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The anatase TiO 2 nanofibers of average diameters 60, 100, and 150 nm were fabricated by controlled electrospinning of a polymeric solution and subsequent sintering of the as-spun fibers. The sintered fibers were polycrystalline and composed of densely packed TiO 2 grains of size ∼12 nm. The rutile phase nucleated at the particle interface of the dense anatase TiO 2 nanofibers at a temperature of <570 °C because of the increased surface stress observed in these nanofibers. X-ray and electron diffraction measurements and analysis of the sintered fibers showed that the lattice strain increased with a decrease in the fiber diameter. The diameter-dependent lattice strain is attributed to the increased surface energy in fibers of lower diameter. The strain most likely originates from interplay of the surface charge and grain boundary effects. The absorption spectra of the fibers showed a red shift with an increase in the fiber diameter, which is attributed to an increase in the surface stress with a decrease in the fiber diameter.

The Eshelby formalism for inclusion/inhomogeneity problems is extended to the nano-scale at which surface/interface effects become important. The interior and exterior Eshelby tensors for a spherical inhomogeneous inclusion with the interface stress effect subjected to an arbitrary uniform eigenstrain embedded in an infinite alien matrix, and the stress concentration tensors for a spherical inhomogeneity subjected to an arbitrary remote uniform stress field are obtained. Unlike their counterparts at the macro-scale, the Eshelby and stress concentration tensors are, in general, not uniform inside the inhomogeneity but are position-dependent. They have the property of radial transverse isotropy. It is also shown that the size-dependence of the Eshelby tensors and the stress concentration tensors follow very simple scaling laws. Finally, the Eshelby formula to calculate the strain energy in the presence of the interface effect is given.

A novel hybrid Nih -CdSe/CdS core/shell quantum dot is a simple and exceptional artificial photocatalyst for H2 production from 2-propanol aqueous solution. Studies on the nature of the artificial photocatalyst and mechanism for H2 production demonstrate that the synthetic strategy is general and the artificial photocatalyst holds promise for light capture, electron transfer, and catalysis at the surface of the Nih -CdSe/CdS core/shell quantum dots, leading to a self-healing system for H2 evolution in harmony.

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A scheme is proposed for predicting the effective conductivities of heterogeneous media containing ellipsoidal inclusions of diverse shapes, spatial distributions, and orientations. This scheme yields explicit expressions for the effective conductivity tensor in terms of three microstructural parameters that characterize the shape, distribution, and orientation of the inclusions. By expanding the effective conductivity tensor in terms of the volume fraction of the inclusions, it is found that the effect of the shape of the distribution ellipsoid on the effective conductivity tensor is of a higher order in the volume fraction than the effect of the shape of the inclusions. The scheme proposed here generalizes the Maxwell formula to heterogeneous media containing multiple inclusions while also taking into account the orientation of the inclusions. Thus, the existing formulas in the literature are special cases of the general formulas given by the present scheme. The predicted effective conductivities of heterogeneous media containing aligned ellipsoidal inclusions, randomly oriented ellipsoidal inclusions, spheroidal inclusions with orientational distributions, and mixtures of cavities and cracks are found to agree well with the experimental results and the results of other schemes.