One-step synthesis of carbon nitride composite materials and its photocatalytic degradation of organic pollutants
Photocatalysis technology is the most promising technology to solve energy shortage and control environmental pollution.Carbon nitride is favored in the industry as a new type of green pollution-free semiconductor material.However,pure carbon nitride has low quantum efficiency and high photo-gener-ated carrier recombination rate,which limits the photocatalytic performance under visible light irradia-tion.The frequently-used modification methods include noble metal modification,ion doping and hetero-structure construction.In this paper,melamine,potassium iodide,and bismuth nitrate pentahydrate are used as raw materials.The graphite phase carbon nitride(g-C3N4)is prepared by calcining melamine at a high temperature of 520 ℃.The n-n type g-C3N4/BiOI heterojunction photocatalyst was prepared by one-step co-precipitation method.The heterojunction interface greatly increases the separation efficiency of photogenerated carriers,resulting in better photocatalytic performance.Photodegradation of methyl orange(MO),methylene blue(MB)and Rhodamine B(RhB)showed that the catalyst with molar ratio of g-C3N4∶BiOI=1∶1 had the best photocatalytic activity.The degradation efficiency of MO,MB and RhB was almost 100％,98％and 80％,respectively.The apparent reaction rate constants were 385 times,24.3 times and 2.5 times of pure g-C3N4.
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维普
