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Highlights • The NiCo 2 O 4 and NiCo 2 O 4 @MnO 2 composites synthesized by a hydrothermal method. • NiCo 2 O 4 @MnO 2 maintained reversible capacities of 1000 mA h g−1 after 100 cycles. • NiCo 2 O 4 @MnO 2 electrodes demonstrated an enhanced rate performance. Abstract 3D flower-like NiCo 2 O 4 and NiCo 2 O 4 @MnO 2 were successfully synthesized via a hydrothermal method. Scanning electron microscopy results illustrated that NiCo 2 O 4 is formed by stacking nanosheets, and after reaction in KMnO 4 solution, MnO 2 were evenly coated on the surface of NiCo 2 O 4 formed flower-like structure. The as-synthesized materials were evaluated as an anode materials for lithium-ion batteries, NiCo 2 O 4 and NiCo 2 O 4 @MnO 2 exhibited high specific capacities of 841.9 and 1 000 mA h g−1 after 100 cycles respectively. Moreover, NiCo 2 O 4 @MnO 2 composites demonstrate good rate performance. These enhanced electrochemical properties could be attributed to the distinctive 3D flower-like structure, which increases the contact area between the electrolyte and electrode material to provide more active sites, and reduced volume effects during repeated insertion/extraction of lithium ions. The results suggest that the NiCo 2 O 4 @MnO 2 composites could be promising LIBs anode materials. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The complete hollow ZnFe 2 O 4 nanospheres were synthesized just by a simple solvothermal process. • The nanospheres show huge and complete inner space with a diameter of 180 nm. • The ZnFe 2 O 4 electrode delivers a capacity more than 1100 mAh·g−1 at 200 mA·g−1 after 120 cycles. • The electrochemical properties of the ZnFe 2 O 4 nanospheres are even superior than many reported composites. Abstract Complete hollow ZnFe 2 O 4 nanospheres with well crystallization and uniform dispersion were successfully synthesized via a facile solvothermal method. The obtained ZnFe 2 O 4 material displays a complete hollow sphere structure with a huge interspace diameter of 180 nm. When used as anodes for lithium ion battery, the as-prepared sample exhibits high initial discharge/charge capacities of 1321.4/976.8 mA h·g−1 at 100 mA·g−1, with an initial Coulombic efficiency reaching as high as 73.9%. Surprisingly, the specific capacity of ZnFe 2 O 4 electrodes experiences a process of decrease in initial 20 cycles and stable increase in subsequent 100 cycles, with a considerable discharge capacity of 1101.3 mA h·g−1 at 200 mA·g−1 after 120 cycles. Even at a high rate of 1600 mA·g−1, the capability for electrodes still maintains at 703.6 mA h·g−1, much larger than traditional commercialized graphite anode (372 mA h·g−1). Such remarkable electrochemical properties of the only ZnFe 2 O 4 material are even superior than those complex and expensive ZnFe 2 O 4 -based composites reported previously. It is believed that zinc ferrite nanosphere material with high reversible capacity, favorable cycling stability and good rate capability holds promise for becoming an alternative anode of lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Vanadium dioxide (VO 2 ) has a fantastic phase transition behavior from insulator to metal which could be used for numerous areas. Research on the optical constant and fine structure of VO 2 at various temperatures is favorable to investigate the mechanism of phase transition, and benefits the design and fabrication of vanadium dioxide integrated devices or applications. So the micro structure variation and evolution process during the transformation of VO 2 thin film which deposited via DC reactive magnetron sputtering method was characterized by temperature-dependent spectroscopic ellipsometry and Raman spectroscopy, along with X-ray diffraction. It could be observed that the Raman scattering peaks decreased corresponded with temperature, as well as the blue shift and red shift occurred in V–V vibration (@192 cm −1 ) and V–O vibration (@613 cm −1 ), respectively. The result revealed the M 1 phase to R phase transform process of VO 2 film. The refraction index determined by ellipsometry keep almost stable in ultraviolet and visible wavelength at various temperatures, but show abrupt decline at MIT temperature in near-infrared wave band. Moreover, the tendency of temperature-dependent refraction index at 990 nm match well with the sheet resistance which could be described by Boltzmann model. [ABSTRACT FROM AUTHOR]

