Self-assembly of CdSe 3D urchins and their photocatalytic response.

Photocatalysis is found to be one of the best suited processes that respond to the purification of water systems and the semiconductor nanomaterials are learned to be incredible materials which carry out the photocatalytic process as they readily decompose the pollutants effectively. In this present work, CdSe nanoparticles belonging to II-VI group semiconductor compounds were synthesized using a facile hydrothermal process with different precursor concentrations and were analysed for various characterization studies such as X-ray diffraction (XRD), Transmission electron microscopy (TEM), UV-vis absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR) and Photoluminescence (PL) studies. The XRD study of the synthesized CdSe nanostructures revealed that the average crystallite size was ranging from 18.5 nm to 24 nm pointing out the increase in size with increase in molar concentrations. The morphological structure of synthesized CdSe samples exhibited urchin-like structure for a lower concentration with several rod-like projections appearing in diverse directions. These CdSe nano-urchins synthesized with lower concentrations are found suitable to carry out the process of photocatalytic activity. The process was carried out under visible light radiation for 180 min with aqueous solution of methylene blue (MB) as the ideal toxin to be degraded. The attained degradation efficiency was nearly 80% clearly displaying that the synthesized samples are good photocatalysts. By tuning the bandgap, through the optimization of the precursor concentrations, greater efficiency can be achieved in future.

Photocatalytic degradation effect of CdSe nanoparticles for textile wastewater effluents at low cost and proves to be efficient method.

Semiconductor nanoparticles and nanocrystals have a great impact due to its contribution in the diverse fields including electronics, solar energy, biological imaging, and photonics. Among these semiconductor nanoparticles, cadmium selenide of II-VI group binary semiconductor nanoparticles were synthesized using solvothermal process for the different reaction temperatures. The XRD pattern of the synthesized samples confirms the crystalline nature of the samples and showed increase in its crystallite size with rise in temperature. The morphology of the samples was analysed with TEM images and found that the nanoparticles synthesized at different temperatures were varied in size and shape indicating the increase in the size of the particles with the raise in temperature. The optical properties of the samples pointed out that they exhibit a blue shift owing to quantum confinement. Photocatalytic activity was carried out for the synthesized samples under visible light radiation using methylene blue (MB) as a model pollutant and it proved to be a good photocatalyst achieving the efficiency of 75% which is promising for future application with good optimization. The efficiency could be increased when these semiconductor CdSe nanoparticles are doped with metal particles due to an increase in the absorption edge wavelength and a decrease in bandgap energy were reported in detail.

Crystal structures of two stilbazole derivatives: bis-{(E)-4-[4-(di-ethyl-amino)-styr-yl]-1-methyl-pyridin-1-ium} tetra-iodido-cadmium(II) and (E)-4-[4-(di-ethyl-amino)-styr-yl]-1-methyl-pyridin-1-ium 4-meth-oxy-benzene-sulfonate monohydrate.

The title mol-ecular salts, (C18H23N2)2[CdI4], (I), and C18H23N2 +·C7H7O4S-·H2O, (II), are stilbazole, or 4-styryl-pyridine, derivatives. The cation, (E)-4-[4-(di-ethyl-amino)-styr-yl]-1-methyl-pyridin-1-ium, has a methyl group attached to pyridine ring and a diethyl amine group attached to the benzene ring. The asymmetric unit of salt (I), comprises one cationic mol-ecule and half a CdI4 dianion. The Cd atom is situated on a twofold rotation axis and has a slightly distorted tetra-hedral coordination sphere. In (II), the anion consists of a 4-meth-oxy-benzene-sulfonate and it crystallizes as a monohydrate. In both salts, the cations adopt an E configuration with respect to the C=C bond and the pyridine and benzene rings are inclined to each other by 10.7 (4)° in (I) and 4.6 (2)° in (II). In the crystals of both salts, the packing is consolidated by offset π-π stacking inter-actions involving the pyridinium and benzene rings, with centroid-centroid distances of 3.627 (4) Šin (I) and 3.614 (3) Šin (II). In the crystal of (II), a pair of 4-meth-oxy-benzene-sulfonate anions are bridged by Owater-H⋯Osulfonate hydrogen bonds, forming loops with an R 2 4(8) motif. These four-membered units are then linked to the cations by a number of C-H⋯O hydrogen bonds, forming slabs lying parallel to the ab plane.