Fabrication of Gold Nanoparticles/Polypyrrole/HRP Electrode for Phenol Biosensor by Electropolymerization

A phenol enzyme biosensor was fabricated in this research using disposable screen-printed carbon electrode modified with gold nanoparticles (AuNPs), polypyrrole (PPy) and immobilized horseradish peroxidase (HRP) by electropolymerization method. The physical and chemical properties of the modified electrode was characterized by scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) while electrochemical analysis was performed with amperometry. The experimental parameters were optimized with regard to the increasing concentration of AuO and enzyme amounts. The obtained result proved that AuNPs/Polypyrrole composite matrix could not only appropriately immobilize HRP, but also retain its bioactivity. Furthermore, the presence of gold nanoparticles provides enhanced electrochemical responses. The proposed method was simple, convenience to use, and illustrated high sensitivity

Effect of Silver Nanoparticle Size on Efficiency Enhancement of Dye-Sensitized Solar Cells

Titanium dioxide/silver (TiO2/Ag) composite films were prepared by incorporating Ag in pores of mesoporous TiO2 films using a photoreduction method. The Ag nanoparticle sizes were in a range of 4.36–38.56 nm. The TiO2/Ag composite films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The TiO2 and TiO2/Ag composite films were then sensitized by immersing in a 0.3 mM N719 dye solution and fabricated for conventional dye-sensitized solar cells (DSCs). J-V characteristics of the TiO2/Ag DSCs showed that the Ag nanoparticle size of 19.16 nm resulted in the short circuit current density and efficiency of 8.12 mA/cm2 and 4.76%

Processing and characterization of printed AgPd/PZT/AgPd microdisks for piezoelectric vibration energy harvesters

National audienc

A Combined Effect of Plasmon Energy Transfer and Recombination Barrier in a Novel TiO2/MgO/Ag Working Electrode for Dye-Sensitized Solar Cells

Novel TiO2/MgO/Ag composite electrodes were applied as working electrodes of dye-sensitized solar cells (DSSCs). The TiO2/MgO/Ag composite films were prepared by dip coating method for MgO thin films and photoreduction method for Ag nanoparticles. The MgO film thicknesses and the Ag nanoparticle sizes were in ranges of 0.08–0.46 nm and 4.4–38.6 nm, respectively. The TiO2/MgO/Ag composite films were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The TiO2/MgO/Ag composite electrodes were sensitized by immersing in a 0.3 mM of N719 dye solution and fabricated for conventional DSSCs. J-V characteristics of the TiO2/MgO/Ag DSSCs showed that the MgO film thickness of 0.1 nm and the Ag nanoparticle size of 4.4 nm resulted in maximum short circuit current density and efficiency of 8.6 mA/cm2 and 5.2%, respectively. Electrochemical Impedance Spectroscopy showed that such values of short circuit current density and efficiency were optimal values obtained from plasmon energy transfer by 4.4 nm Ag nanoparticles and recombination barrier by the ultrathin MgO film

Processing and characterization of printed AgPd/PZT/AgPd microdisks for piezoelectric vibration energy harvesters

International audienc

Improvement of densification and electromechanical properties of screen printed PZT-LBCu micro-ceramics

International audienc

Mechanically alloyed β-Ag2_{2}Te in thermoelectric Bi2_{2}Se0.01_{0.01}Te2.99_{2.99}

We show that the thermoelectric compound Ag0.5Bi1.5Se0.15Te2.85 can be prepared by mechanical alloying from elemental Ag, Bi, Se and Ag powers. By using complementary microstructural characterization techniques, i.e. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, scanning transmission electron microscopy and energy dispersive X-ray spectroscopy, it was possible to find the exact composition of each phase formed in the compound. The phases formed were Bi2Se0.01Te2.99 and polymorphs of AgTe including an unusual β-Ag2Te phase

Kinetic Studies of Atom Transfer Radical Polymerisations of Styrene and Chloromethylstyrene with Poly(3-hexyl thiophene) Macroinitiator

Poly(3-hexyl thiophene)-b-poly(styrene-co-chloromethylstyrene) copolymers, to be used as a prepolymer for preparing donor-acceptor block copolymers for organic solar cells, have been synthesised by reacting P3HT macroinitiators with styrene and chloromethylstyrene via three types of atom transfer radical polymerisation (ATRP) systems, which are (1) a normal ATRP, (2) activators generated by electron transfer (AGET), and (3) a simultaneous reverse and normal initiation (SR&NI). The kinetics of these ATRP systems were studied as a function of monomers to the macroinitiator molar ratio. It was found that all of the three types of ATRP systems led to first order kinetics with respect to monomers. The highest rate constant (k) of 3.4 × 10−3 s−1 was obtained from the SR&NI ATRP system. The molecular weights of the product determined by the GPC were lower than were the theoretical values. The result was discussed in light of the chain transfer reaction to the poly(chloromethylstyrene) repeating units. Morphology of the synthesized block copolymers, examined by an atomic force microscopy (AFM), were also compared and discussed