A free-standing Si@Co 9 S 8 CF electrode with excellent rate capability and cycling performance was obtained by electrospinning, vulcanization, and carbonization processes as high-performance anode for Li-ion batteries. [Display omitted] • Si@Co 9 S 8 CF films are explored by electrospinning, vulcanization and carbonization. • The yolk-shelled Si@Co 9 S 8 can remarkably alleviate the volume expansion. • The introduction of CFs can improve the electrical conductivity of the electrodes. • The free-standing anode avoids the conventional process of electrode preparation. Silicon-based (Si-based) materials have aroused extensive attention owing to their ultra-high theoretical specific capacity, while the huge volume expansion and inferior electronic conductivity have impeded their practical application in lithium-ion batteries (LIBs). Rational structural design has been regarded as a fascinating strategy, especially for yolk-shell structures. Herein, Si nanoparticles (Si NPs) were encapsulated in ZIF-67 metal–organic frameworks to obtain Si@ZIF-67 particles, which were wrapped in one-dimensional carbon fibers (CFs) by simple processes of electrospinning, vulcanization and carbonization to obtain a free-standing Si@Co 9 S 8 CF electrode. The yolk-shelled Si@Co 9 S 8 particles could remarkably ameliorate the volume variation of Si materials during the lithiation/de-lithiation cycling and the introduction of CFs endowed an efficient one-dimensional electronic pathway accurately to improve the conductivity of composite materials. In addition, it was not negligible that the as-obtained Si@Co 9 S 8 CF films could be as a self-supporting electrode, which avoided the traditional cumbersome procedure of the electrode preparation. The resulting composite electrodes possess an excellent rate performance and an ultra-stable cycling lifespan. We hope this work can provide some novel insights for the development of the self-supporting Si-based electrode materials. [ABSTRACT FROM AUTHOR]

Novel hierarchical flower-like Sn 3 O 4 assembled by thin Sn 3 O 4 nanosheets , as a kind of mixed-valence tin oxide, decorated on two-dimensional graphene nanosheets has been synthesized via a hydrothermal route and a step solution deoxidization technique. More importantly, as the anode materials for lithium ion batteries, the flower-like Sn 3 O 4 /graphene composite has not been investigated in detail. Noticeably, the nanosheets stemming from flower-like Sn 3 O 4 and graphene have been linked together to form a specials three dimensional structure, possessing high active surface area and large enough inner spaces, which is benefit to the diffusion of liquid electrolyte into the electrode materials. In addition, the special structure could provide sufficient free volume to buffer the volume expansion appeared in the process of discharging and charging. The as-prepared flowers-like Sn 3 O 4 /graphene displayed excellent electrochemical performance with high capacity and good cycling stability as anode materials for lithium ion batteries. The discharge capacity is 1727 mAh/g in the first cycle at the current density of 60 mA/g. The obtained reversible capacity is 631mAh/g with a coulomb efficiency of 97.04% after 50 cycles. With its better electrochemical properties, the as-prepared flowers-like Sn 3 O 4 /graphene has the potential to be the next generation materials as an environmentally benign, abundant, cheap anode materials for lithium ion batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ti 3 C 2 T x /g-C 3 N 4 flexible free-standing electrode was prepared and show excellent performance. • Flexible solid-state supercapacitors were assembled and can work stably even in the 180° bending state. • DFT calculation was performed to reveal the mechanism of enhanced electrochemical performance of Ti 3 C 2 T x /g-C 3 N 4 heterostructure. With the popularity of intelligent portable electronic devices, bendable and flexible electronic equipment, such as portable miniature devices, wearable electronics, smart clothing, electronics, display, skin flexible smartphones and implantable medical devices have become a development trend. As potential energy storage device, flexible supercapacitors have attracted extensive attention. Ti 3 C 2 T x MXenes, which has high capacitance, mechanical strength and flexibility, perfectly meets the requirements of flexible energy storage devices. In order to avoid stacking, increase layer spacing, and enhance charge transfer efficiency, the Ti 3 C 2 T x /g-C 3 N 4 heterostructure is constructed by self-assembly method. The flexible self-supporting electrode is prepared by vacuum assisted filtration, which successfully widen the potential window and significantly improve the capacitance performance. The specific capacitance of the electrode in 1 M H 2 SO 4 electrolyte reaches 414 F/g at 1A/g. The electrode can simultaneously act as a fluid collector to construct a simple ultra-thin device. The flexible all-solid symmetric supercapacitor is assembled and the energy density reaches 23.98 Wh/Kg when the power density is 139.66 W/Kg. Encouragingly, the device can maintain stable performance under 180° bending conditions. The above excellent performance confirms the applicability of supercapacitors based on Ti 3 C 2 T x /g-C 3 N 4 heterostructure films for future portable, flexible or wearable electronic energy storage devices. [ABSTRACT FROM AUTHOR]

