T. Dhanasekaran

Synthesis, growth and photoluminescence behaviour of Gd2O2SO4:Eu3+ nanophosphors: the effect of temperature on the structural, morphological and optical properties

Gd2(SO4)3·8H2O, Gd2O2SO4, and Gd2O2SO4:Eu3+ nanoparticles have been synthesized in the presence of Gd3+ ions and sodium dodecyl sulphate (SDS) by the simple complexation-thermal decomposition (CTD) method. The structural analysis, growth mechanism and optical properties of the Gd2(SO4)3·8H2O, and Gd2O2SO4 are described by the diffraction pattern, functional group analysis, Raman, morphology, elemental analysis, and absorbance spectra. The most intriguing factor was that the Gd2O2SO4 nanoplates are in the range of 42–50 nm without adding any external stabilizer. The results revealed that the Gd2O2SO4 nanoparticles with an orthorhombic structure have a band gap of 3.12 eV. Furthermore, Gd2O2SO4 shows an intense red photoluminescence associated with the 5D0 → 7F2 transition in the presence of Eu3+. The results suggest that the Gd2O2SO4:Eu3+ nanophosphors, may have a beneficial approach in the field of biomedical application as luminescent probe/labels.

Manganese sesquioxide to trimanganese tetroxide hierarchical hollow nanostructures: effect of gadolinium on structural, thermal, optical and magnetic properties

Various hollow manganese oxide (bixbyite Mn2O3 and hausmannite Mn3O4) nanoparticles (NPs) with different morphologies were obtained from a single precursor, manganese oxalate (MnC2O4). To synthesize a Mn3O4 stacked nanostructure rather than coral-like Mn2O3 nanospheres, as synthesized MnC2O4 was thermally decomposed at 700 °C in the presence of Gd3+, through the oriented arrangement mechanism. The formation process and structural variation arising from varying the thermal treatment (450 °C and 700 °C) and the cationic dopant Gd3+ were analyzed by FTIR, TGA, and XRD. The unexpected size reduction, and significant physicochemical properties were analyzed using various techniques such as FESEM coupled with EDAX, HR-TEM, DRS-UV-vis, EPR, EIS and VSM. The addition of gadolinium induces particle size reduction and a phase transition from cubic Mn2O3 to tetragonal Mn3O4, which leads to the suppression of the electrical conductivity, and changes in the optical band gap. The prepared Mn3O4 nanocrystals exhibit ferromagnetic behavior below Tc ≈ 45 K and weak paramagnetic behavior at room temperature.

Facile solvothermal decomposition synthesis of single phase ZnBi38O60 nanobundles for sensitive detection of 4-nitrophenol

We have developed the facile solvothermal decomposition route to fabricate a single phase zinc bismuthate (ZnBi38O60) binary composite nanostructure. Interestingly, the proposed technique provides a new pathway to synthesize similar multi compound oxide materials. The prepared ZnBi38O60 was characterized by different analytical techniques. Typical crystalline phase and chemical composition were confirmed using X-ray diffraction (XRD) and X-ray photoelectron spectra. Unique nanobundle morphology of the ZnBi38O60 was confirmed by field emission scanning electron microscopy (FE-SEM) and high resolution transmission electron microscopy (HR-TEM). A glassy carbon electrode modified using ZnBi38O60 nanobundles as the electrocatalyst was used to qualitatively and quantitatively determine 4-nitrophenol (4-NP) using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The modified electrode exhibits better sensitivity (1.024 μA μM−1 cm−2) and limit of detection (LOD) 35 × 10−9 M. Thereby it can be concluded that ZnBi38O60 nanobundles could be another choice of electrocatalyst for 4-NP determination and can be extended to various nitro containing analytes.

Synthesis & characterization of Bi7.38Ce0.62O12.3 and its optical and electrocatalytic property

Bismuth cerium oxide was synthesized by thermal decomposition method. The material was characterized by X-ray diffraction technique, DRS UV-Vis, Raman spectral methods and FE-SEM. The electrocatalytic sensing activity of bismuth cerium oxide modified GCE toward 4-nitrophenol exhibits better activity than the bare GCE. The modified electrode shows higher anodic current response with lower potential.Bismuth cerium oxide was synthesized by thermal decomposition method. The material was characterized by X-ray diffraction technique, DRS UV-Vis, Raman spectral methods and FE-SEM. The electrocatalytic sensing activity of bismuth cerium oxide modified GCE toward 4-nitrophenol exhibits better activity than the bare GCE. The modified electrode shows higher anodic current response with lower potential.

Preparation and Optical Studies of Layered Double Hydroxides for Photo Catalytic Degradation of Organic Dyes

Over the past decades metal-oxide played in important role in electrocatalyst and photocatalyst. The Mn-Ru layered double hydroxides are prepared by facile one step hydrothermal method. The prepared sample was characterized by variety of techniques. Such as X-Ray Diffract meter was used to determine the phase purity and Crystal structure of the prepared sample. FT-IR is reveals the present of functional groups and DRS UV spectroscopy used to conclude the band gap energy of the prepared materials. The surface morphology was analyzed by using FESEM microscope. The prepared Mn-Ru are layered double hydroxides was further used to photo catalytic degradation of organic dyes.