Studies On Synthesis Characterization And Photocatalytic Properties Of Graphitic Carbon Nitride And Its Composities

Graphite-like carbon nitride (g-C3N4), a novel metal-free direct bandgapsemiconductor with bandgap of ca.2.7eV. g-C3N4are considered as themost likely material to replace the application of carbon in the fields of material,because its stacking layer structures and sp2hybridization π conjugatedelectron band structure which is similar to carbon. It has attracted intensiveinterest for its promising applications in photocatalysis recently.In this article, several morphologies of g-C3N4and its composites weresuccessfully synthesized. The structure and morphology were researched byXRD, SEM, TEM, XPS, FTIR, DRS and the nitrogen adsorption-edesorptionmeasurements. The photocatalytic efficiency were studied byUV-vis spectrophotometer. The main conclusions are as following:(1) Graphite-like carbon nitride (g-C3N4) nanorod, microcone and porousg-C3N4quadruple prism have been synthesized using modifiedthermal polymerization, which improve the morphology of g-C3N4. Thephotocatalysts show much higher efficiency for degradation of Rhodamine B(RhB) than bulk g-C3N4under visible light irradiation. We deduce that thesurface area and the adsorption play an important role in the photocatalyticactivity of g-C3N4photocatalysts.(2)3D (porous) microgrid g-C3N4have been synthesized using melamineas precursor through adjusting the PH of reaction system. The photocatalystsincrease the photocatalytic efficiency under visible light irradiation. We deducethat the surface area and the unique structure play an important role in thephotocatalytic activity of g-C3N4photocatalysts. Their growth mechanisms were also be researched.(3) Porous g-C3N4and g-C3N4/ZnS nanorod nanocomposites weresuccessfully synthesized by a facile adsorption self-assembly method. Theporous g-C3N4has the high photocatalytic activity, based on this, adding asmall mount of ZnS nanorod can increase the photocatalytic activity of porousg-C3N4. We deduce that the efficient separation of the photogeneratedelectron-hole pairs and the high specific surface area of porous g-C3N4playimportant roles in the photocatalytic activity of the nanocomposites.(4) Graphene-like g-C3N4nanosheets(GCN)/Fe3O4Quantum dot(QDs)nanocomposites were successfully synthesized by a facile electrostaticself-assembly method. Characterization shows that the GCN is at least severalmicrometers in size. The GCN and GCN/Fe3O4nanocomposites all show highphotocatalytic activity. Among them, GCN-2wt%Fe3O4nanocomposites hadthe highest photocatalytic activity. We deduce that the efficient separation ofthe photogenerated electron-hole pairs and the high specific surface area ofGCN play important roles in the photocatalytic activity of the nanocomposites.In addition, the nanocomposites can loaded with model drug, which making it apotential candidate for photocatalysis and controlled magnetic targeted drugdelivery.