In this work, NiO@MnO 2 core/shell nanocomposites were fabricated by a two-step method. The morphology and structure of the nanocomposites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction analysis and thermal gravity analysis. In addition, the supercapacitive performances were examined by cyclic voltammogram (CV), galvanostatic charge–discharge and electrochemical impedance spectroscopy (EIS). The electrochemical results indicate that the composite exhibits a specific capacitance of 266.7 F g −1 at 0.5 A g −1 and excellent cycling stability (81.7% retention after 2000 cycles at 1 A g −1 ). Therefore, this wok offers meaningful reference for supercpacitor applications in the future. [ABSTRACT FROM AUTHOR]

The electromagnetic wave absorption properties of the quaternary composites consisting of reduced graphene oxide (rGO), polyaniline (PANI), FeNi 3 @SiO 2 (FeNi 3 nanocrystals encapsulated in SiO 2 ) nanoparticles had never been reported. In this case, we prepared FeNi 3 @SiO 2 @rGO–PANI quaternary composites and TEM results shows spherical nanoparticles are well distributed on the surface of rGO–PANI nanosheets. The investigation of the electromagnetic wave absorbability reveals that the quaternary composites exhibit wide absorption bandwidth and enhanced electromagnetic wave absorption properties. The absorption bandwidth with reflection loss less than −10 dB (90% attenuation) is up to 6.64 GHz (10.08–10.80 GHz, 12.08–18.0 GHz), and the maximum reflection loss reaches about −40.18 dB at 14.0 GHz with the thickness of 2.4 mm. It is believed that the FeNi 3 @SiO 2 @rGO–PANI composites can serve as excellent electromagnetic wave absorbent and can be widely used in practice. [ABSTRACT FROM AUTHOR]

Superhydrophobic aluminum alloy surfaces are obtained by chemical etching using 1 M NaOH solution followed by passivation using 0.01 M ethanolic stearic acid (SA) solution. The formation of low surface energy aluminum stearate takes place during the passivation process between stearic acid and hydroxyl group-terminated aluminum alloy surfaces. A schematic model of the SA passivation process on the OH terminated Al-surfaces is presented in this work. The flake-like micro-nanostructure morphology of the low surface energy aluminum stearate increases the water contact angle by more than 150°, demonstrating the superhydrophobic properties. The corrosion current density reduces and polarization resistance increases systematically with increasing passivation time. The polarization resistance, calculated from the Tafel curve of the superhydrophobic surfaces prepared by stearic acid passivation for 60 min, is determined to be 137 times larger than that of the as-received aluminum alloy substrate. Similarly, the modulus of impedance, as-determined from electrochemical impedance spectroscopy (EIS), is found to be 70 times larger for the superhydrophobic surfaces compared with the as-received aluminum alloy surface. These results demonstrate that the superhydrophobic aluminum alloy surfaces created by chemical etching followed by passivation have superior corrosion resistance properties than the as-receive aluminum alloy substrate. [ABSTRACT FROM AUTHOR]

The reduced graphene oxide (RGO)-CoFe 2 O 4 composite was synthesized by a facile route. The morphology, microstructure and microwave electromagnetic properties of the composite were detected by means of XRD, TEM, SEM, XPS TGA, VSM and vector network analyzer. The maximum reflection loss ( R L ) of the RGO-CoFe 2 O 4 reaches −44.1 dB at 15.6 GHz with a thickness of 1.6 mm, and the absorption bandwidth with the R L below −10 dB is up to 4.7 GHz (from 13.3 to 18.0 GHz) with a thickness of only 1.5 mm. The result demonstrates that the RGO plays a significant role in the microwave absorption proprieties of the RGO-CoFe 2 O 4 composite. It is believed that such composite will be applied widely in microwave absorbing area. [ABSTRACT FROM AUTHOR]

