A simple, one-pot, "green" synthetic route, based on the "biomineralization" capability of a common commercially available protein, bovine serum albumin (BSA), has been developed for the preparation of highly stable Au nanocrystals (NCs) with red emission and high quantum yield.

The unique structure of MCM‐41 silicates (shown in the picture) has provided for extremely attractive properties—uniform pore sizes greater than 20 Å, surface areas exceeding 1000 m2 g−1, and long‐range ordering of the pores. Recent research in supramolecular‐templated mesoporous materials has led to a wide range of compositions, to uses in a variety of catalytic reactions, and to a better control of bulk morphologies.

This paper presents a systematic study on the role of particle size in pure and doped nanocrystalline TiO2 photocatalysts, which was made possible by a versatile wet-chemical process capable of generating near-agglomeration-free TiO2 with well-controlled particle sizes and dopant dispersion. It is shown that particle size is a crucial factor in the dynamics of the electron/hole recombination process. For TiO2 particles with 6 or 11 nm diameter, Fe3+ dopants were added to inhibit the charge carrier surface recombination. The optimal Fe3+ dopant concentration for different particle sizes was identified, and this concentration was found to decrease with increasing particle size. To assist electron and hole separation in TiO2 with 21 nm diameter, Nb5+ dopants were introduced in combination with minor surface Pt dispersion. These carefully engineered nanocrystalline TiO2 catalysts showed higher reactivities than Degussa P25 TiO2 material in photocatalytic decomposition of chloroform.

Stable to surfactant removal by calcination, Ti‐TMS1 is the first hexagonally packed, mesoporous transition metal oxide. The synthesis of this new material was achieved by a modified sol–gel technique from titanium alkoxides and phosphate surfactants. The large internal surface area, narrow and controllable pore size, thermal stability, and variable oxidation states of the metal give this new material great potential as a catalyst and sorbent.

Quantum dots (QDs) and magnetic nanoparticles (MPs) are of interest for biological imaging, drug targeting, and bioconjugation because of their unique optoelectronic and magnetic properties, respectively. To provide for water solubility and biocompatibility, QDs and MPs were encapsulated within a silica shell using a reverse microemulsion synthesis. The resulting SiO2/MP-QD nanocomposite particles present a unique combination of magnetic and optical properties. Their nonporous silica shell allows them to be surface modified for bioconjugation in various biomedical applications.

The alkoxide sol-gel synthesis of nanostructured TiO 2 has been studied systematically to examine the processing parameters that control crystallite size and phase. Nonagglomerated, ultrafine anatase particles have been generated by hydrothermally treating the sol-gelderived hydrous oxides. The degree of crystallinity and purity of the synthesized materials could affect their structural evolution during heat treatment. It was found that the 10-nm anatase TiO 2 sample derived by hydrothermal processing at 180 °C underwent neither phase change nor significant grain growth up to 800 °C. Nanocrystalline rutile TiO 2 particles have also been attained via hydrothermal treatment in an acidic medium. They possessed an ultrafine rutile grain size and a high surface area, which could not be achieved via phase transformation from thermal treatment of anatase particles.

A simple label-free method for the detection of Hg(2+) ions with high selectivity and sensitivity has been developed by using fluorescent Au NCs in aqueous media. The sensing mechanism was based on the high-affinity metallophilic Hg(2+)-Au(+) interactions, which effectively quenched the fluorescence of Au NCs.

Siliceous mesostructured cellular foams (MCFs) with well-defined ultralarge mesopores and hydrothermally robust frameworks are described. The MCFs are templated by oil-inwater microemulsions and are characterized by small-angle X-ray scattering, nitrogen sorption, transmission electron microscopy, scanning electron microscopy, thermogravimetry, and differential thermal analysis. The MCFs consist of uniform spherical cells measuring 24-42 nm in diameter, possess BET surface areas up to 1000 m 2 /g and porosities of 80-84%, and give, because of their pores with small size distributions, higher-order scattering peaks even in the absence of long-range order. Windows with diameters of 9-22 nm and narrow size distribution interconnect the cells. The pore size can be controlled by adjusting the amount of the organic swelling agent that is added and by varying the aging temperature. Adding ammonium fluoride selectively enlarges the windows by 50-80%. In addition, the windows can be enlarged by postsynthesis treatment in hot water. The MCF materials resemble aerogels, but offer the benefits of a facilitated synthesis in combination with welldefined pore and wall structure, thick walls, and high hydrothermal stability. The open system of large pores give MCFs unique advantages as catalyst supports and separation media for processes involving large molecules, and the high porosities make them of interest for electrical and thermal insulation applications.