Metal nanoparticle assisted growth of assembled zinc oxide nanostructure by low temperature solution phase technique

Herein we report metal nanoparticle directed growth of assembled zinc oxide nanostructures by a facile solution phase route. Si substrates with silver nanoparticles are subjected to low temperature hydrothermal growth. Coulombic attraction resulted in migration of Zn growth species onto Ag nanoparticle surface. SEM analysis revealed preferential nucleation and growth of zinc oxide nanostructures on Ag nanoparticles. Longer reaction period lead to formation of mulberry like assembled ZnO nanostructures. XRD analysis confirmed growth of zinc oxide nanostructures. The formed ZnO nanostructures exhibit well defined band edge PL peak corresponding to excitonic recombination. © 2016 Elsevier B.V.

NiO hybrid nanoarchitecture-based pseudocapacitor in organic electrolyte with high rate capability and cycle life

A 3D hierarchical NiO nanostructures with combined microstructure of nanoflakes and nanoflowers have been fabricated on carbon fibre cloth (CFC). Unique nano-micro structural features of NiO/CFC electrode showed an enhanced electrochemical activity in organic electrolyte (1 M tetraethylammonium tetrafluorborate (TEABF4) in propylene carbonate) in terms of rate capability, specific energy and power performance as well as potential limit. The electrode showed a specific capacitance of 170 Fg−1 for a current density of 5 Ag−1. Configured as a two-electrode symmetric supercapacitor, the device showed a specific capacitance of 34.9 Fg−1 at 1 Ag−1 current density. It delivered a maximum specific energy density of 19.4 Wh kg−1 at a high power density of 1002.8 W kg−1 at a constant current density of 1 Ag−1. The cell is also capable of long-term cycling stability with an efficiency of 58 % after 25,000 cycles with a potential window of 0 to ±2 V. This superior electrochemical activity of the NiO electrode is due to their structural benefits of well-connected hybrid nano/mesoporous structure and rapid ion intercalation within the porous electrode surface

NiO hybrid nanoarchitecture-based pseudocapacitor in organic electrolyte with high rate capability and cycle life

A 3D hierarchical NiO nanostructures with combined microstructure of nanoflakes and nanoflowers have been fabricated on carbon fibre cloth (CFC). Unique nano-micro structural features of NiO/CFC electrode showed an enhanced electrochemical activity in organic electrolyte (1 M tetraethylammonium tetrafluorborate (TEABF4) in propylene carbonate) in terms of rate capability, specific energy and power performance as well as potential limit. The electrode showed a specific capacitance of 170 Fg−1 for a current density of 5 Ag−1. Configured as a two-electrode symmetric supercapacitor, the device showed a specific capacitance of 34.9 Fg−1 at 1 Ag−1 current density. It delivered a maximum specific energy density of 19.4 Wh kg−1 at a high power density of 1002.8 W kg−1 at a constant current density of 1 Ag−1. The cell is also capable of long-term cycling stability with an efficiency of 58 % after 25,000 cycles with a potential window of 0 to ±2 V. This superior electrochemical activity of the NiO electrode is due to their structural benefits of well-connected hybrid nano/mesoporous structure and rapid ion intercalation within the porous electrode surface

Silver molybdate: an excellent optical limiting material under nanoregime for photonic device application

Abstract There is a mounting demand for nonlinear optical materials with superior optical limiting performance which has a noticeable impact on protecting the delicate optical components from laser-induced damage. Transition metal molybdates have garnered attention in the nonlinear optics field due to their outstanding optical and luminescent properties, which give rise to widespread applications in next-generation optoelectronics devices. The structural confirmation of the as prepared silver molybdate nanoparticles were made by XRD and Raman spectroscopy analysis. The linear optical properties and the band gap of the synthesized material were studied using UV–Visible and photoluminescence spectroscopy. SEM analysis revealed the pebble like morphology of the silver molybdate nanostructures. The nonlinear responses of the samples were studied using open aperture z-scan approach with Nd:YAG pulsed laser (532 nm, 9 ns, 10 Hz). The sample exhibits reverse saturable absorption pattern attributed to the two photon absorption (2PA) mechanism. The obtained OL threshold value is in the order of 1012 which is suitable for fabricating optical limiters in nano second pulsed laser regime

Enhanced Optical Nonlinearity in Bi³⁺-Doped CePO₄ Nanostructures for Optical Limiting Applications

Pure and Bi3+-doped CePO4 were synthesized by the simple co-precipitation method. Successful dopant incorporation into the host lattice of orthophosphate without altering the crystalline structure was confirmed by structure analysis, X-ray diffraction, and Raman characterization. Morphological investigation was done using HR-SEM which portrays the co-existence of nanospheres and nanorods in doped CePO4 and only nanospheres in pure CePO4. X-ray photoelectron spectroscopy studies confirm the +3 oxidation state of Ce3+ and Bi3+ with the presence of a trace amount of Ce4+ in the as-prepared nanoparticles. Vibration sample magnetometer studies show weak ferromagnetic behavior of the nanostructures at room temperature. The absorption band in the wavelength range 200–300 nm accounts for 4f–5d electronic transition, and a red shift in the band edge is due to the increase in the band gap with the addition of the dopant. Photoluminescence emission spectra show broad blue-green emission owing to transition of Ce3+ from the excited state to the ground state and also due to oxygen vacancy. The nonlinear optical absorption and optical limiting (OL) behaviors of Bi3+-doped cerium orthophosphate (CePO4) were investigated using an open-aperture (OA) Z-scan technique under an excitation source of 532 nm nanopulsed lasers. The recorded OA transmittance curve reveals a transition from saturable absorption to reverse saturable absorption in pure CePO4 at 2.46 GW/m2, whereas all the doped samples exhibit RSA attributed to 2PA. The increase in the nonlinear absorption (NLA) coefficient with on-axis intensity and the availability of the near resonant energy state due to the Bi3+ dopant ensure the sequential 2PA (1PA + ESA) phenomenon. Compared to pure CePO4, doped nanostructures show improved NLA coefficients due to the availability of the defect state and oxygen vacancies in Bi3+-doped CePO4. Interestingly, a lower OL threshold (OLT) of 0.14 × 10–13 W/m2 is observed in 0.3% Bi3+-doped CePO4. The lower OLT value of Bi3+-doped CePO4 ensures its potential candidature for OL applications in protecting optical sensors and human eyes