Superhydrophobic thin films have been fabricated on aluminum alloy substrates by electrophoretic deposition (EPD) process using stearic acid (SA) functionalized zinc oxide (ZnO) nanoparticles suspension in alcohols at varying bath temperatures. The deposited thin films have been characterized using both X-ray diffraction (XRD) and infrared (IR) spectroscopy and it is found that the films contain low surface energy zinc stearate and ZnO nanoparticles. It is also observed that the atomic percentage of Zn and O, roughness and water contact angle of the thin films increase with the increase of the deposited bath temperature. Furthermore, the thin film deposited at 50 °C, having a roughness of 4.54 ± 0.23 μm, shows superhydrophobic properties providing a water contact angle of 155 ± 3° with rolling off properties. Also, the activation energy of electrophoretic deposition of stearic-acid-functionalized ZnO nanoparticles is calculated to be 0.5 eV. [ABSTRACT FROM AUTHOR]

A high-performance flexible Zn-ion hybrid supercapacitor was fabricated by an adjustable structural optimization, and the potential practical value of the flexible all-solid-state hybrid supercapacitor was demonstrated. [Display omitted] • A zinc-ion hybrid supercapacitor derived from biomass carbon is fabricated. • The supercapacitor exhibits desirable flexibility and long cycling stability. • The remarkable performance is related to structural design. • A typical FZHSC device shows the potential practical application. The demand for developing sustainable energy storage renders biomass-based electrode materials a timely and important goal. However, the desirable electrochemical performance of the supercapacitor has still been hindered by insufficient contact chance between the active material and the electrolyte when both energy density and power density are required. Herein, the porous bamboo carbons were managed and used as the cathode to construct a flexible and high-performance Zn-ion hybrid supercapacitor (ZHSC) by combining the merit of capacitor-type and battery-type electrode materials. The porous material with high porosity is obtained via a controllable structural optimization. Consequently, the as-constructed hybrid supercapacitor delivers a superior specific capacitance of 321.3F g−1 at 1 A g−1 together with a high energy density of 114.2 Wh kg−1 when the power density is 800.0 W kg−1. Meanwhile, the assembled flexible hybrid supercapacitor displays remarkable cycling stability with 78% capacitance retention after 20,000 cycles and enough to suffer various deformations with no noticeable degradation of capacitance. Finally, the potential practical value of the flexible hybrid supercapacitor is demonstrated by an eye-catching orbital diagram. This work reveals that the flexible supercapacitor mainly constructed by porous biomass carbon is a promising candidate for energy storage devices. [ABSTRACT FROM AUTHOR]

Highlights: [•] Superhydrophobic copper surfaces by a one-step electrochemical modification process in an ethanolic stearic acid solution. [•] Analysis of the corrosion properties of as-received, hydrophobic and superhydrophobic copper surfaces. [•] The corrosion resistance of the superhydrophobic surface is found to be 1220kΩcm2 as compared to as-received bare copper surface 1kΩcm2. [Copyright &y& Elsevier]

Abstract: The nanocomposite of hard (BaFe12O19)/soft ferrite (Ni0.8Zn0.2 Fe2O4) was prepared by the sol–gel process, and then the polyaniline(PANI)/polypyrrole(PPY)-BaFe12O19/Ni0.8Zn0.2Fe2O4 was produced by in situ polymerization method. The structures, morphology and electromagnetic properties of the samples were characterized by various instruments. XRD, TEM, and FTIR analysis indicated that BaFe12O19/Ni0.8Zn0.2Fe2O4 ferrite were homogenously enwrapped by PANI(PPY) coating. The VSM and SDY-4 measurement show that the magnetic properties of the composites decreased with the increase in PANI(PPY) amount, However, the electrical conductivity is on the contrary. The electromagnetic properties of the composites were much better than BaFe12O19/Ni0.8Zn0.2Fe2O4 in the frequency range of 2–15GHz, which mainly depends on the dielectric loss of PANI(PPY). A minimum reflection loss of the PANI(PPY)-BaFe12O19/Ni0.8Zn0.2Fe2O4 ferrite nanocomposite is −19.7dB(−21.5dB) at the frequency of 7.3GHz (10.7GHz). [Copyright &y& Elsevier]

