| Abstract [eng] |
The dissertation presents the first preparation of P and N modified reduced graphene oxide (rGO) samples through thermal and hydrothermal reduction of graphene oxide (GO) using a mixture of malonic acid/P2O5 and the organic dye Bismarck brown (BB) additives. The impact of this mixture was investigated on the structural, morphological, and electrical properties of rGO, as well as the thermal decomposition kinetics of GO. Using the Borchardt-Daniels, Kissinger, and Ozawa models, it was found that this mixture decreases the GO reduction temperature to 125 °C and reduces both the thermal decomposition enthalpy and activation energy. Increasing the content of malonic acid (10 wt.%) and P2O5 mixture effectively restores the rGO sp² hybridization, increases the P elemental concentration, and enhances electrical conductivity. This modification also enabled the creation of a new non-metallic electrochemical platform characterized by a low LOD and relatively high sensitivity for dopamine detection. A systematic investigation of the impact of BB concentration on the structural and electrochemical properties of the final rGO compounds revealed that the N modified rGO samples are promising electrode materials for highly selective electrochemical detection of dopamine. Compared to previously developed non-metallic nitrogen modified graphene sensors, our proposed sensor exhibited significantly lower LOD, a wider linear concentration range, and greater sensitivity. |
