Ayşe Bayrakçeken Yurtcan

Graphene-based technologies for energy applications, challenges and perspectives

Here we report on technology developments implemented into the Graphene Flagship European project for the integration of graphene and graphene-related materials (GRMs) into energy application devices. Many of the technologies investigated so far aim at producing composite materials associating graphene or GRMs with either metal or semiconducting nanocrystals or other carbon nanostructures (e.g., CNT, graphite). These composites can be used favourably as hydrogen storage materials or solar cell absorbers. They can also provide better performing electrodes for fuel cells, batteries, or supercapacitors. For photovoltaic (PV) electrodes, where thin layers and interface engineering are required, surface technologies are preferred. We are using conventional vacuum processes to integrate graphene as well as radically new approaches based on laser irradiation strategies. For each application, the potential of implemented technologies is then presented on the basis of selected experimental and modelling results. It is shown in particular how some of these technologies can maximize the benefit taken from GRM integration. The technical challenges still to be addressed are highlighted and perspectives derived from the running works emphasized.

Investigation of the Thermal Behavior of Polypyrrole/Carbon Nanotube Composites and Utilization as Capacitive Material or Support for Catalysts

In this study, polypyrrole (PPy)/carbon nanotube (CNT) composites were synthesized by in situ chemical oxidative polymerization of a pyrrole monomer on CNT. Two different types of CNT having different structural properties were used. The composites were characterized using BET surface area analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) techniques. Thermal decomposition kinetics of PPy/CNT composites was studied by thermal gravimetric analysis techniques (TG/DTG (differential thermal gravimetric)) at different heating rates (2.5, 5, 7.5, and 10 K min−1). Kinetic parameters of the composites were obtained from the TG and DTG curves using the Kissinger–Akahira–Sunose (KAS) and Flynn–Wall–Ozawa (FWO) models. The electrochemical capacitive properties of the composites were investigated by the cyclic voltammetry (CV) technique. Pt nanoparticles were decorated on the plain CNTs and composite materials via the microwave irradiation method.

SB12 Assisted Synthesis of Nano CuO via Precipitation Method in Different Reaction Environments

In this study, CuO was synthesized via precipitation method by using Cu (CH3COO)2.H2O as precursor. KOH+NH3, KOH and NaOH were used as reactants and zwitterionic 3-(N,N-dimethyldodecylammonio) propane-sulfonate (SB12) as surfactant in the synthesis procedure. The samples were calcined at 500°C. All prepared CuO structures were characterized by X-ray diffraction (XRD), thermal gravimetric analysis (TGA), Fourier Transform Infrared (FTIR) spectra, and scanning electron microscopy (SEM) techniques. Electrochemical characterization was performed by cyclic voltammetry (CV). CuO showed different nanostructures according to the characterization results. Furthermore, electrochemical properties of the resulting structures were investigated. The specific capacitances of the CuO structures in different environments were determined by using CV technique in the order of: KOH+NH3>KOH>NaOH.