Liuyang Bai

Synthesis of uniform octahedral tungsten trioxide by RF induction thermal plasma and its application in gas sensing

Well-defined uniform octahedral WO3 are prepared via a simple one-step thermal plasma technique. The detailed structures of the synthesized materials are characterized by XRD, EDX, FESEM, SAED and HRTEM. Each octahedron is nearly perfect with a highly symmetric, regular shape containing 8 facets, 6 vertices, and 12 edges, which exhibit sharp edges and corners as well as smooth surfaces. Processing parameters dependent experiments are performed to control its shape and size distribution. The regular octahedral WO3 shows good sensing properties to benzene gas, which might mainly be due to its highly exposed {111} faces and the regular octahedral shape.

Formation of cubic Cu mesocrystals by a solvothermal reaction

Cubic Cu mesocrystals were prepared via a facile solvothermal reaction in a mixed solvent of glycerol–water. The microstructure of synthesized mesocrystals can be successfully controlled by adjusting the volume ratio of glycerol/water. The evolution of these cubic Cu mesocrystals was investigated and the mechanism was discussed. The oriented attachment process controls the initial stage in the formation of scabbled cubic Cu mesocrystals and then Ostwald ripening process contributes to the formation of the final Cu mesocrystals by shearing the scabbled mesocrystals. The influences of reaction temperature and NaOH concentration on the morphology of the synthesized mesocrystals were also investigated. Isotropic conductive adhesives (ICA), filled with cubic Cu mesocrystals, exhibit a low bulk resistivity, of about 5.21 × 10−4 Ω cm.

Synthesis of Nickel Powders: From Spheres to Monodispersed Clusters

Well dispersed nickel powders with uniform size were synthesized using hydrazine hydrate as reducing reagent, with no surfactant introduced. The morphology of the products could be controlled from smooth spheres to flowerlike clusters by simply choosing solvent and adjusting the molar ratio of NaOH/Ni or N2H4/Ni. A two-step reduction process was proposed for the formation mechanism based on the experimental results. The crystal phase of the as-prepared sample was characterized by XRD. The morphology and microstructure were inspected with FESEM. The magnetic properties were recorded using VSM. The novel flowerlike clusters exhibit unique magnetic properties.