Jin Cheng

Preparation of carbon nanotubes by ethanol catalytic combustion technique using nickel salt as catalyst precursor

A simple growth technique of carbon nanotubes (CNTs) by combustion of ethanol was developed. In the experiment, copper plate was employed as substrate, nickel nitrate (Ni(NO3)2) and nickel chloride (NiCl2) as catalyst precursor, and ethanol as carbon source. The cleaned copper substrate was dipped into catalyst precursor solution for mounting catalyst precursor particles. The dip-coated substrate was then placed into ethanol flame for about 10 min after drying. The black wool-like production grown on copper plate was obtained. This route is called an ethanol catalytic combustion(ECC) process. The black powders were characterized by means of scanning electron microscopy(SEM), transmission electron microscopy(TEM), energy dispersive X-ray spectrometer(EDS) and Raman spectroscopy. The results show that the techique is much simpler and more economical to meet the future broader applications.

Synthesis of bamboo-like carbon nanotubes by ethanol catalytic combustion technique

Bamboo-like carbon nanotubes were synthesized by ethanol catalytic combustion (ECC) technique with combustion method. Copper plate was employed as substrate, ethanol as carbon source, and iron chloride as catalyst precursor. The as-grown black powder was characterized by means of scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that the thinner bamboo-like carbon nanotubes have a relatively good structure that the compartment layers are more regular, while the thicker carbon nanotubes have a relatively irregular bamboo-like structure; the proposed method is simple to synthesize bamboo-like carbon nanotubes and has some advantages, such as flexible synthesis conditions, simple setup, and environment-friendly.

Synthesis of Y-junction carbon nanofibres by ethanol catalytic combustion technique

Y-shaped structure was synthesized by ethanol catalytic combustion(ECC) technique on the copper plate substrate, without directly seeding catalyst into the flame. The as-grown Y-junction carbon nanofibres were investigated by transmission electron microscopy (TEM). The very common laboratory ethanol burner was used for synthesizing carbon nanofibres. Two kinds of the catalyst precursor, which are iron nitrate (Fe(NO3)3) and nickel nitrate (Ni(NO3)2), were respectively employed to assist the formation of Y-junction carbon nanofibres. TEM analysis confirm the formation of Y-junction in the coiled and noncoiled carbon nanofibres. The type of the catalyst is found to be crucial to grow different Y-junction carbon nanofibres. Different Y-shaped structure may possess different mechanical and electronic properties. These three-terminal nanofibres provide the nanoelectronics community with a novel material for the development of molecular-scale electronic devices.

The Effect of the Shape of the Catalyst on the Morphologies of the Carbon Fibers

Catalytic grown carbon fibers have been synthesized by the decomposition of carbon‐containing gases over copper substrate. Metal nitrate was used as the catalyst precursor for the catalyst necessary for the carbon fiber growth. The structural characteristics of the carbon product were assessed from the scanning electron microscopy (SEM). SEM studies have revealed that catalysts have a tremendous impact on the control of the growth characteristics of carbon fibers, and there is a relation between the morphology of the carbon fibers and that of the catalyst.

Effects of catalyst precursors on carbon nanowires by using ethanol catalytic combustion technique

Iron nitrate, nickel nitrate and cobalt nitrate were used as catalyst precursors to study their effects on carbon nanowires synthesized by ethanol catalytic combustion (ECC) process. The as-grown carbon nanowires were characterized by means of scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that relatively uniform nanowires will be formed when the catalyst precursor is iron nitrate; while helical structure or disordered structure will be formed when the catalyst precursor is nickel nitrate or cobalt nitrate.

Preparation of PZT ferroelectric thin films by electrochemical reduction

In this paper, we report the growth of lead zirconate titanate (PZT) ferroelectric thin films, formed by means of the electrochemical reduction. In our experiment, the electrolyte was prepared by lead nitrate (Pb(NO3)2), zirconium oxide chloride (ZrOCl2-8H2O) and titanium chloride (TiCl3) solution. A graphite plate with 1 cm of width was employed as the anode, and a stainless steel plate was employed as both cathode and substrate. The controlled current that was supplied by a DC power supply passed through the electrolyte to deoxidize PZT precursor films on the surface of the stainless steel at room temperature. The results indicate that the atomic ratio of compositions in the film can be controlled by controlling the molar concentration of electrolytic solution, current density and reaction time. The perovskite PZT thin films can be obtained when the precursor films are heated to a certain temperature for sintering.

Influence of the shape and size of catalyst on the morphology of carbon sub-microfibers

The investigation of the relation of catalyst particles with resultant carbon deposits has been carried out. In this paper, the influences of catalyst particles on the morphology of carbon fibers are studied. Carbon fibers have been synthesized by the decomposition of methanol/ethanol over copper substrate via catalytic combustion technique and chemical vapor deposition method. The structural characteristics of the carbon product were assessed from the scanning electron microscopy. In situ scanning electron microscopy showed that the size and the shape of the catalyst particles can influence the morphology of the resultant carbon fibers.

Synthesis of carbon nanofibers by ethanol catalytic combustion

The effects of position of substrates in flames, preparation time, stability of flames and catalyst precursors on carbon nano fibers are investigated in ethanol catalytic combustion. For investigating the effects of these influence factors on carbon nano fibers, several sets of controlled experiments are performed, such as different position of substrates, different preparation time, stable and unstable flames, different catalyst precursors. In our experiments, the catalyst precursors are iron nitrate, cobalt nitrate, nickel nitrate, and iron chloride, cobalt chloride, nickel chloride. The as-synthesized products are characterized by scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. Our results show that the optimal position of substrates in flames is more than 1 cm and less than 2.5 cm for massive yield, the optimal preparation time is more than 5 min and less than 30 min for massive yield, stable flames would be tent to synthesize carbon nano fibers with single-type morphology and could improve the graphitization of carbon nano fibers, and the catalyst precursors have obvious effects on carbon nanofibers.

Multi-directionally grown ribbon-like carbon fibers

Here, a simple and low cost catalytic combustion method was employed for preparation of ribbon-like carbon fibers. A lot of multi-directionally grown ribbon-like carbon fibers were obtained. In our experiment, methanol was used as the carbon source and the nickel nitrate as the catalyst precursor. The copper plate was used as the substrate. M. M. Wilson et al. also adopted flame method, but their setup is complex. From the view of realizable application, our method is more adaptive. This study has significances for fundamental investigation and has a promising of industrial application.

Preparation and characterization of SiO 2 nano-rods by CVD method

A simple method is presented for the preparation of silica nano-rods. The silica nano-rods with a diameter of about 200 nm with smooth surface were synthesized by chemical vapor deposition method at 1300square. The as-synthesized samples were characterized by means of scanning electron microscopy, energy dispersive x-ray, and transmission electron microscopy. The results show that synthesized silica nano-rods have a uniform size, well-defined shape, and smooth surface. However, the morphologies and microstructures of silica nano-rods are affected by synthesis conditions, such as the synthesis temperature and the vapor concentration of the SiOx. On the basis of these experimental results, a possible growth mechanism of silica nano-rods in this process is proposed.