A self-poled rGO–Ag/PVDF nanocomposite based nanogenerator is shown with proper material characterization that can light twenty commercial blue LEDs, charge capacitors and harvest biomechanical energy.

This work reports a highly sensitive and selective nonenzymatic detection of glucose that has been achieved by hybridization of 1D α-MnO2 nanorods modified with surface decoration of Co3O4 nanoparticles. The rational design and controlled synthesis of the hybrid nanostructures are of great importance in enabling the fine tuning of their properties and functions. First-principles-based periodic hybrid unrestricted HSE06 DFT with Grimme’s long-range dispersion corrections are employed to compute the equilibrium crystal structures and electronic properties (i.e., band structure, Fermi energy level, and density of states) of both materials. These calculations reveal that both the α-MnO2 and the Co3O4 materials are indirect band gap semiconductor, and the band gap is about 2.89 and 3.18 eV, respectively. The α-MnO2/Co3O4 hybrid nanostructure has been synthesized by a simple and economical hydrothermal method. Compared with the performances of pure components MnO2 nanorods and Co3O4 nanoparticles, these hybrid nanostructures demonstrated a maximum electrooxidation toward glucose. The glucose-sensing performances of fabricated hybrid structures were measured by cyclic voltammetry (CV) and chronoamperometry. The synthesized α-MnO2/Co3O4 electrode exhibited a high sensitivity of 127 μA mM–1 cm–2 (S/N = 3) with a detection limit of 0.03 μM, wide linear range from 60 μM to 7 mM of glucose, with a short response time of less than 5 s. The favorable properties of the nanostructure fortify its potential utilization in the clinical detection of diabetes.

No abstract

In this research paper we present a comparative study on the enhanced piezoelectric performance between Carbon Nanotubes (CNT)/PVDF nanocomposite as well as Iron-Reduced Graphene Oxide (Fe-RGO)/PVDF nanocomposite. The enhanced performance is realized by a unique device structure, in which the bottom electrode is physically not in contact with the piezoelectric film until external excitation is applied. FTIR characterization shows the enhancement of polar crystallization phases due to electrostatic interactions in PVDF by the addition of CNT and Fe-RGO. Raman Spectroscopy indicates the formation of good quality Fe-RGO nanosheets and also shows high crystalline quality of CNTs. Raman Spectroscopy identifies the interaction between CNTs and Fe-RGO nanosheets with the polymer that supports the piezoelectric current generation mechanism. Conductivity measurements show that addition of CNT and Fe-RGO in PVDF increases the conductivity of the nanocomposite films. The CNT/PVDF and Fe-RGO/PVDF piezoelectric energy harvesting device produced an open circuit output voltage of 2.5 V and 1.2 V respectively. A short circuit rectified current of nearly 700 nA and 300 nA was detected by the CNT/PVDF and Fe-RGO/PVDF based piezoelectric energy harvesting device.

Porous spherical bundles of W 18 O 49 nanorods with rich oxygen vacancy has been generated by a facile, low cost solvothermal approach and subsequently characterized for energy storage application. The remarkable electrochemical activity of W 18 O 49 nanostructure is referred to the development of oxygen vacancy and nanostructure network leading to maximize the active sites and surface area for the electrolyte ions. A specific capacity of 470 mA h /g at scan rate of 1mV/s and 452 mA h /g at a very high current density of 1.25 A/g were calculated in 1M H 2 SO 4 electrolyte. The experimental results revealed that surface oxygen vacancy enhances the adsorption and reaction site for electrolyte ions indicating the good electrochemical activity of the W 18 O 49 nanostructure materials. GCD summarizes an intermediate mechanism of pseudocapacitor-battery for W 18 O 49 nanorods. These findings will have a profound effect on understanding and mechanism of the surface induced vacancy to the process of electrochemical activity in terms of energy storage.