Caixia Song

Formation of silver nanoshells on latex spheres

Silver nanoshells on styrene–acrylic acid copolymer latex spheres (PSA) were deposited by an in situ chemical reduction method, ageing a colloid solution at 85 °C containing PSA latex, AgNO3, urotropine, and poly-(vinylpyrrolidone). SEM and TEM observations showed that the silver nanoshells were made of closely packed silver nanoparticles of different sizes and morphologies. UV–visible absorption spectra were recorded to investigate their optical properties.

Facile synthesis of CeO2 decorated Ni(OH)2 hierarchical composites for enhanced electrocatalytic sensing of H2O2

CeO2–Ni(OH)2 composites with hierarchical structures were synthesized via a facile one-pot hydrothermal method, which were constructed with Ni(OH)2 nanosheets decorated with in situ formed CeO2 nanoparticles on their surface. The composites were characterized by XRD, SEM, HRTEM, XPS, Raman spectroscopy, and electrochemical techniques. The results of nitrogen adsorption–desorption, electrochemical impedance spectroscopy, and amperometry demonstrated that CeO2 and Ni(OH)2 components of CeO2–Ni(OH)2 hierarchical architectures showed a synergistic contribution on the improvement of electrochemical activity toward H2O2. The oxidation current was linearly related to the H2O2 concentration from 0.5 μM to 1.2 mM. The sensor showed a high sensitivity of 4.5 μA μM−1 cm−2 with a lower detection limit of 0.035 μM (S/N = 3). Moreover, the sensor showed good selectivity, reproducibility and stability. These results demonstrated the feasibility of the synthetic strategy and the potential of the composites as a promising candidate for H2O2 sensing.

Synthesis of Mono-Dispersed Mg(OH)2 Nanoflakelets

Mono-dispersed Mg(OH)2 nanoflakelets have been prepared with the assistant of 4-(p-nitrophenylazo)resorcinol. The samples were characterized using XRD, TEM, and ED. Electron diffraction analysis showed that single crystalline nanoflakelets were obtained in hydrothermal process, and porous Mg(OH)2 nanosheets were prepared at lower temperature. Nitrogen adsorption isotherms show that the surface area of Mg(OH)2 nanosheets is 129 m2/g. Possible growth mechanism of the nanoflakelets is discussed.

Surfactant‐Assisted Synthesis of Cube‐Shaped PbTe and PbSe Nanocrystals

Uniform cubic‐shaped PbTe and PbSe nanocrystals have been synthesized through the surfactant‐assisted hydrothermal reaction between Pb(NO3)2 and Te or Se powders with hydrazine hydrate as reducing reagent. The products were characterized by powder x‐ray diffraction (XRD) and transmission electron microscopy (TEM). It was found that the shapes of nanocubes are well controlled by using ethylenediaminetetraacetic acid as chelating reagent and in the presence of poly(vinyl‐pyrrolidone).

Crystal-Phase- and Morphology-Controlled Synthesis of Fe2O3 Nanomaterials

The crystal phase and morphology of MoO3 materials were precisely tuned under suitable synthetic conditions and mutual transformation of h-MoO3 and α-MoO3 was achieved via a facile hydrothermal method for the first time. The h-MoO3 microrods with a diameter of 0.5–1.6 μm and length of 2.2–6.1 μm were fabricated with the assistance of NaNO3 using α-MoO3 particles as the precursor. The transformation of h-MoO3 microrods to α-MoO3 nanobelts with a diameter of 150–430 nm and length of 2.1–14.5 μm occurred through hydrothermal techniques at higher temperature. Systematic studies of synthetic parameters revealed that the hexagonal h-MoO3 microrods formed at higher concentration of NaNO3, while h-MoO3 microrods vanished at higher temperature with prolonged time and α-MoO3 nanobelts were exclusively produced. The h-MoO3 microrods exhibited higher catalytic activity in photo-degradation of methylene blue than the α-MoO3 nanobelts. This is ascribed to the weaker fluorescence and reduced bandgap energy of the h-MoO3 microrods than those of the α-MoO3 nanobelts.

Design, controlled synthesis, and properties of 2D CeO2/NiO heterostructure assemblies

Synthetic protocols to generate well-integrated frameworks of known composition are important for the rational design of advanced materials. 3D CeO2/NiO hierarchical assemblies were designed and constructed with 2D CeO2/NiO heterostructures as building blocks consisting of NiO nanosheets wrapped with CeO2 ultrathin nanosheets on the surfaces. The growth process of the 2D CeO2/NiO heterostructure nanosheets and the 3D assemblies was described based on a domain-matching growth process. The CeO2/NiO assemblies exhibited superior catalytic properties for CO oxidation. A model of the structure–property relationships based on surface and interface structures is discussed.

General Route to Synthesize Monodisperse Oxide (Hydroxide) Nanoparticles

Mono-dispersed oxide and hydroxide nanoparticles have been synthesized through the solvothermal process in alcohol-water mixtures. The products were characterized by powder x-ray diffraction (XRD) and scanning electron microscopy (SEM). Plate-like nanoparticles are obtained for Bi2O2.33, Fe2O3, and Cd(OH)2, and spherical nanoparticles are obtained for SnO2. The growth mechanism for the mono-dispersed nanoparticles has been preliminarily discussed.