Abstract: The nanocomposites Li2SnO3/polyaniline (Li2SnO3/PANI) have been synthesized by a micro emulsion polymerization method. The structure, morphology and electrochemical properties of the as-prepared materials are characterized by XRD, FTIR, Raman, XPS, TGA, TEM and electrochemical measurements. Results show that Li2SnO3/PANI nanocomposites are composed of uniform and blocky nano-sized particles (40–50nm) with clear lattice fringes. Electrochemical measurement suggests that Li2SnO3/PANI exhibits better cycling properties and lower initial irreversible capacities than Li2SnO3 as negative electrodes materials for lithium-ion batteries. At a current density of 60mAg−1 in the voltage about 0.05–2.0V, the initial irreversible capacity of Li2SnO3/PANI is 563mAhg−1 while it is 687.5mAhg−1 to Li2SnO3. The capacity retained of Li2SnO3/PANI (569.2mAhg−1) is higher than that of Li2SnO3 (510.2mAhg−1) after 50 cycles. The PANI in the Li2SnO3/PANI nanocomposites can buffer the released stress caused by the drastic volume variation during the alloying/de-alloying process of Li–Sn. [Copyright &y& Elsevier]

Abstract: Composite Li2SnO3/C with good cycle performance for lithium-ion batteries was synthesized by a hydrothermal route. The structure, morphology and electrochemical properties of the as-prepared materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA) and electrochemical measurements. Results show that the length of the Li2SnO3 nanorods are in the range of 40–60nm while the average diameter is approximately 30nm. Amorphous carbons are distributed among the Li2SnO3 nanoparticles. The first discharge–charge capacities of Li2SnO3/C are 2045.8mAhg−1 and 1756.6mAhg−1. After the 50th cycles, the capacity retained is 598.3mAhg−1 at a constant current density of 60mAg−1 in the voltage range of 0.05–2.0V. The composite Li2SnO3/C exhibits a better electrochemical property than Li2SnO3. [Copyright &y& Elsevier]

Abstract: Strontium ferrite particles were firstly prepared by sol–gel method and self-propagating synthesis, and then the polyaniline/strontium ferrite/multiwalled carbon nanotubes composites were synthesized through in situ polymerization approach. Structure, morphology and properties of the composite were characterized by various instruments. XRD analysis shows that the output of PANI increases with the increase of the content of MWCNTs, due to the large surface area of MWCNTs. Because of the coating of PANI, the outer diameter of MWCNTs increases from 10nm to 20–40nm. The electrical conductivity of the composites increases with the amount increase of MWCNTs and reaches 7.2196S/cm in the presence of 2g MWCNTs. The coercive force of the composites prepared with 2g MWCNTs is 7457.17Oe, which is much bigger than that of SrFe12O19 particles 6145.6Oe, however, both the saturation magnetization and the remanent magnetization of the composite become much smaller than those of SrFe12O19 particles. The electromagnetic properties of the composite are excellent in the frequency range of 2–18GHz, which mainly depend on the dielectric loss in the range of 2–9GHz, and mainly on the magnetic loss in the range of 9–18GHz. [Copyright &y& Elsevier]

Abstract: BaFe12O19 nanowire arrays having single magnetic domain size (≤460nm) in anodic aluminum oxide (AAO) templates were prepared by sol–gel and self-propagating high-temperature synthesis techniques. The diameter of the nanowire arrays is approximately 70nm and the length is about 2–4μm. The specimens were characterized using X-ray diffraction, vibrating sample magnetometer, field emission scan electron microscope, atomic force microscopy and microwave vector network analyzer. The magnetic properties of BaFe12O19 nanowire arrays embedded in AAO templates were measured by VSM with a field up to 1274KA/m at room temperature. The results indicate that the nanowire arrays exhibit large saturation magnetization and high coercivity in the range of 6000Oe and an obvious magnetic anisotropy with the easy magnetizing axis along the length of the nanowire arrays, probably due to the shape anisotropy and magneto-crystalline anisotropy. Finally the microwave absorption properties of the nanowires were discussed. [Copyright &y& Elsevier]

