Jingxing Chen

Preparation and properties of antibacterial TiO2@C/Ag core?shell composite

Abstract An environment-friendly hydrothermal method was used to prepare TiO2@C core–shell composite using TiO2 as core and sucrose as carbon source. TiO2@C served as a support for the immobilization of Ag by impregnation in silver nitrate aqueous solution. The chemical structures and morphologies of TiO2@C and TiO2@C/Ag composite were characterized by x-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, energy dispersive x-ray spectroscopy and Brunauer–Emmett–Teller (BET) analysis. The antibacterial properties of the TiO2@C/Ag core–shell composite against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were examined by the viable cell counting method. The results indicate that silver supported on the surface of TiO2@C shows excellent antibacterial activity.

Synthesis of ZnO@CNTs From Anhydrous Zinc Acetate via Thermal Decomposition

The ZnO@CNTs has been prepared via a thermal decomposition route. The spectra of X-ray powder diffraction (XRD) prove that as-prepared ZnO is primitive hexagonal phase and CNTs with an interlayer distance of 0.34 nm is low graphitized carbon in this research. The diameter and length of ZnO@CNTs are 150–200nm and 1.5–2µm, respectively. The vibration on 1625cm –1 , 1540cm –1 and 1380 cm –1 shows that the surface of ZnO@CNTs have great functional groups. Advance materials prepared via thermal decomposition techniques attract broad research interests [1-3]. In appropriate temperature and pressure, the size and structure of materials are controlled through the synthesis condition. Cha and co-workers have revealed that the thermal decomposition is economical and easy method to synthesis some monodispersed nanocrystal [3]. Metal oxide and carbon materials have been widely fabricated via thermal decomposition [2-9]. Carbon nanotubes (CNTs) with unique physical and chemical properties have broad applications in the field of many high-tech, especially assembled other nano-materials on the surface of CNTs to achieve the function of the CNTs. At the same time, ZnO has received widespread attention for its excellent performance in electronics, optics, photonics systems. So many scientists have considerable paid attention to assemble ZnO to carbon nanotubes to obtain excellent optics, catalyse, anti-bacterial properties. The ZnO@CNTs materials have been fabricated using many methods, such as electrostatic coordination approach [10], plasmaassisted sputtering technique [11], chemical vapor deposition[12,13] and so on. However, to the best of our knowledge, there is no report on the preparation of carbon nanotubes coating ZnO composite. In this study, the ZnO@CNTs has been prepared via thermal decomposition anhydrous zinc acetate without any catalyst and toxic reagents. The surface functional groups of CNTs have been investigated.

Synthesis of Hollow-Cone-Like Carbon and Its Application as Support Material for Fuel Cells

A simple solvothermal method is employed to prepare a hollow conelike carbon (HCC) with an open hemline. The HCC was characterized by transmission electron microscopy, X-ray diffraction, N 2 sorption, Raman spectroscopy, and electrochemical techniques. Electrochemical characterizations show that activated HCC has improved corrosion resistance over Vulcan XC-72 carbon black. Platinum supported on this activated HCC was prepared and evaluated for methanol oxidation in acidic media for the first time. Pt/HCC electrocatalyst exhibits higher activity for methanol oxidation compared to Pt/C at the same Pt loading. It is believed that open, hollow HCC acts as a structure unit and facilitates the mass diffusion and transfer inside the carbon cones due to larger orifices. The unique structure and higher corrosion resistance makes the Pt/HCC electrocatalyst a potential candidate to be used in direct methanol fuel cells.