Green synthesis (hydrothermal/solvothermal) synthesis of carbon quantum dots;catalytic performance of carbon quantum dots in hydrolisis reactions in dimethyl aminborane and sodium boron hydridetheoretical and experimental investigation

Chemical hydrides used as hydrogen storage are seen as one of the most effective ways of safely storing hydrogen in chemical compounds, transporting it efficiently and releasing hydrogen when desired. In this thesis study; Dimethyl aminborane (DMAB), which has a high hydrogen storage capacity and is the most promising among hydrogen storage materials, was used in addition to sodium borohydride (SBH), which is the most widely used chemical hydrogen storage material so far. In addition, the catalytic performances of SBH and DMAB on hydrogen production were investigated by doping Ni metal on carbon quantum dots (CQD) obtained from urea under hydrothermal and solvothermal conditions and hydrolysis of the obtained catalysts (different loading type, different NaOH effect, different catalyst amount, different borohydride concentration, temperature and reusability). In addition, in this thesis, the theoretical hydrolysis was carried out at different temperatures with molecular dynamics programme and teric calculation was performed for both NaBH4 and DMAB. It has been observed that this is in agreement with the hydrolysis results obtained in experimental studies. Finally, the prepared metal nanoclusters were analysed by ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry), XRD (X-Ray Diffraction), XPS (X-Ray Photoelectron Spectroscopy), TEM (Transmission Electron Microscopy), The catalysts were characterised using advanced analytical and spectroscopic methods such as TEM/EDX (Transmission Electron Microscopy/Energy Dispersive X-ray Spectroscopy) and ATR-IR (Fourier Transform Infrared Spectroscopy). After examining the reusability performance of the prepared catalysts in the complete degradation reaction of hydrazine-borane, catalytic reactions were carried out at different temperatures and the activation parameters for the most efficient metal nanocluster (Ea: Activation Energy; ΔH*: Activation Enthalpy; ΔS*: Activation Entropy) were calculated.