Mao-xiang Jing

High performance of carbon nanotubes/silver nanowires-PET hybrid flexible transparent conductive films via facile pressing-transfer technique

To obtain low sheet resistance, high optical transmittance, small open spaces in conductive networks, and enhanced adhesion of flexible transparent conductive films, a carbon nanotube (CNT)/silver nanowire (AgNW)-PET hybrid film was fabricated by mechanical pressing-transfer process at room temperature. The morphology and structure were characterized by scanning electron microscope (SEM) and atomic force microscope (AFM), the optical transmittance and sheet resistance were tested by ultraviolet-visible spectroscopy (UV-vis) spectrophotometer and four-point probe technique, and the adhesion was also measured by 3M sticky tape. The results indicate that in this hybrid nanostructure, AgNWs form the main conductive networks and CNTs as assistant conductive networks are filled in the open spaces of AgNWs networks. The sheet resistance of the hybrid films can reach approximately 20.9 to 53.9 Ω/□ with the optical transmittance of approximately 84% to 91%. The second mechanical pressing step can greatly reduce the surface roughness of the hybrid film and enhance the adhesion force between CNTs, AgNWs, and PET substrate. This process is hopeful for large-scale production of high-end flexible transparent conductive films.

Electrospinning preparation of oxygen-deficient nano TiO 2-x /carbon fibre membrane as a self-standing high performance anode for Li-ion batteries

Improving the specific capacity and electronic conductivity of TiO2 can boost its practical application as a promising anode material for lithium ion batteries. In this work, a three-dimensional networking oxygen-deficient nano TiO2-x/carbon fibre membrane was achieved by combining the electrospinning process with a hot-press sintering method and directly used as a self-standing anode. With the synergistic effects of three-dimensional conductive networks, surface oxygen deficiency, high specific surface area and high porosity, binder-free and self-standing structure, etc., the nano TiO2-x/carbon fibre membrane electrode displays a high electrochemical reaction kinetics and a high specific capacity. The reversible capacity could be jointly generated from porous carbon, full-lithiation of TiO2 and interfacial lithium storage. At a current density of 100u2009mAu2009g−1, the reversible discharge capacity can reach 464u2009mAu2009hu2009g−1. Even at 500u2009mAu2009g−1, the discharge capacity still remains at 312u2009mAu2009hu2009g−1. Compared with pure carbon fibre and TiO2 powder, the TiO2-x/C fibre membrane electrode also exhibits an excellent cycle performance with a discharge capacity of 209u2009mAu2009hu2009g−1 after 700 cycles at the current density of 300u2009mAu2009g−1, and the coulombic efficiency always remains at approximately 100%.

High loading LiFePO4 on activated carbon fiber cloth as a high capacity cathode for Li-ion battery

The LiFePO4/carbon fiber (LFP/CF) cathodes were prepared by using activated carbon fiber cloth as current collector in place of conventional Al foil. The electrochemical properties of LFP/CF electrodes were analyzed by the cyclic voltammetry and galvanostatic charge/discharge tests. The results indicate that the activated carbon fiber cloth with high specific surface area and high porosity makes the LFP/CF electrode that possesses higher mass loading of 18–21 mg cm–2 and stronger redox reaction ability compared with Al foil-based electrode. The LFP/CF electrode shows excellent rate performance and cycle stability. At 0.1C, the discharge capacity is up to 190.1 mAh g–1 that exceeds the theoretical capacity due to the combination effect of battery and capacitor. Furthermore, the LFP/CF electrode shows an initial capacity of 150.4 mAh g–1 at 1C with a capacity retention of 74.7% after 425 cycles, which is higher than 62.4% for LFP/Al foil electrode, and an initial discharge capacity of 130 mAh g–1 at 5C with a capacity retention of 61.5% after 370 cycles. But this composite electrode is not suitable for charging/discharging at higher rate as 10C due to too much mass loading.

Electrospinning fabrication of mesoporous nano Fe2O3-TiO2@activated carbon fiber membrane for hybrid removal of phenol from waste water

A mesoporous iron–titanium mixed-oxides@activated carbon(AC) fiber membrane was fabricated by an electrospinning method and applied to the treatment of phenol waste water. The physical and chemical properties of the composite fiber membrane were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption/desorption, UV–Vis light diffuse reflectance spectroscopy (DRS), Raman spectroscopy, respectively. The results indicate that the composite nanofiber membrane is composed of α-Fe2O3, anatase TiO2 and activated carbon phases with a specific surface area of 231 m2 g–1 and narrow pore size distribution of 3–6 nm. DRS reveals that the composite membrane has high photons absorption from both ultraviolet light and visible light irradiation owing to the combination of Fe2O3, TiO2 and carbon. The prepared nano Fe2O3–TiO2@AC fiber membrane can act as an efficient reusable photocatalyst and adsorbent for 100% remo val of phenol pollutant. This hybrid technique is hopeful to be widely used in the treatment of various organic waste waters.

