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Highly dispersed nanometer-sized a-Fe 2 O 3 (hematite) and c-Fe 2 O 3 (maghemite) iron oxide particles were synthesized by the combustion method. Ferric nitrate was used as a precursor. Xray diffractometer study revealed the phase purity of aand c-Fe 2 O 3 . Both the products were characterized using field emission scanning electron microscope and transmission electron microscope for particle size and morphology. Necked structure particle morphology was observed for the first time in both the iron oxides. The particle size was observed in the range of 25-55 nm. Photodecomposition of H 2 S for hydrogen generation was performed using aand c-Fe 2 O 3 . Good photocatalytic activity was obtained using aand c-Fe 2 O 3 as photocatalysts under visible light irradiation. P. Gouma-contributing editor

The simple, template-free, low-temperature, large-scale synthesis of nanostructured CdS with the hexagonal wurtzite phase from bulk cadmium oxide under solid-phase conditions is demonstrated for the first time. The novel approach involves the homogenization of cadmium oxide (CdO) and thiourea in various stoichiometric ratios at moderate temperature. Among the different molar ratios of CdO and thiourea studied, the CdO/NH(2) CSNH(2) molar ratio of 1:2 is found to be the best to obtain highly pure CdS. The obtained CdS nanostructures exhibit excellent cubic morphology and high specific surface area with a particle size in the range of 5-7 nm. The bandgap of the nanostructured CdS is in the range of 2.42 to 2.46 eV due to its nanocrystalline nature. In photoluminescence studies, emission is observed at 520.34 and 536.42 nm, which is characteristic of the greenish-yellow region of the visible spectrum. Considering the bandgap of the CdS is within the visible region, the photocatalytic activity for H(2) generation and organic dye degradation are performed under visible-light irradiation. The maximum H(2) evolution of 2945 μmol h(-1) is obtained using nanostructured CdS prepared in the 1:2 ratio, which is three times higher than that of bulk CdS (1010 μmol h(-1) ). CdS synthesized using the 1:2 molar ratio shows maximum methylene blue degradation (87.5%) over a period of 60 min, which is approximately four times higher than that of bulk CdS (22%). This amazing performance of the material is due to its nanocrystalline nature and the high surface area of the CdS. The proposed simple methodology is believed to be a significant breakthrough in the field of nanotechnology, and the method can be further generalized as a rational preparation scheme for the large-scale synthesis of various other nanostructured metal sulfides.

Polymorphous low-grade adenocarcinoma (PLGA) is difficult to diagnose due to its indolent clinical presentation and due to its morphological diversity that includes several microscopic patterns. Distinguishing it from high-grade tumors of salivary gland is important, as the management and prognosis of this tumor differ. We report a considerably rare case of PLGA in retromolar area highlighting various diagnostic challenges caused by the overlap of clinical and microscopic features between PLGA and other salivary gland neoplasms and discuss current management strategies.

Spherically shaped plasmonic Au nanoparticles (NPs) of size 10 nm (±4 nm) have been decorated on TiO2 NPs for the synthesis of Au@TiO2 composites via an aqueous sol–gel method.

The synthesis of orthorhombic nitrogen-doped niobium oxide (NbON) nanostructures was performed and a photocatalytic study carried out in their use in the conversion of toxic HS and water into hydrogen under UV-Visible light. Nanostructured orthorhombic NbON was synthesized by a simple solid-state combustion reaction (SSCR). The nanostructural features of NbON were examined by FESEM and HRTEM, which showed they had a porous chain-like structure, with chains interlocked with each other and with nanoparticles sized less than 10 nm. Diffuse reflectance spectra depicted their extended absorbance in the visible region with a band gap of 2.4 eV. The substitution of nitrogen in place of oxygen atoms as well as Nb-N bond formation were confirmed by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. A computational study (DFT) of NbON was also performed for investigation and conformation of the crystal and electronic structure. N-Substitution clearly showed a narrowing of the band gap due to N 2p bands cascading above the O 2p band. Considering the band gap in the visible region, NbON exhibited enhanced photocatalytic activity toward hydrogen evolution (3010 μmol h g) for water splitting and (9358 μmol h g) for HS splitting under visible light. The enhanced photocatalytic activity of NbON was attributed to its extended absorbance in the visible region due to its electronic structure being modified upon doping, which in turn generates more electron-hole pairs, which are responsible for higher H generation. More significantly, the mesoporous nanostructure accelerated the supression of electron and hole recombination, which also contributed to the enhancement of its activity.

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We have demonstrated a template-free large-scale synthesis of nanostructured Cd(x)Zn(1-x)S by a simple and a low-temperature solid-state method. Cadmium oxide, zinc oxide, and thiourea in various concentration ratios are homogenized at moderate temperature to obtain nanostructured Cd(x)Zn(1-x)S. We have also demonstrated that phase purity of the sample can be controlled with a simple adjustment of the amount of Zn content and nanocrystalline Cd(x)Zn(1-x)S(x = 0.5 and 0.9) of the hexagonal phase with 6-8 nm sized and 4-5 nm sized Cd(0.1)Zn(0.9)S of cubic phase can be easily obtained using this simple approach. UV-vis and PL spectrum indicate that the optical properties of as synthesized nanostructures can also be modulated by tuning their compositions. Considering the band gap of the nanostructured Cd(x)Zn(1-x)S well within the visible region, the photocatalytic activity for H2 generation using H2S and methylene blue dye degradation is performed under visible-light irradiation. The maximum H2 evolution of 8320 μmol h(-1)g(-1) is obtained using nanostructured Cd(0.1)Zn(0.9)S, which is four times higher than that of bulk CdS (2020 μmol h(-1) g(-1)) and the reported nanostructured CdS (5890 μmol h(-1)g(-1)). As synthesized Cd(0.9)Zn(0.1)S shows 2-fold enhancement in degradation of methylene blue as compared to the bulk CdS. It is noteworthy that the synthesis method adapted provides an easy, inexpensive, and pollution-free way to synthesize very tiny nanoparticles of Cd(x)Zn(1-x)S with a tunnable band structure on a large scale, which is quite difficult to obtain by other methods. More significantly, environmental benign enhanced H2 production from hazardous H2S using Cd(x)Zn(1-x)S is demonstrated for the first time.