Synthesis of hierarchical structured Gd doped α-Sb2O4 as an advanced nanomaterial for high performance energy storage devices

Bimetallic oxide nanostructures (NS) of Gd_x: α-Sb₂O₄ (x = 5, 8, 10 wt.%) emerged as novel electrode material for batteries as they exhibit large specific capacity and cyclic stability. Crystal structure of Gd: α-Sb₂O₄ NS investigated by X-ray diffraction (XRD) patterns and identified as mixed orthorhombic phase. Surface chemical composition, binding energies of the metal oxides and incorporation of Gd into α-Sb₂O₄ NS analysed by XPS (X-ray photoelectron spectral) studies. Microstructure analysis reveals that distinctive flower/flake like arrays with agglomeration. Morphology, structure and physical/chemical properties of the resulting nanostructure were analysed by SEM (scanning electron microscopy), SEM-EDX (scanning electron microscopy-energy dispersive X-ray), BET (Brunauer-Emmett-Teller), XPS, UV-Visible and XRD studies. Electrochemical performances of Gd_x: α-Sb₂O₄ (x = 10 wt.%) in 6 M KOH aqueous solution dipped in three electrode system evaluated by CV (cyclic voltammetry), GCD (galvanostatic charge-discharge) and EIS (electrochemical impedance spectroscopy) measurements. The as-synthesized NS exhibited higher specific capacitance of 958 mAh/g at a current density of 0.15 A/g and excellent cyclic stability with 86.5% capacitive retention after 1000 cycles. Distinctive flower/flake like structure, large surface area, and abundant active sites of Gd_x: α-Sb₂O₄ NS could be the reason for significant increase in charge transfer and storage. In brief this work offers facile method to synthesize Gd_x: α-Sb₂O₄ NS are promising electrode materials for potential applications in high performance super capacitor.

Optical, Structural and Photoluminescence Properties of Gd x SrO: CdO Nanostructures Synthesized by Co Precipitation Method

To investigate the effect of Gd _x SrO: CdO (x = 0.1, 0.3, 0.4) nanostructures (NS), in the present work an attempt has been made to synthesize Gd_x SrO:CdO NS by co precipitation method. Structural properties were investigated by XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy), UV-Visible, XPS (X-ray photoelectron spectroscopy). XRD indicates having mixed phase of tetragonal crystal structure and SEM images indicate spherical shaped nanoparticles (NPs) of Gd _x SrO:CdO with average size laying in between ~100 nm to ~130 nm. FTIR spectra of Gd _x SrO: CdO NS show stretching and bending peaks of Gd-O-Gd, Cd-O-Cd and Sr-OH at ~1311 cm ^-1, ~1486 cm ^-1, ~ 3300 cm ^-1 and UV-visible optical absorptivity of Gd _x SrO:CdO show absorption maxima shift from 330 nm to 324 nm (blue shift) and edges at 352.4 nm, 348 nm and 346.3 nm respectively for Gd concentration varying between 0.1, 0.3 and 0.4. binding energies of the Gd 3d _3/2, Sr 3d _3/2 and Cd 3d _3/2, O1s and C1s observed at 150.8 eV, 141.6 eV, 410.1 eV, 529.6 eV and 282.4 eV respectively which confirms the chemical composition of NS. Photoluminescence (PL) spectrum of Gd _0.4 Sr _0.5 O Cd _0.1O NS exhibit broad peaks from 338 nm to 397 nm centred around 369 nm with various Gd, O, Sr and Cd related native defects. Emission band observed at UV- Visible region for Gd _0.3 Sr _0.5 O Cd _0.2 O NS PL emission spectra has two emission peaks at 369 nm (UV region) and 550 nm (Visible region). The transitions can be ascertained with shielding of 4f shells of Gd⁺³ ions by 6 s, 5d shells by the interaction of the other Gd⁺³ ions.