Preparation And Photocatalytic Properties Of Titania And G-C₃N₄ Complexes

Titanium dioxide is the most promising photocatalyst in the current study.However,the wide band gap of titanium dioxide allows it to absorb only ultraviolet light.Graphite carbon nitride?g-C₃N₄?has attracted much attention in recent years due to its potential application in photochemistry,and it is non-toxic,stable and easy to prepare.And its own narrow band gap also compensates for the defects of titanium dioxide.This paper focuses on the photocatalytic properties of graphite carbonitride?g-C₃N₄?and its composite with titanium dioxide.In this paper,titanium dioxide nanowires doped with different metals were prepared by molten salt method.The samples prepared by XRD showed rutile.The photocatalytic activity of the sample was evaluated by using methyl blue solution as the target degradation product.The titanium dioxide sample doped with Ag and Mn was irradiated by 250W mercury lamp.The degradation efficiency of methyl blue reached 61%after140min.The photocatalytic efficiency did not achieve the desired effect,so a composite of titanium dioxide and graphite phase carbonitride was prepared by using P25 as a precursor.Through the thermogravimetric analysis of melamine,the melamine heat polymerization temperature range is 300-380?/min,and the heating rate is changed in this interval?set to 1?/min,2?/min,5?/min,8?/min,10?/min?,graphite phase carbonitride carbon?g-C₃N₄?was prepared.The sample structure was analyzed by SEM,FT-IR,UV-Vis DRS,etc.The g-C₃N₄ sample was found to have a sheet structure ang its band gap was about 2.8 eV.Finally,the photocatalytic activity of the sample was evaluated by degrading methyl blue.It is concluded that the photocatalytic performance of the sample g-C₃N₄-8 prepared at a heating rate of 8?/min is superior to the other four groups of samples.The composite of titanium dioxide and graphite phase carbonitride was prepared from P25 and melamine at a heating rate of 8?/min,and TiO₂/g-C₃N₄ of different ratios were prepared by changing the proportion of melamine.?Melamine accounts for 40%,60%,80%,100%,120%of TiO₂,respectively.?,and the structural information of the sample was analyzed by XRD,TEM and FT-IR.The photocatalytic degradation of the complex was carried out with methyl blue as the target degradant.The optimum ratio of the composite was determined by analyzing the photocatalytic degradation efficiency,and it was finally determined that the photocatalytic performance of g-C₃N₄/TiO₂-120%in the composite sample was the best.