The Synthesis Of Pyridine And Boron Doped G-C₃N₄ And Its Production Of Hydrogen Peroxide By Photocatalysis

As a promising way to solve the lack of energy and pollution of environment,semiconductor photocatalyst can transform the solar energy into electric energy or light energy.Among the various kinds of semiconductor,graphene phase carbon nitride（g-C₃N₄）was favored by researchers for its advantage of not containing metal element,cheap price,stable performance,eco-friendly properties and fitting width of band gap.However,suffering from the small specific surface area,charge carriers’high chance of combination and insufficient utilization of visible light,the application of g-C₃N₄ is highly restricted.In this paper,we focus on these problems above,aiming at how to design and synthesize high property photocatalyst.We dope pyridine ring and relevant atom into g-C₃N₄ by supermolecule self-assemble method in order to adjust the surface pattern,band gap construction and specific surface area so as to improve the performance of hydrogen peroxide production by photocatalysis.Our current work is below:（1）We used Melamine,cyanuric acid and pyridine-2-formaldehyde as precursors,ethanol as solvent.After synthesized the structure by self-assembly method,we calcined the sample at 550°C to prepare a series of different concentration of pyridine-doped carbon nitride（Py-x）.Compared with bulk carbon nitride（BCN）,the undoped carbon nitride nanorods（CNMR）have a higher specific surface area and better performance of photocatalysis.The results showed that the addition of pyridine ring can further expand its specific surface area,which led to a higher efficiency of the separation of charge carrier.When we add 5μL pyridine-2-formaldehyde into the system,the yield of hydrogen peroxide under the neutrality condition reached180μmol·g^-1·h^-1,which is 1.85 times higher than BCN.（2）We used Melamine,cyanuric acid,pyridine-2-formaldehyde and boron chloride as precursors,ethanol as solvent.After synthesized the structure by self-assembly method,we calcined the sample at 600°C to prepare a series of different concentration of pyridine/boron multidoped carbon nitride（Py-x/B-y）.Compared with bulk carbon nitride（BCN）,the undoped carbon nitride nanorods（CNMR）have a higher specific surface area and better performance of photocatalysis.What’s more,the addition of pyridine ring containing more delocalized electron and single atom boron which is lack of electron can form electron field inside the molecule.This led to a consequence of higher efficiency of the separation of charge carrier.When we add 5μL pyridine-2-formaldehyde and 10μL boron chloride into the system,the yield of hydrogen peroxide under the neutrality condition reached 391μmol·g^-1·h^-1,which is 2.18 times higher than Py-5,4 times higher than BCN.