ذخيره‌سازي هيدروژن بر روي نانوكامپوزيت‌هاي پالاديم گرافن اكسيد و پالاديم گرافن اكسيد كاهش‌يافته به‌روش‌هاي شيميايي و الكتروشيميايي

In this research, the hydrogen storage process in graphene-based Palladium (Pd) nanocomposites was investigated an‎d eva‎luated using both chemical an‎d electrochemical methods. In the first part, chemical hydrogen storage was performed via the Benkeser reduction reaction, an‎d the comparative effect of two amine agents—ethylenediamine (EDA) an‎d diethylamine (DEA)—on the hydrogen storage capacity was examined. Thermogravimetric Analysis (TGA) was employed to estimate the amount of stored hydrogen in this method. In the second part, for electrochemical hydrogen storage, Palladium/reduced Graphene Oxide (Pd/rGO) nanocomposites were synthesized through in-situ chemical reduction of Graphene Oxide (GO) an‎d Palladium ions using ascorbic acid under reflux conditions at 90–95 °C. Supplementary reduction was then carried out using a tube furnace under a nitrogen atmosphere. The amount of stored hydrogen in this method was determined by calculating the area under the desorption peak in Cyclic Voltammetry (CV) tests. To confirm the structure of the synthesized compounds an‎d their detailed characterization, various techniques were utilized, including Fourier-Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive X-ray Spectroscopy (EDX), Elemental Mapping, Inductively Coupled Plasma Mass Spectrometry (ICP-MS), an‎d UV-Visible Spectroscopy. Furthermore, the electrochemical behaviors of the samples were analyzed using Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS), an‎d stability tests. The results demonstrated that the chemically stored hydrogen capacity was 16.19 wt% for the Pd/GO sample hydrogenated with ethylenediamine an‎d 13.78 wt% for the sample hydrogenated with diethylamine. Additionally, the electrochemical hydrogen storage capacity of the Pd/rGO nanocomposite was calculated to be 8917.2 mC/(mg·cm²). Moreover, the stability eva‎luation of the Pd/rGO sample revealed that the nanocomposite retained 97.64% of its initial capacity after 3000 cycles, indicating the excellent stability of this structure in electrochemical processes.

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معصومه جديدي نژاد , محمدمحسن مومني هامانه