Weike Zhang

The Preparation and Characterization of ZnS/PMMA Nanocomposites

IIB-VIA group of semiconductor ZnS nanoparticles, which were coated with polymethylmethacrylate (PMMA), are prepared in n-heptane/sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/water microemulsions. Through the reaction of Zn(Ac)2 with the S2– ions released slowly from Na2S, the ZnS nanoparticles were synthesized, then the monomer MMA was dropped into the mixed microemulsion system. After polymerization, the composite was successfully obtained. The initial dosages of all reactants were determined by academic analysis. The products were characterized by UV-vis absorption spectroscopy, X-ray powder diffraction (XRD), and transmission electron microscopy (TEM). The UV/Vis absorption indicates the quantum confinement effect of ZnS nanoparticles. The structure of the composite is characterized by XRD, which reveals that cubic ZnS particles are formed. The TEM image of the sample shows that the diameter of ZnS nanoparticles is approximately 20 nm.

The Direct Decomposition of Nitric Oxide Over Fe/CNOs (CNOs: Carbon Nano Onions)

The decomposition of NO was studied over carbon nano onions (CNOs) supported Fe catalyst made in a facility of spinning disc process (SDP). At the temperature of 500°C, 83% NO was decomposed to N2 with 93% of selectivity (N2 formation rate: 3.44 µmol N2·s–1·gcatalyst–1). The rest are the by-products of NO2 and N2O. X-ray diffraction study demonstrated that the iron carbide was generated in the catalyst. Thermogravimetric analysis indicated that CNOs were stable below 600°C under air atmosphere. In situ diffuse reflectance infrared Fourier transformation spectroscopy study detected the NO2 and N2O2 species during NO adsorption.

Catalytic NO Decomposition Over Carbon Nanotubes Supported Cu–Mn

The decomposition of nitric oxide (NO) was studied over carbon nanotubes (CNTs) supported Cu–Mn catalyst. CNTs were home-made by cracking of methane over the LaNiO3 catalyst. At the temperature of 500°C, 71.8% NO was decomposed into N2 (71% selectivity) with the by-products of NO2 and N2O (29% selectivity in total). X-ray photoelectron spectroscopy investigation found the existence of Mn3+ and Cu+ in Cu–Mn/CNTs, respectively. The NO temperature programmed desorption (NO-TPD) study indicated that the adsorption of NO resulted in the desorption of NO, NO2, N2O, N2, O2, and CO2. The apparent activation energy for NO decomposition over Cu–Mn/CNTs is 23 kcal/mol.

Methane Catalytic Cracking to Make Hydrogen and Graphitic Nano Carbons (Nanotubes, Microfibers, Microballs, Onions) with Zero Emission

Methane was catalytically decomposed to hydrogen and highly graphitic carbon nanotubes, microfibers, microballs, and nano onions. Over Mo x –Ni(Fe,Co) y –MgO z , single-walled carbon nanotubes (SWNTs) and thin-walled carbon nanotubes (TWNTs) were produced; over Ni/Y, individually separated SWNTs were generated; over La2NiO4, multiwalled carbon nanotubes (MWNTs) were made. Over Ni/MCM-41, with the addition of benzene, the carbon microballs (CMBs) were produced. Over Fe–Cr alloy and LaNi0.9Co0.1O3, the carbon nano onions (CNOs) and carbon microfibers (CMFs) were produced, respectively. The methane conversion efficiency and carbon growth rate followed the order: CNOs > CMBs > CMFs > MWNTs > TWNTs > SWNTs.

Preparation and Characterization of Ag2S/PMMA Nanocomposites by Microemulsion

Ag2S nanoparticles in polymethyl methacrylate (PMMA) are prepared in n-heptane/sodium bis(2-ethylhexyl)sulfosuccinate/water microemulsions. The Ag2S nanoparticles dispersed in the polymer are characterized by FT-IR spectrum, UV–Vis absorption spectroscopy, transmission electron microscopy (TEM), and X-ray powder diffraction (XRD). The FT-IR spectrum shows that the composite has the characteristic bands of nano-Ag2S and pure PMMA. The TEM photograph of the sample shows that the Ag2S nanoparticles are elliptical. The phase structure of the composite is characterized by XRD, which reveals that Ag2S particles are formed. The UV–Vis absorption recorded at various times indicates an initial rapid formation of the nanoparticles and the quantum confinement effect of Ag2S nanoparticles.

The preparation of PbS/polymethylmethacrylate (PMMA) nanocomposites by microemulsion

ABSTRACT In this work, through a novel route, nano-PbS/polymethylmethacrylate (PMMA) composites were successfully synthesized in microemulsion solutions containing sodium bis(2-ethylhexyl) sulfosuccinate, n-heptane, and water. Transmission electron microscopy was used to investigate the morphology of the synthesized products. The structures of nano-PbS/PMMA were characterized by X-ray powder diffraction, and the luminescent properties of resultant hybrid materials were characterized by UV757CRT spectrophotometer and luminescence spectrometer.

Synthesis and Characterization of Rhodamine B Embedded in MCM-41

Rhodamine B, a familiar organic dye, was embedded in mesoporous silica (MCM-41) that had been modified by (3-aminopropyl) triethoxysilane (APTES) through chemical bonding method. The materials were investigated by small angle X-ray diffraction (XRD), transmission electron microcopy (TEM), fourier transform infrared spectrometry (FT-IR), and photoluminescence spectroscopy (PL). The structure of the composites was characterized by XRD, which reveals that the mesoporous structure is maintained and the functional groups have been introduced into the mesostructure. The TEM photograph of the sample future shows that the ordered mesoporous structure is maintained after grafting. The FT-IR spectra improve that RhB has been successfully introduced into the mesoporous silica. The PL spectra of the product indicate that the emission spectrum shift to lower wavelength after grafting.

The Production of Carbon Nano-Onions and Wheat Stalk Nano-Chains over Stainless Steel Supported La0.95Mg0.05Ni0.8Co0.2O3 Catalyst

Over the 316 stainless steel mesh supported La0.95Mg0.05Ni0.8 Co0.2O3 perovskite structured catalyst, undiluted methane was cracked into hydrogen and highly graphitic carbon nano-onions (CNOs) and wheat stalk chains, the former was first produced in cheaper and simpler way and the later was first discovered. The Fe-Cr nano-alloy was responsible for the formation of the CNOs while the Ni or Ni-Fe nano-alloy was for the formation of carbon nano-wheat stalk chains. This process realized the ultimate ideal goal for the natural gas utilization: zero emission, clean hydrogen production, zero waste, and highly valuable carbon recycling. Moreover, the capacitances of the CNOs were evaluated by the cyclic voltammetry at different scan rates. The result indicated the capacitance of the CNOs was higher than that of Vulcan XC-72 carbon black, showing their promising applications in supercapacitors.