Study On Preparation And Photocatalytic Performance Of Modified Graphite Carbon Nitride

Energy and water resources have always been the focus of global conflicts.Due to the acceleration of modernization,it will inevitably cause damage to the natural environment.In particular,many industrial wastewater discharged into the water area without any treatment has caused serious pollution of the water environment.For this reason,many scientific researchers have tried a large number of methods.Among them,the use of semiconductor materials for environmental remediation under sunlight is undoubtedly a green and promising method.Graphite-phase carbon nitride as a photocatalyst that can be activated under visible light has recently attracted a lot of attention,but due to its own shortcomings,its effect in practical applications is not satisfactory.This topic takes graphite phase carbon nitride(g-C3N4)as the research object,and modifies it to have better catalytic performance through doping,defect and morphology control.The specific research is as follows:(1)Co-doped g-C3N4 was successfully prepared by solid-phase mixing of cobalt nitrate and melamine,and then by thermal decomposition method.The doping of cobalt broadens the light absorption range of graphite phase carbon nitride,and can also adjust the width of the band gap to enhance the photocatalytic activity.At the same time,cobalt can also activate PMS well.By combining advanced oxidation and photocatalysis,the Co-doped g-C3N4 degrades the RhB solution by 98%within 10 minutes.(2)After soaking melamine in a nitric acid solution,and then hydrothermally centrifuged for 12 h,the melamine obtained after drying is calcined to obtain a series of modified samples.Compared with pure g-C3N4,the modified g-C3N4 has a narrower band gap and stronger visible light absorption capacity.The modified g-C3N4 sample with the best catalytic effect can degrade up to 97%in the rhodamine B aqueous solution within 20 min under visible light.Under the same conditions,the degradation rate of pure g-C3N4 is only 23%.In the SEM image,it can be clearly seen that the carbon nitride has gradually changed from an irregular block shape to a rod shape.(3)Using glucose as the precursor,morphology control and carbon doping are carried out on the basis of nitrogen-vacancy rod-shaped g-C3N4.After SEM inspection,it is found that the newly prepared sample has a large number of holes on the surface and has a larger specific surface area.By degrading the RhB solution as a comparison,it can be found that the carbon-doped porous rod-shaped g-C3N4 degrades pollutants faster than other samples.At the same time,the degradation of different pollutants of the photocatalyst and the cycling experiment were carried out.The experimental results show that the prepared C-doped porous rod-shaped g-C3N4 has universal applicability and excellent structural stability.Figure 33 Table 6 Reference 98...