[Display omitted] • The partly crosslinked polymer electrolyte presents a maximum conductivity of 1× 10−4 S·cm−1 at 30 °C and wide electrochemical window. • The LiFePO 4 ||Li cell exhibits excellent capacity retention of 91% after 100 cycles. • Satisfactory stability for NCM811||Li high-voltage lithium batteries. The Ti3+ doped TiO 2 nanowires were grafted by tolylene-2,4- diisocyanate (TDI) and applied as a modifier for the preparation of organic–inorganic hybrid electrolyte in high performing lithium batteries. The PEO-based polymer electrolyte was optimized at different organic–inorganic ratios and exhibited excellent lithium-ion conductivity of 1 × 10−4 S·cm−1 at 30 °C when adding 8% TDI-TiO 2 nanowires, outstanding electrochemical stability with a wide electrochemical window up to 5.5 V at 60 °C and a high lithium-ion transport number of 0.36. The LiFePO 4 |PTTNW8%|Li cells deliver excellent rate capability and cycling performance, with a high initial discharge capacity up to 151 mAh·g−1 at 60 °C at 0.1 C rate and excellent capacity retention of 91% after 100th cycle. NCM811|PTTNW8%|Li high-voltage lithium batteries were also demonstrated at a 50 °C, which displayed a superior cycling performance. Therefore, the prepared PEO-TDI-TiO 2 electrolyte is a promising polymer electrolyte for solid- state lithium batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] • The highlights of this work are as follows: • N-doped biochar derived from squid ink is premiere application for electrospinning. • Biochar composite with high-capacity used in flexible asymmetric supercapacitor. • The regulation of temperature and KOH content reveal the energy storage mechanism. Flexible supercapacitors have become a concern of flexible energy storage devices. In the process of exploring, the squid ink as N-doped biomass carbon was introduced to self-supporting flexible supercapacitors by electrospinning for the first time. By regulating the content of squid ink, the activation temperature, and the mass ratio of KOH-assisted activation, a N-doped porous biomass carbon@polyacrylonitrile (NPBC-1.5@PAN-800-2) with an ideal capacity and an excellent specific surface area (636.68 m2 g−1) was prepared. In addition, ZnO further optimized the capacity (422.7 F/g at 1 A g−1) and as an adhesive-free electrode for flexible asymmetric supercapacitor provided a relatively high specific capacitance, a satisfactory capacitance retention, and a wonderful energy density (48.01 Wh kg−1 at 1124.43 W kg−1). The capacitance was thought to originate from a suitable microporous structure, N-doped, and metal-derived pseudocapacitance propertie. [ABSTRACT FROM AUTHOR]

Highlights: [•] Graphene was grown on Cu foil by mobile thermal chemical vapor deposition system. [•] CNT was synthesized on graphene for RuO2 nanostructure growth by thermal chemical vapor deposition system. [•] The CNT growth location was fixed through the use of photolithography technique, thereby increasing the specific area. [•] RuO2 nanostructures were coated onto CNT bundle arrays through metal organic chemical vapor deposition, in order to utilize its pseudo capacitive property. [ABSTRACT FROM AUTHOR]

The synergistic effect of sodium and oxygen expands π-conjugated aromatic rings and distortion of the heptazine skeleton, enhancing the intrinsic π→π* electron transition and the effective n→π* electron transition. [Display omitted] • A sodium and oxygen co-doped g-C 3 N 4 (NaOCN) is prepared by facile microwave synthesis, in which Na as a charge transport channel promotes the separation efficiency of photogenerated carriers. • The as-prepared NaOCN exhibits the NIR absorption extended to 1400 nm and the apparent quantum yield (AQY) can keep 26.9% at 420 nm and still maintain 7.2 % at 600 nm, which shows strong NIR response range. • The intrinsic π → π* electron transition and active the n → π* electron transition generated by the synergistic effect of Na and O atoms are the main factor to promote the NIR response of NaOCN. Efficient utilization of near-infrared light (NIR) is critical to optimize the performance of photocatalysts. Herein, an ultrafast process is employed to co-condensation of melamine and NaCl by microwave-assist heating. The fabricated sodium and oxygen co-doped g-C 3 N 4 (NaOCN) shows extended π-conjugated aromatic rings and distortion of the heptazine skeleton, which can enhance the intrinsic π → π* electron transition and active the n → π* electron transition. The robust n → π* excitation of NaOCN leads to a narrowed bandgap of 2.73 eV with the NIR absorption extending to 1400 nm. The apparent quantum yield (AQY) for NaOCN can still keep 7.2 % at 600 nm. This work provides a promising way for the application of NIR-based carbon nitride in photocatalytic H 2 O 2 production. [ABSTRACT FROM AUTHOR]

