energy storage devices; nevertheless, its application is seriously impeded owing to lithium polysulfide (LPS) shuttle, volume expansion, poor conductivity of sulfur, and weak redox kinetics between various LPSs. Herein, multiple-structure nanohybrids (CNT/N-Co@TiO 2), integrated with zero-dimensional (0D) embedded-Co and coated-TiO 2 nanoparticles, 1D carbon nanotubes, quasi-2D carbon nanolayer, 3D spherical networks, and N, Co-codoped heteroatoms, are synthesized. The multifunction synergism of improved adsorption, effective expansion buffering, excellent conductivity and efficient catalysis observably strengthens battery performance with CNT/N-Co@TiO 2 -modified separator. An initial discharge capacity of 1320 mAh g−1 can achieve at 0.2C, and meanwhile an initial discharge capacity of 1051 mAh g−1 can acquire with 0.071% capacity decay rate per cycle over 500 cycles at 1C. An initial specific discharge capacity of 653 mAh g−1 can show at 3C. Impressively, even at 5.1 mg cm−1 high sulfur loading, a distinguished cycling stability of 640 mAh g−1 can maintain after 60 cycles at 0.1C. This work demonstrates that high efficiency Li-S batteries can be implemented via a multifunction synergism of multiple-structure nanohybrids integrated with high conductivity carbon, polar metal oxide, and high catalytic activity embedded and coated nanoparticles and doped heteroatoms. [ABSTRACT FROM AUTHOR]

A compact layer (blocking layer) can effectively block the direct contact between the fluorine-doped tin oxide (FTO) glass substrate and electrolyte in dye-sensitized solar cells (DSSCs). The TiCl 4 hydrolysis has been widely adopted for preparing the TiO 2 compact layer (H-TiO 2 ). However, the TiCl 4 aqueous solution is unstable for its high reactivity. To improve the chemical stability of TiCl 4 aqueous solution, the Ti 4+ is encapsulated by the polymer, polyethyleneimine (PEI). Experimentals show that the Ti-PEI precursor solution can maintain their initial performances for several months. The resulting TiO 2 film (P-TiO 2 ) grown by the Ti-PEI precursor is dense, smooth and uniform without any visible and detectable cracks or voids. The P-TiO 2 compact layer is even denser than the H-TiO 2 compact layer, suggesting reducing the electron recombination and prolonging the electron lifetime in dye-sensitized solar cells. Indeed, the electron lifetime of the DSSC based on the P-TiO 2 is 13.15 ms, which is longer than the 10.83 ms based on H-TiO 2 . Meanwhile, the power conversion efficiency of the DSSC based on P-TiO 2 compact film is about 12.5% higher than that based on H-TiO 2 . Therefore, this encapsulation technology can not only improve the stability of the metal ions solution but also meet a large-scale fabrication demand of the TiO 2 compact layer in future DSSCs. [ABSTRACT FROM AUTHOR]

The interaction of clay minerals and dyes is an area of great interest especially in the development of novel adsorbents. In this report, we demonstrated interaction of halloysite nanotubes (HNTs) and an anionic dye, methyl orange (MO), through a electrostatic attraction. Halloysite lumen has a trapping characteristic for methyl orange, which is mainly determined by the positively charged nature of the inner surface of HNTs. XRD results confirmed that intercalation of methyl orange into HNTs did not occur. SEM–EDS and photostability results showed that MO molecules were primarily in HNTs lumen. Adsorption isotherm studies revealed an interesting phenomenon, i.e., a sudden increase of adsorption capacity occurred in the initial dye concentration of about 75 mg/L, which was just the dye concentration corresponding to the onset of dye oligomer formation. This suggested dye aggregation state had a decisive influence to the adsorption behavior of MO on the halloysite. BET results demonstrated at low and high dye concentrations, single MO molecule and aggregation of several dimers through hydrophobic interaction, interacted with Al-OH 2 + sites on the inner wall, respectively. Desorption experiments showed that MO in HNTs can be completely removed with deionized water, indicating halloysite is a low-cost and efficient adsorbent for anionic dye. [ABSTRACT FROM AUTHOR]

[Display omitted] • The metal ions doped Bi 2 O 3 nanofibres with a novel morphology are prepared. • The photocatalytic performance of Bi 2 O 3 were enhanced through doping strategy. • Co2+ doped Bi 2 O 3 exhibits great photocatalytic activity on moxifloxacin degradation. • The main active species are h+ and the three degradation pathways are proposed. Photocatalytic degradation technology is a potential way to remove organic pollutants from water. In this study, Bi 2 O 3 nanofibres doped with different metal ions (Co2+, Ni2+, and Zn2+) were fabricated successfully using the electrospinning method for use as photocatalysts. Compared to pure Bi 2 O 3 nanofibres, the energy band gap and the recombination rate of photogenerated carriers were reduced in Co2+-doped Bi 2 O 3 nanofibers, which significantly improved the photocatalytic performance of the Bi 2 O 3 nanofibres. Typically, the moxifloxacin degradation rate was 98.2% after 70 min irradiation over Co2+-doped Bi 2 O 3. Although h+, ∙O 2 –, and ∙OH were detected in the photocatalytic process, the dominant active species was h+. In addition, three degradation pathways containing 12 intermediates were proposed. [ABSTRACT FROM AUTHOR]

