Synthesis, characterisation and catalysis applications of graphitic carbon nitride based metal organic framework nanocomposites

In this thesis, graphitic carbon nitride (g-C3N4) based Zeolitic Imidazolate Framework (ZIF) nanocomposites were synthesized for catalysis applications. In order to increase the catalytic activity, g-C3N4@ZIF-8 and g-C3N4@ZIF-9 nanocomposites were obtained by doping ZIF-8 and ZIF-9 nanoparticles into the g-C3N4 structure. The catalytic activity of the obtained nanocomposites in the removal of Alizarin Red S (ARS) and ketoprofen (KET) with the help of NaBH4 reducing agent in aqueous medium was investigated. g-C3N4@ZIF-8 and g-C3N4@ZIF-9 nanocomposites were investigated by various characterization methods. In this context, techniques such as Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-Ray Spectroscopy (EDX), UV-Vis DRS, X-Ray Photoelectron Spectroscopy (XPS) were used and zero charge point (pHpzc) measurements were performed. Dye and drug removal experiments were carried out in the presence of sodium borhydride (NaBH4) whic was used as a reducing agent and the degradation times of ARS and KET were monitored by UV-Vis Spectrophotometer (UV-Vis). The effects of parameters such as contact time, pH, NaBH4 concentration, nanocomposite dosage, drug and dye concentration on drug and dye removal were evaluated and the most suitable removal conditions were determined. As a result of the experiments, it was determined that ARS dye was removed by 85% in 50 minutes with g-C3N4@ZIF-8 nanocomposite and by 100% in 20 minutes with g-C3N4@ZIF-9 nanocomposite. It was determined that KET could be removed by 100% in 15 minutes with g-C3N4@ZIF-8 and by 30 minutes with g-C3N4@ZIF-9. The kinetic parameters (k) of the degradation reactions were calculated and it was confirmed by High Performance Liquid Chromatography (HPLC) analyses performed after catalytic degradation that ARS dye and KET reacted and degraded. The effectiveness of the obtained nanocomposites in the removal of organic compounds such as ARS and KET, which are environmental pollutants, was evaluated. It was observed that the synthesized nanocomposites permanently reduced organic pollutants in a short time and at a rate close to 100% under the most suitable experimental conditions