To reveal the electron and phonon transport mechanism in bismuth nanowire (BiNW), the electronic structure, the lattice dynamics, and the thermoelectric properties of bismuth bulk (BiB) and BiNW were investigated in this paper through first-principles calculation and the Boltzmann transport theory. The results suggest that BiNW possesses an increased electrical conductivity and Seebeck coefficient, while its thermal conductivity, especially phonon thermal conductivity, is reduced significantly as compared to BiB. As a consequence, a largely enhanced figure of merit (ZT) at 300 K of 2.73 is achieved for BiNW. The enhancement in electrical conductivity and Seebeck coefficient of BiNW is originated from its high density of states and large effective mass of carriers. Such significant suppression in phonon thermal conductivity of BiNW is ascribed to the reduced phonon vibration frequency, the decreased phonon density of states, and the shortened mean free path of phonons. So BiNW should be viewed as an excellent candidate for a thermoelectric material with a high figure of merit. Moreover, we have provided a complete understanding on the relationship between the electronic structure, the dynamics, and the thermoelectric properties of BiNW.

Antimony doped tin oxide (ATO) is an ideal material for thermal insulation. To obtain the stable performance of ATO nanodispersions and measure the transparent and thermal insulation properties of the ATO coatings, we investigated how a dispersant and sand milling affect the stability of ATO dispersion, which has come to the results that adding an appropriate dispersant and sand milling for 2.0 h were beneficial to the ATO dispersion. We characterized the morphology, nanostructure, particle size distribution, zeta potential, and optical properties of the ATO dispersions by a transmission electron microscope (TEM), a laser particle size analyzer, and a spectrometer. The results show that the average particle size of the dispersions is about 50 nm and their absolute values of all zeta potentials are more than 40 mV. We coated the thermal insulation water-based coatings on quartz glasses by spin coating method, the effect of thermal insulation is evident with the increase of the ATO content, and there exists approximately 10 °C difference between the ATO sample and blank sample with the condition for maintaining high transmittance of visual light.

Structural distortions at the nanoscale are delicately linked with many exotic properties for ferroic thin films. Based on advanced aberration corrected scanning transmission electron microscopy, we observe BiFeO3 thin films with variant tensile strain states and demonstrate at an atomic scale the interplay of intrinsic spontaneous structural distortions with external constraints. Structural parameters (the rhombohedral distortion and domain wall shear distortion) under zero (BiFeO3/GdScO3) and 1.5% (BiFeO3/PrScO3) lateral strain states are quantitatively analyzed which are suppressed within a few unit cells near the film/substrate interfaces. In particular, an interfacial layer with asymmetrical lattice distortions (enhanced and reduced out-of-plane lattice spacing) on the two sides of 109° domain wall is resolved. These structural distortions near the film/substrate interface in ferroic thin films reveal intense tanglement of intrinsic distortions of BiFeO3 with external boundary conditions, which could provide new insights for the development of nanoscale ferroelectric devices.

We have investigated theoretically the role of Cr-d states in the electronic and optical properties of the CdCr2X4 (X = S, Se) normal ferromagnetic spinels using the framework of an all-electron full-potential linearized augmented plane wave method. The calculations are performed using Coulomb corrected Perdew–Burke–Ernzerhof (PBE+U) and Tran–Blaha modified-Becke–Johnson (TB-mBJ) approximations with the adding of spin–orbit coupling in both schemes. The lattice parameters have been optimized and are in agreement with the existing experimental values. We found band gap values 1.606 eV and 0.972 eV of CdCr2X4 (X = S, Se), respectively, using the TB-mBJ scheme. Analysis of the site and momentum projected densities shows that the larger splitting of Cr-d states is responsible for the larger band gap by the use of the TB-mBJ scheme. Optical properties along the directions of lattice constants are studied on the basis of band to band transitions. We found the isotropic nature of the optical properties. Reflectivity stays low up to 1.6 eV, consistent with the energy gaps obtained using the TB-mBJ scheme in both the compounds. The refractive index, n(ω), and the extinction coefficient, k(ω), are also studied by the PBE and the TB-mBJ schemes.

A series CeO2/Al2O3 catalysts was modified with rare earth element (La, Nd, Sm, Gd, and Tm) using extrusion method. The catalytic activities of the obtained catalysts were measured for the selective catalytic reduction (SCR) of NO with NH3 to screen suitable addition of rare earth element. These samples were characterized by X-ray diffraction (XRD), N2 adsorption (N2-BET), NH3 temperature-programmed desorption analyses (NH3-TPD), H2 temperature-programmed reduction (H2-TPR), Raman spectra, pyridine adsorption Fourier-transform infrared (Py-IR) and X-ray photoelectron spectroscopy (XPS), respectively. Results showed that the CeO2/Al2O3 exhibited excellent performance in resisting reactant poisoning caused by vapor and sulfur and the highest catalytic activity (98.35%) at 360 °C when the added Tm/Ce molar ratio is 0.10. The surface acidity of CeO2/Al2O3 catalyst would be enhanced with the addition of rare earth ions. Consequently, rare earth ion was beneficial to catalytic activity at low temperatures and corresponded to similar law. Analysis revealed that the higher number of acid sites and the more Ce3+ were conductive to obtain the excellent NH3-SCR activity.