Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Conference Object Citation - Scopus: 2Co2 Capture by Pei-Impregnated Alumina Sorbents(ISRES Publishing, 2023) Turgut, Furkan; Kostik, Simge; Erdoğan, Barış; Çağlar, BaşarDirect air capture (DAC) or direct CO2 extraction from ambient air is a promising approach to reduce greenhouse gas emissions caused by both distributed (location independent) and point sources (location specific). Solid sorbents have been considered as more effective for DAC compared to the liquid counterpart since they have a faster kinetic and avoid volatile and heat losses due to the absence of evaporation of liquids. In this study, the alumina-supported polyethyleneimine (PEI) material was chosen as solid sorbents and their CO2 capture performance for different PEI loadings (20, 35, 50 wt%), flow rate (15, 30, 45 L/h) and adsorption temperatures (30, 40, 50, 60 °C) was investigated. Sorbents were prepared by using wetness impregnation method and their physical and chemical properties were characterized by several techniques such as N2 adsorption-desorption (surface area, pore size and volume), Scanning Electron Microscopy-SEM (surface morphology, surface chemical composition). The CO2 capture performance of sorbents were analyzed under different CO2 concentrations and the cyclic (adsorption-desorption) behavior of the sorbents were tested. The results show that alumina-supported PEI adsorbents are promising materials for CO2 capture with high CO2 adsorption capacity and stability. © 2023 Published by ISRES.Article Citation - Scopus: 1Optical and Surface Properties of Zinc Oxide Nanoparticles Dried by Conventional and Supercritical Ethanol Drying Techniques(Research India Publications, 2014) Egbuchunam, Theresa Obuajulu; Yetgin, Senem; Özmıhçı Ömürlü, Filiz; Balköse, DevrimZinc oxide (ZnO) nanoparticles were synthesized by conventional (ZnO-A) and supercritical ethanol drying (ZnO-B). Nitrogen adsorption/desorption analyses were performed to determine the surface areas of the powders. The specific surface area was 28.30m2/g and 10.61 m2/g for ZnO-A and ZnO-B respectively. The powders adsorbed very small amount of CO2with the conventionally dried powder adsorbing more CO2. Supercritical ethanol dried ZnO had ethanol on its surface which was eliminated by vacuum application at room temperature. Both powders had OH groups which were eliminated on heating up to 500°C under vacuum. However, OH groups were present in lower amounts in supercritical ethanol dried ZnO. The powders were characterized by UV-VIS optical absorption and room temperature photoluminescence spectroscopic analyses. The UV-VIS absorption spectrum showed an absorption band at 375nm due to ZnO nanoparticles. The photoluminescence spectrum of ZnO excited at 380nm exhibited three emission peaks: one at 424nm and 490nm corresponding to band gap excitonic emission and another located at 520nm due to the presence of singly ionized oxygen vacancies.