Abstract: We described a two-step process to fabricate the heparinized polypropylene (PP) film using cyanuric chloride (CC) as a trifunctional reagent and poly (ethylene glycol) methacrylate (PEGMA) as a spacer. The modified PP films were characterized by attenuated total reflectance FT-IR and X-ray photoelectron spectroscopy; the content of PEGMA and heparin were determined by gravimetric method and a toluidine blue assay, respectively. For the PP-g-PEGMA films, it was found that small size protein BSA tended to adsorb on the surface of low molecular weight monomer grafted PP, whereas big spindle-shaped fibrinogen tended to adsorb on the surface of high molecular weight monomer grafted PP. We gave a definition of anti-protein adsorptive factor r with two model proteins, albumin and fibrinogen. The results by platelet adhesion and plasma recalcification time (PRT) experiments indicated that the factor r could be used to quantitatively evaluate the anticoagulant tendency of PP-g-PEGMA modified films. For the PP-g-PEGMA-g-heparin modified films, the surface was proved to have a high bioactivity by the adsorption of AT III assay and very low platelet adhesion. It indicated that immobilization of heparin on the PP film with PEGMA as a spacer was an effective way to improve the hemocompatibility of PP. [Copyright &y& Elsevier]

Abstract: Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalently grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiated graft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified by ATR–FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiation time and initiator concentration on the grafting density was investigated. Comparing with the virgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surface energy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-protein adsorption to the SEBS surface. [Copyright &y& Elsevier]

Abstract: In this study, 304 stainless steel coatings were deposited on interstitial-free steel substrate by cold spraying method. The effect of annealing treatment on microstructure, microhardness, ultimate tensile strength and fracture performance of the coatings were studied. The results showed that annealing treatment had made a dominant contribution to heal up the incomplete interfaces between the deposited particles. Both of the microstructure and the mechanical properties have been obviously optimized by annealing treatment. In addition, the coating microhardness decreased from 345 HV0.2 for the as-sprayed coating to 201 HV0.2 for the annealed coating. The coating ultimate tensile strength increased from 65MPa for the as-sprayed coating to 357MPa for the annealed coating, which resulted from the increase of the metallurgically bonded areas in the coating induced by annealing treatment. Fracture morphology of the coatings also revealed that annealing treatment changed the fracture character of the cold sprayed 304 stainless steel coating from brittle type to plastic type. [Copyright &y& Elsevier]

Abstract: A stable organic solar cell with structure of ITO/buffer/donor/acceptor/cathode is presented. A thin layer (5nm) of MoO3-doped CuPc is adopted as the buffer in CuPc/C60 organic heterojunction photovoltaic (PV) solar cells, resulting in two times longer lifetime. The surface morphology of buffer layer plays a decisive role in improving the stability. [Copyright &y& Elsevier]

• The optimized MoCoSe x @NC is prepared by a facile two-step method. • The uniform NC provides the growth space and fast electron transfer of active sites. • Mo doping can improve the intrinsic activity of CoSe x for HER. • The obtained MoCoSe x @NC exhibits excellent activity and stability for HER. Transition metal selenides have attracted wide attention owing to the unique structure and electron distribution in the field of electrocatalysis. However, adopting the suitable strategy to further improve the intrinsic activity and exposure of transition metal selenides is still a challenge. Herein, the optimized MoCoSe x encapsulated in N–doped hollow carbon nanosphere (MoCoSe x @NC) has been synthesized for hydrogen evolution reaction (HER) through a simple two–step method. Firstly, the uniform porous NC has been obtained through carbonization at 900 °C, which provides the growth space and fast electron transfer of active sites. Secondly, the optimized MoCoSe x @NC with excellent dispersion has been synthesized through the following hydrothermal process. Moreover, the synergistic effect of Mo doping can improve the intrinsic activity of CoSe x for HER. The obtained MoCoSe x @NC exhibited excellent low over potential of 60 mV at 10 mA cm−2 and great stability for HER. The enhanced activity may attribute to the good dispersion of MoCoSe x and NC substrate. After optimized synthesis process, we found that the first carbonization of NC is the base for constructing the good dispersion of MoCoSe x. This work provides a new design strategy for transition metal selenides supported on carbon substrate as electrocatalysts for HER. [ABSTRACT FROM AUTHOR]

