Preparation 2D Nanosheets Of Graphitic Carbon Nitride And Its Methanol Catalysis Performance Study

In my research, the B C3N4(bulk C3N4) have been synthesized by the pyrolysis condensation of precursors.C3N4 NS(C3N4 nanosheets) was prepared by ultrasonic separation method in liquid phase and ball milling stripping method,respectively. Further, we investigated and compared the C3N4 NS characteristics in various aspects.Novel Ni/ C3N4 NS/carbon paper composite electrode was successfully fabricated by cyclic voltammetry electrochemical deposition method. The morphology and crystal structure were characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD), energy dispersive X-ray(EDX).The electrocatalytic performance for DMFC of these electrode was analyzed by cyclic voltammetry and time current method.The main research contents and results are as follows:â‘ The B C3N4 have been synthesized by the pyrolysis condensation of melamine. We realized the exfoliation of bulk C3N4 by ultrasonic separation method in liquid phase method and ball milling peeling method, respectively. The crystal structure and morphology were characterized by SEM and XRD.We found that C3N4 NS which was prepared by ultrasonic separation method in liquid phase method has significant sheets like structure.It not only has large area, but also has a good performance in electron transformation. So, it is suitable as a catalyst carrier material.â‘¡ The preparation of Ni/ carbon paper and Ni/ C3N4 NS/ carbon paper electrode by two steps. Firstly, the B C3N4 powder and C3N4 NS powder were put in solution, then drop the solution to the carbon paper electrode and finally dried. This was a good method to determine the sample quality. Ni/ C3N4 NS/carbon paper electrode and Ni/ C3N4 NS/carbon paper composite electrode were successfully fabricated by cyclic voltammetry electrochemical deposition method. We tested the electrocatalytic properties for methanol oxidation.â‘¢Cyclic voltammetry(CV), time current curve and AC impedance(EIS) were taken on Ni/carbon paper electrodeand Ni/C3N4 NS/carbon paper electrode for methanol oxidation catalysts, respectively. The cyclic voltammetry results showed that, Ni/C3N4 NS/carbon paper electrode has excellent catalytic activity than Ni/ carbon paper electrode. The chronoamperometry results showed that methanol catalytic stability of Ni/ C3N4 NS/ carbon paper electrode is better. This was because the interaction between C3N4 NS and Ni metal and there was the transfer of electrons between them. The electron delocalization in the ring of C3N4 NS, When the Natom matched to nickel atom, the coordinated into new hybrid orbital. Meanwhile, it occurred electronic distribution so that the valence of nickel was been improved. Further, it could improve catalyst activity. N atom in C3N4 could improve the hydrophilic property and it was good at the adsorption and aggregation of methanol. Thereby it enhanced the local concentration of catalyst in methanol so that the catalytic activity were been increased.