Development of graphene supported catalyst nanoparticles for polymer electrolyte membrane (PEM) fuel cells

Catalyst nanoparticles inside PEM fuel cells are generally supported with a powdered material which has a high surface area, high mechanical and thermal stability, and preferably high conductivity. Vulcan®XC-72 which is a type of carbon black (CB) is the most conventional material that is used as catalyst support. It has a BET specific surface area of 250 m2.g−1 and conductivity of 4-7.4 S.cm-1. The usage of CB in fuel cells is beneficial in terms of this tempting features, however, the lack of tolerance to carbon monoxide (CO) poisoning due to the presence of deep cracks in its structure creates a great problem inside a harsh fuel cell environment. Graphene, on the other hand, provides a large surface area and high conductivity while providing a large and stable surface support as a result of its two dimensional structure. In this thesis study, the influence of using graphene derivatives (graphene oxide (GO), thermally reduced GO (TRGO) and graphene nanoplatelets(GNP)) as catalyst support materials to the catalytic activity of platinum (Pt) nanoparticles and fuel cell performance was evaluated in combination with the utilization of various platinum impregnation methods (ascorbic acid, ethylene glycol reflux, sodium borohydride reduction). The synthesized materials were characterized by using XRD, Raman, FTIR, TEM, SEM, Cyclic Voltammetry (CV), BET Surface Area Analysis, XPS and Fuel Cell Performance Test. Ethylene glycol method and GO were determined to be the most effective impregnation method and the best catalyst support candidate respectively. Ethylene glycol reflux was further applied to impregnate Pt on Vulcan®XC-72.The results were compared with commercial Vulcan®XC-72 supported Pt nanoparticles and synthesized Pt/ Vulcan®XC-72

A Study on the Impact of Agile Leadership and Innovative Behaviors on Psychological Empowerment

This study focuses on the impact of agile leadership and innovative behaviours on psychological empowerment and its dimensions via a questionnaire form based on the "Agile Leadership Scale", "Innovative Behaviours Scale", and "Psychological Empowerment Scale". The study sample comprises 410 people in the Turkish information and communication industry. The data obtained were analysed with SPSS 21.0 with %95 credibility. Parametric test techniques were used, and the relationship between the scale scores was analysed by Pearson correlation, and regression analysis was used to analyse its effect. The analysis showed that agile leadership and innovative behaviours affect psychological empowerment and the dimensions of competence, autonomy and impact. However, no effect on the meaning dimension can be found. The study highlights the importance of agile leadership and innovative behaviour in encouraging psychological empowerment. The conclusion emphasises that agile improvement is essential to success and how to boost innovative behaviour and psychological empowerment in business. Organisations should take action to improve agile leaders, encourage innovative behaviour and boost psychological empowerment among employees. One of the limitations of the study is that it was conducted in only one sector. The results can be compared by conducting research in different sectors. Further studies can be carried out at regular intervals to obtain more comprehensive findings. In the study, 410 samples were reached. By reaching a larger sample, the results can be compared. New models can be created with different variables that affect psychological empowerment. In addition, different quantitative and qualitative methods can be used

Correction to: Electrosprayed catalyst layers based on graphene–carbon black hybrids for the next-generation fuel cell electrodes (Journal of Materials Science, (2017), 52, 4, (2091-2102), 10.1007/s10853-016-0497-0)

The article “Electrosprayed catalyst layers based on graphene–carbon black hybrids for the next-generation fuel cell electrodes,” written by Lale Işıkel Şanlı, Begüm Yarar, Vildan Bayram, and Selmiye Alkan Gürsel, was originally published electronically on the publisher’s internet portal (currently SpringerLink) on October 25, 2016, without open access