Graphical abstract We investigated electron transfer during the time-dependent binding processes between thiolate molecules and Au nano-islands by observing tunneling current with an interdigitated microelectrode supporting the sputtered Au nano-islands (IME@AuNI). Thiolate molecules could capture partial free electrons of the Au nano-islands, which affects the tunneling current among Au nano-islands. Furthermore, the spectral and current characteristics depended on the thiolate structure, because of the formation of capping layer in accordance with thiolate structure. Scheme 1. Electron transfer observation by using IME@AuNI. Highlights • We investigated electron transfer during the binding processes between thiolate molecules and Au nano-islands by observing tunneling current with IME@AuNI. • The spectral and current characteristics of IME@AuNI depended on the thiolate structure, because of the formation of capping layer in accordance with thiolate structure. • The current characteristics are mainly attributed to synergistic effects of electron transfer and bridging effects of thiolate molecules among Au nano-islands. Abstract We investigated electron transfer during the time-dependent binding processes between thiolate molecules and Au nano-islands by observing tunneling current with an interdigitated microelectrode supporting the sputtered Au nano-islands (IME@AuNI). The time-dependent optical and electrical signal variation during the binding process was examined for five kinds of thiolates. As the immersion time was prolonged, the optical absorbance increased, whereas the current passing through the IME@AuNI decreased. Importantly, the spectral and current characteristics depended on the thiolate structure, because of the formation of capping layer in accordance with thiolate structure. These results are mainly attributed to synergistic effects of electron transfer from Au nano-islands to thiolate molecules and bridging effects of thiolate molecules among Au nano-islands. [ABSTRACT FROM AUTHOR]

This paper demonstrates an ethanol gas sensor based on indium oxide/molybdenum disulfide (In 2 O 3 /MoS 2 ) nanocomposite via hydrothermal route. The microstructure and micromorphology of In 2 O 3 /MoS 2 nanocomposite were fully characterized by various analytical techniques. The gas-sensing properties of the In 2 O 3 /MoS 2 composite were investigated upon exposure to different concentrations of ethanol gas from 1 ppm to 50 ppm at the optimum temperature, and compared with the pristine In 2 O 3 sensors. Owing to the supporting substrate of specific two-dimensional MoS 2 nanosheets, the sensor based on In 2 O 3 /MoS 2 composite exhibit superior gas sensing performance towards ethanol, which outstripped that of pure In 2 O 3 sensor and have potential applications in the detection of ethanol vapors. [ABSTRACT FROM AUTHOR]

The carbon nanotube (CNT) has replaced palladium oxide (PdO) as the electrode material for surface-conduction electron-emitter (SCE) applications. Vertically aligned CNT arrays with a delta-star arrangement were patterned and synthesized onto a quartz substrate using photolithography and thermal chemical vapor deposition. Delta-star shaped VACNT arrays with 20° tips are used as cathodes that easily emit electrons because of their high electrical field gradient. In order to improve the field emission and secondary electrons (SEs) in SCE applications, magnesium oxide (MgO) nanostructures were coated onto the VACNT arrays to promote the surface-conduction electron-emitter display (SED) efficiency (η). According to the definition of η in SCE applications, in this study, the η was stably maintained in the 75–85% range. The proposed design provides a facile new method for developing SED applications. [ABSTRACT FROM AUTHOR]

Amorphous carbon nanorods (CNRs) were deposited directly using radio frequency magnetron sputtering. The synthesized CNR electrochemical properties were investigated using graphene as the current collector for an electric double layer capacitor. The CNRs were vertically aligned to the graphene to achieve higher specific surface area. The capacitor performance was characterized using electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic charge-discharge testing in 1 M KOH electrolyte at 30°C, 40°C, 50°C, and 60°C. The CNR specific capacitance was observed to increase with increasing measurement temperature and could reach up to 830 F/g at 60°C. Even after extensive measurements, the CNR electrode maintained good adhesion to the graphene current collector thereby suggesting electrode material stability. [ABSTRACT FROM AUTHOR]

