http://nopr.niscpr.res.in/handle/123456789/39730 2026-03-14T12:39:01Z http://nopr.niscpr.res.in/handle/123456789/43260 Title: Rapid synthesis of Tb³⁺-doped gadolinium oxyhydroxide and oxide green phosphors and their biological behaviour Authors: Wani, Saima; Majeed, Shafquat; Shivashankar, S A Abstract: Green phosphors based on terbium doped GdOOH and Gd₂O₃ powders are prepared through a rapid microwave-assisted solution based method using ethanol as a solvent and without using any surfactants. The as-prepared Tb³⁺:GdOOH powders are crystalline and show a flower-like morphology comprising many two-dimensional flake-like structures. The as-prepared powders show good luminescence properties under UV excitation and their conversion to Tb³⁺:Gd₂O₃ by annealing takes place at modest temperatures. A considerable increase in luminescence intensity is observed for the annealed powders, which is ascribed to phase change from oxyhydroxide to oxide as well as an increase in crystallinity as a result of annealing. Cytotoxicity studies reveal that the as-prepared powders show considerable toxicity towards the cells, whereas the annealed powders do not hamper the cell growth. Page(s): 1285-1292 2017-12-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/43259 Title: Photocatalytic decolourisation of a toxic dye, Acid Blue 25, with graphene based N-doped titania Authors: Gupta, Susmita Sen; Chakrabortty, Dhruba Abstract: This study investigates adsorption of Acid Blue 25 dye and photocatalytic decolourisation with graphene based nitrogen doped TiO₂. The prepared material has been characterised by XRD, BET, DRS, PL, TEM and XPS study. The photocatalytic reaction was carried out after the attainment of adsorption equilibrium between graphene based nitrogen doped TiO₂ and dye. The photocatalyst dose, initial dye concentration and solution pH are found to influence both the processes. The percentage decolourisation increases on increase of amount of catalyst from 95.57% (load: 0.125 g L^-1) to 99.91% (load: 0.75 g L^-1). However, further increase of the catalyst dose to 1.25 g L^-1 leads to decrease in the extent of decolourisation. The decolourisation is favoured by lower dye concentration. The solution pH influences the reaction process and at pH 3.0, the material can decolourise almost 99% of the dye within 180 min of irradiation time. COD results reveal ~99% mineralisation of the dye on 420 min of irradiation. The percentage decolourisation of the dye is higher with graphene based nitrogen doped TiO₂ as compared to NTiO₂ or TiO₂ P25. The adsorption interaction follows the Lagergren first order model and modified Langmuir-Hinselwood model is preferably followed by dye decolourisation. Page(s): 1293-1301 2017-12-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/43258 Title: Thionine-functionalized graphene oxide nanosheet as an efficient electrocatalyst for NADH oxidation and H₂O₂ reduction Authors: Ensafi, Ali A; Zandi-Atashbar, Navid; Sarsahra, Zeynab Ahmadi; Rezaei, Behzad Abstract: Thionine-functionalized graphene oxide (Th-GO) has been successfully prepared for use as an efficient electrocatalyst in the electrochemical detection of hydrogen peroxide and nicotinamide adenine dinucleotide (NADH), and subsequently characterized by FT-IR spectroscopy, X-ray diffraction, transmission and scanning electron microscopy, and electrochemical methods. Electrochemical studies reveal that the carbon paste electrode modified with Th-GO decreases the working potentials to 0.24 V and 0.00 V towards oxidation of NADH and reduction of H₂O₂, respectively. Two linear ranges of 2.0–200 µmol L^–1 and 200–500 µmol L^–1 and a detection limit of 0.43 µmol L^–1 have been obtained for NADH analysis. These quantitative data for H₂O₂ determination are 2.0–3500 µmol L^–1 and 1.3 µmol L^–1 respectively. Th-GO/CPE shows satisfactory results in terms of repeatability, reproducibility, and selectivity towards NADH and H₂O₂ analysis in both buffer and real sample. Page(s): 1302-1309 2017-12-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/43257 Title: Novel acrylate polymer nanocomposites with nano CdS Authors: Patel, Nirmal N; Patel, Kaushal P; Patel, Rajnikant M Abstract: Homopolymer of 4-chloro-3,5-dimethylphenylacrylate (CDMPA) and <em>p</em>-chlorophenylmethacrylate (PCPMA) and their copolymers with different compositions are synthesized by free radical polymerization technique using 2,2-azo-bis-isobutyronitrile as initiator in N,N-dimethylformamide as solvent at 70 °C. Their polymeric nanocomposites with nano CdS have then been synthesized by in-situ technique. Characterisation of the monomers, polymers and their polymeric nanocomposites with nano CdS have been done by spectroscopic methods. X-ray diffraction studies show cubic structured nanocrystalline CdS with 2.41-3.16 nm diameter. Compositions of the copolymers are determined by ¹H-NMR. Linear methods, namely, Finemann-Ross, inverted Finemann-Ross, Kelen-Tudos and extended Kelen-Tudos have been used for the determination of reactivity ratio of the monomers. Thermal analyses of the virgin polymers and their polymeric nanocomposites with nano CdS have been carried out by thermogravimetric studies. The kinetic parameters of virgin polymers and polymeric nanocomposites with nano CdS are determined by Broido method and Coats-Redfern method. Antimicrobial screening of homo and copolymers and one of the polymer nanocomposite with nano CdS has been studied against different microorganisms. Page(s): 1310-1316 2017-12-01T00:00:00Z