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Water management is one of the obstacles in the development and commercialization of proton exchange membrane fuel cells (PEMFCs). Sufficient humidification of the membrane directly affects the PEM fuel cell performance. Therefore, 2 different hydrophobic polymers, polydimethylsiloxane (PDMS) and (3-Aminopropyl) triethoxysilane (APTES), were tested at different percentages (5, 10, and 20 wt.%) in the catalyst layer. The solution was loaded onto the surface of a 25 BC gas diffusion layer (GDL) via the spraying method. The performance of the obtained fuel cells was compared with the performance of the commercial catalyst. Characterizations of each surface, including different amounts of PDMS and APTES, were performed via scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analyses. Molecular bond characterization was examined via Fourier transform infrared spectroscopy (FTIR) analysis and surface hydrophobicity was measured via contact angle measurements. The performance of the fuel cells was evaluated at the PEM fuel cell test station and the 2 hydrophobic polymers were compared. Surfaces containing APTES were found to be more hydrophobic. Fuel cells with PDMS performed better when compared to those with APTES. Fuel cells with 5wt.% APTES with a current density of 321.31 mA/cm2and power density of 0.191 W/cm2, and 10wt.% PDMS with a current density of 344.52 mA/cm2and power density of 0.205 W/cm2 were the best performing fuel cells at 0.6V.

The ZnO/TiO2 solution of the thin-film photocatalyst was prepared by using the sol-gel method. The prepared solution was coated on a quartz plate by using the dip-coating method. For the characterization of synthesized ZnO/TiO2 photocatalyst, SEM-EDS, XRD and chronoamperometty measurements were used. To determine photocatalytic activity and kinetic model studies, the degradation of Orange G dye which is frequently used in the textile industry on ZnO/TiO2 photocatalyst was investigated. Using the results of kinetic experiments by examining the effects of different initial dye concentrations, temperature and light intensities, the degradation of Orange G dye on ZnO/TiO2 photocatalyst was found to be in accordance with the Network Kinetic Model, and the calculated equilibrium constant and activation energies of the ZnO/TiO2 thin film photocatalyst arc 20.02 and 16.16 kJ/mol, respectively. (C) 2020 Elsevier B.V. All rights reserved.