Abstract: Carbon nanotubes (CNTs) were used as the electric double layer capacitor (EDLC) material and were synthesized by using thermal chemical vapor deposition (TCVD). To enhance the EDLC capacity, the ruthenium dioxide (RuO2) nanorods were grown on CNTs by using metal organic chemical vapor deposition (MOCVD). The synthesized CNTs were the principal part and template, and the RuO2 nanorods were grown outwardly from CNTs. The increase of effective specific area between electrode and electrolyte played an important role in enhancing the capacitance. Different concentrations of KOH were used as electrolyte to measure the capacitance to find the variation of capacitance. Moreover, the RuO2/CNT composites demonstrated a stable cycle life. The results showed that the RuO2/CNT composites were a promising supercapacitor device material. [Copyright &y& Elsevier]

A morphology-controllable 0D/1D g-C 3 N 4 (CN) homojunction using the melamine-cyanuric acid supramolecular (MCS) and urea as co-precursor was constructed by a facile in-situ thermal polymerization process. [Display omitted] • A morphology-controllable 0D/1D g-C 3 N 4 homojunction (MUCN) was constructed by a facile in-situ thermal polymerization process. • The as-prepare MUCN is stable with controllable and uniform morphology and exhibits significantly enhanced photocatalytic activities for RhB degradation and H 2 O 2 production. • The significantly enhanced photocatalytic performance of MUCN is attributed to the synergetic effect of energy band controlling and structural coupling in MUCN. • The results have provided a new effective way for promoting the practical photocatalytic application of CN. A morphology-controllable 0D/1D graphitic carbon nitride (g-C 3 N 4 , CN) homojunction (MUCN) was constructed by a facile in-situ thermal polymerization process using the melamine-cyanuric acid supramolecular (MCS) and urea as co-precursor. The as-prepare MUCN is stable with controllable and uniform morphology and exhibits significantly enhanced photocatalytic activities for RhB degradation and H 2 O 2 production. The RhB degradation rate and the H 2 O 2 production are ~37 times and 17 times higher than that of pure CN, respectively. The significantly enhanced photocatalytic performance is attributed to the synergetic effect of energy band controlling and structural coupling in MUCN, which can form the internal driving force to improve the separation efficiency of charge carriers. The results have provided a new effective way for promoting the practical photocatalytic application of CN. [ABSTRACT FROM AUTHOR]

Abstract: The RuO2 nanorods array is grown selectively on the SiO2-patterned sapphire (SA) wafers using reactive sputtering. The area-selectivity is attributed to an early nucleation of RuO2 and its fast surface coverage on SA (100) and (012), in contrast to the sluggish nucleation on glassy SiO2 in the initial sputtering period. The growth domain is explored by investigating the temperature windows at sputtering power 40, 50, and 60W. The low-temperature bound is limited by the mobility of precursors on SiO2 surface, which enables the precursors to depart before aggregating into a large size to smear the non-growth region. The high-temperature bound is set by the horizontal growth which enlarges the rod width and deteriorates its one-dimensional feature. The temperature window shrinks with increasing sputtering power. The X-ray photoelectron spectra indicate the as-sputtered rod surface is ruthenium rich. The X-ray diffraction analysis shows that RuO2 growth on SA (100) and (012) follows the epitaxial relations between RuO2 and SA crystals. [Copyright &y& Elsevier]

Two kinds of three-dimensional flower-like structure of nickel matrix composite electrodes with activated carbon (AC) or 50 nm carbon (C) particles have been successfully synthesized by a facile one-step composite electrodeposition process in a deep eutectic solvent (DES). The effects of different carbon materials and concentrations on the morphology and composition of composite coatings were systematically investigated. The formation mechanism of the composite coatings was proposed. The electro-catalytic activity of the deposited Ni matrix composite coatings containing AC or 50 nm C particles for hydrogen evolution reaction (HER) was also evaluated and compared. The results implied that the Ni matrix composite coatings incorporating with either AC or 50 nm C particles exhibited improved active surface area and higher catalytic activity for HER. Briefly, the overpotential can reach a value of 114 mV at the current density of 10 mA cm−2 in 1 M KOH, with the Tafel slope reaching 73.8 mV dec−1. This work provides a promising electrolyte and a facile strategy to design and prepare non-noble metal materials in catalysis field. Unlabelled Image • Three-dimensional flower-like structure of Ni-carbon composites have been electrodeposited. • The deposited Ni-carbon composites exhibit improved catalytic activity for hydrogen evolution reaction. • Ionic liquids show a promising application prospect for composite electrodeposition. [ABSTRACT FROM AUTHOR]