Preparation and Properties of Double-Sided AgNWs/PVC/AgNWs Flexible Transparent Conductive Film by Dip-Coating Process

The double-sided transparent conductive films of AgNWs/PVC/AgNWs using the silver nanowires and PVC substrate were fabricated by the dip-coating process followed by mechanical press treatment. The morphological and structural characteristics were investigated by scanning electron microscope (SEM) and atomic force microscope (AFM), the photoelectric properties and mechanical stability were measured by ultraviolet–visible spectroscopy (UV–vis) spectrophotometer, four-point probe technique, 3M sticky tape test, and cyclic bending test. The results indicate that the structure and photoelectric performances of the AgNWs films were mainly affected by the dipping and lifting speeds. At the optimized dipping speed of 50xa0mm/min and lifting speed of 100xa0mm/min, the AgNWs are evenly distributed on the surface of the PVC substrate, and the sheet resistance of AgNWs film on both sides of PVC is about 60u2009Ω/sq, and the optical transmittance is 84.55xa0% with the figure of merit value up to 35.8. The film treated with the 10xa0MPa pressure shows excellent adhesion and low surface roughness of 17.8xa0nm and maintains its conductivity with the sheet resistance change of 17xa0% over 10,000 cyclic bends.

Electrospun LiFePO4/C Composite Fiber Membrane as a Binder-Free, Self-Standing Cathode for Power Lithium-Ion Battery

A LiFePO4/C composite fiber membrane was fabricated by the electrospinning method and subsequent thermal treatment. The thermal decomposition process was analyzed by TG/DSC, the morphology, microstructure and composition were studied using SEM, TEM, XRD, Raman, respectively. The results indicated that the prepared LiFePO4/C composite fibers were composed of nanosized LiFePO4 crystals and amorphous carbon coatings, which formed a three dimensional (3D) long-range networks, greatly enhanced the electronic conductivity of LiFePO4 electrode up to 3.59× 10-2 S · cm-2. The 3D LiFePO4/C fiber membrane could be directly used as a binder-free, self-standing cathode for lithium-ion battery, and exhibited an improved capacity and rate performance. The LiFePO4/C composite electrode delivered a discharge capacity of 116 mAh·g-1, 109 mAh·g-1, 103 mAh·g-1, 91 mAh·g-1, 80 mAh·g-1 at 0.1 C, 0.5 C, 1 C, 3 C, 5 C, respectively. And a stable cycling performance was also achieved that the specific capacity could retain 75 mA·g-1 after 500 cycles at 5 C. Therefore, this LiFePO4/C composite fiber membrane was promising to be used as a cathode for power lithium ion battery.

Synthesis of graphitic carbon nitride at different thermal-pyrolysis temperature of urea and it application in lithium–sulfur batteries

Graphitic carbon nitride (g-C3N4) was produced by the direct thermal-pyrolysis of urea at different temperatures without additive assistance. The physical properties of porous g-C3N4 were characterized by various measurement methods: X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area measurements, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ay photoelectron spectroscopy (XPS). The effect of thermal-pyrolysis temperature on electrochemical behaviors of was researched as the sulfur matrices in lithium–sulfur batteries. The g-C3N4 prepared at 550xa0°C with sulfur matrix exhibits the superior electrochemical performances. As the result, the sulfur/CN-550 composite cathode exhibits a high initial discharge capacity of 1262.1xa0mAhxa0g−1 and delivers a specific capacity of 605.4xa0mAhxa0g−1 over 500 cycles at 0.39xa0mAxa0cm−2. The excellent electrochemical behavior of the g-C3N4 could be ascribed to the effective utilization of sulfur and the combination of polysulfides dissolution through physical and chemical interactions to achieve long-term circulation of the composite cathode in lithium–sulfur batteries.

Synthesis and characterization of electrospun molybdenum dioxide–carbon nanofibers as sulfur matrix additives for rechargeable lithium–sulfur battery applications

One-dimensional molybdenum dioxide–carbon nanofibers (MoO2–CNFs) were prepared using an electrospinning technique followed by calcination, using sol–gel precursors and polyacrylonitrile (PAN) as a processing aid. The resulting samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Brunauer–Emmet–Teller (BET) surface area measurements, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). MoO2–CNFs with an average diameter of 425–575 nm obtained after heat treatment were used as a matrix to prepare sulfur/MoO2–CNF cathodes for lithium–sulfur (Li–S) batteries. The polysulfide adsorption and electrochemical performance tests demonstrated that MoO2–CNFs did not only act as polysulfide reservoirs to alleviate the shuttle effect, but also improve the electrochemical reaction kinetics during the charge–discharge processes. The effect of MoO2–CNF heat treatment on the cycle performance of sulfur/MoO2–CNFs electrodes was examined, and the data showed that MoO2–CNFs calcined at 850 °C delivered optimal performance with an initial capacity of 1095 mAh g−1 and 860 mAh g−1 after 50 cycles. The results demonstrated that sulfur/MoO2–CNF composites display a remarkably high lithium–ion diffusion coefficient, low interfacial resistance and much better electrochemical performance than pristine sulfur cathodes.

Fabrication and properties of core–shell structural nano-TiO2@Fe magnetic photocatalyst for removal of phenol waste water

The core–shell structural nano-TiO2@Fe micro-sized photocatalysts were prepared by a precipitation method followed with a hydrothermal treatment. The results indicate that the sheet-like nano-TiO2 particles are evenly coated on the surface of micro-sized Fe particles to form a core–shell structure with a specific surface area of 31.7xa0m2/g. These composite particles possess combined properties of nano-TiO2 and zero-valent Fe, which make the TiO2@Fe photocatalyst exhibit high photocatalytic activity to remove the phenol pollutant under visible light and have the magnetic property to be easily recycled from treated waters. This magnetically separable photocatalyst can be reused over 20 times with a removal efficiency above 90xa0%.Graphical abstract