Gamma radiations have emerged as a potential tool to degrade and decolorize the industrial effluents containing synthetic dyes in eco friendly and efficient manner. The dose and exposure time required to achieve the efficient decolration are quite high using gamma radiations alone during gamma radiolysis of synthetic dyes. Studies have revealed that, it can be brought down significantly on addition of H2O2 as it enhances the degree of decoloration. This happens due to the formation of highly oxidizing •OH radicals that are formed due to rapid reaction of H2O2with hydrated electrons formed during radiolysis of water. Further as the dose of H2O2 increases, extent and rate of decoloration also increases up to a certain value referred to as critical dose. But further increase in dose of H2O2 beyond this critical value affects the extent of decoloration adversely. In present communication, the gamma radiation induced decoloration of Methylene Blue, Malachite Green and Indigo Carmine dyes was achieved using various doses of H2O2. It was observed that, the value of H2O2 Critical dose required for efficient decoloration varies from dye to dye indicating its dependence on structure and concentration of dye solutions.

Eu(2+)-doped Ba3Si6O12N2 phosphors were prepared successfully via a modified solid-state diffusion method. The phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence measurements. These phosphors were effectively excited at 355 nm and an intense emission peaking in the range 480 nm to 525 nm in the blue region was observed. The optimized dopant concentration was determined to be 1 mol% of Eu(2+) ion. The colour coordinates for phosphor were found to be (0.196, 0.326) in the blue region. This phosphor may find application for near-ultraviolet (NUV) excited lamp phosphors. The thermoluminescence study shows the complex glow curve. Trapping parameters (activation energy and frequency factor) were calculated for individual deconvoluted peaks by Chen's peak shape method, the initial rise method and the whole glow peak method.

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Highly efficient new vanadate phosphor A2NaMg2V3O12 (A = Ba & Sr) doped with rare earth element Dysprosium (Dy) was synthesized at high temperature via solid-state method successfully and the formed compound was confirmed by X-ray diffraction method. Photoluminescence measurements revealed that Sr2NaMg2V3O12 phosphor doped with Dy is excited by near ultraviolet light ranging from 300 nm to 380 nm efficiently in order to realize the emission in visible spectrum (in the range 400 nm −570 nm. Ba2NaMg2V3O12: Dy phosphor also showed emission at 569 nm on excitation at 325 nm. Hence this prepared phosphor can find application as a green emitting phosphor in solid state lighting area.