• Co 3 O 4 crystals with different shapes and surface structures were synthesized. • Catalysis of the Co 3 O 4 crystals in persulfate was structure-dependent. • The Co 3 O 4 nanocubes had the highest catalytic activity in persulfate activation. • 1O 2 was dominantly contributed to the OG degradation. • The exposed plane of (1 1 1) was responsible for 1O 2 generation. Co 3 O 4 crystals with different shapes and surface structures were successfully synthesized. The shapes obtained included flower-like nanoplates (FN), nanocubes (NC), nanosheets (NS) and flake-stacked microsphere (FM). The shapes and surface structures of the Co 3 O 4 catalysts significantly affected their catalytic activity. Among the as-synthesized Co 3 O 4 catalysts, the NC sample displayed the highest catalytic activity in persulfate (PS) activation, achieving almost complete removal of 30 mg L−1 orange G (OG) within 10 min at the reaction conditions of 0.5 g L−1 catalyst and 8.0 mM PS. The excellent catalytic performance of NC sample could be ascribed to dominant exposed crystal plane and abundant surface hydroxyl groups. The electron paramagnetic resonance (EPR) and radical quenching tests demonstrated that reactive oxygen species (ROS) including sulfate radical (· SO 4 −), hydroxyl radical (· OH), superoxide radical (· O 2 –) and singlet oxygen (1O 2) were generated in the NC/PS system, while 1O 2 was dominantly attributed to the OG degradation. The exposed plane of (1 1 1) may be responsible for the generation of 1O 2. The study dedicates a novel mechanism of PS heterogeneous activation by Co 3 O 4 crystals and provides an ideal catalyst for efficient removal of organic pollutants in wastewater. [ABSTRACT FROM AUTHOR]

• Voids are introduced into AlN film grown on FSS through growth mode transition. • Dislocation filter and strain relief are achieved with the introducing of voids. • A 3 μm-thick AlN film grown on FSS using this strategy is nearly stress free. We demonstrate the achieving of high-quality AlN films on flat sapphire substrate (FSS) by introducing voids during growth. Voids are embedded into AlN epilayers through a growth-mode transition from island growth to step flow growth. Such voids significantly facilitated the underlying dislocations annihilation as demonstrated by the transmission electron microscopy (TEM) image. For the 3 μm-thick AlN film grown on FSS, the full width at half maximum of the X-ray rocking curve was 57/260 arcsec for (0 0 2)/(1 0 2) reflection and a threading dislocation density of 1.7 × 108 cm−2 was determined from plain-view TEM image. Moreover, the voids provided an additional stress relief channel in the AlN film grown on FSS, resulting in a tensile stress comparable to that of grown on nano-patterned sapphire substrate (NPSS). The measured lattice constants and Raman shift of AlN-E 2 (high) peak verified the 3 μm-thick AlN film grown on FSS is nearly stress free at room temperature. Taking advantages of the deliberately embedded voids, a crack-free and atomically flat AlN film was grown on FSS. The strategy put forward in this work to obtaining high-quality AlN films on FSS is much cost-efficient, which is believed to hold great promise for commercialization in AlN-based devices. [ABSTRACT FROM AUTHOR]

• N-doped TiO 2 @rGO nanotubes were prepared by annealing GO-coated H-titanate nanotubes in ammonia. • The composite absorbs nearly the full visible-light spectrum. • Without Pt as a cocatalyst, the H 2 production rate is as high as 720 µmol g−1 h−1. • Even one year, the surface Ti3+'s concentration exhibits no distinct decrease. Due to the merits of visible-light absorption and high conductivity, Ti3+ is a main focus among the modifications of TiO 2. However, surface Ti3+ is unstable. Herein, surface-stable Ti3+ in an N-doped rGO-coated TiO 2 nanotube sample is prepared. The N-doping introduced Ti-C bonds and an abundance of surface Ti3+, which produced several mid-gap states. These properties allow the composite to absorb nearly the full visible-light spectrum. Owing to the advantages of a broad visible-light absorption, short diffusion distance in the nanotube, and a good heterojunction, the composite exhibits a good photocatalytic activity. Under visible light and without Pt as a cocatalyst, methylene blue was degraded within 40 mins, and the H 2 production rate is as high as 720 µmol g−1 h−1. Due to the synergistic effect of N doping and Ti-C bond formation, the configuration of surface Ti3+ is stabilized by a charge-transfer resonance mechanism. The tightly coated graphene also plays a vital role in protecting the surface Ti3+. Even after storage for one year, the photocatalytic activity and the EPR signal intensity from Ti3+ paramagnetic states remain unchanged within experimental error. It suggests that the surface Ti3+ concentration, and the properties of the composite are stable with time. [ABSTRACT FROM AUTHOR]