Modification Of Graphite-phase Carbon Nitride And Its Degradation Of Organic Pollutants In Environment

With the development of social economy and people's lives,people's health has become the most concern in our life.However,with the growing new pollutants in the water environment,it threatens the people's health,especially the persistent organic pollutant in environment.Therefore,develop a green and efficient technical to solve the environmental problems has become one of most urgent task for researchers.Solar energy is clean energy and it has huge potential;photocatalytic technology could efficient conversion of solar energy and storage,controlled drive important chemical reactions under conventional condition?organic pollutants decomposition and mineralization,water splitting to hydrogen,photoinduced bacterial inactivation,etc.?.This has great advantages in solving environmental pollution and energy shortage.In the other hand photocatalysis decompose the persistent organic pollutant in environment also is important applications of photocatalysis technology.Due to their wide bandgap traditional photocatalytic materials have low utilization rate of solar energ.Graphite carbon nitride?g-C₃N₄?is a rich electron organic semiconductor;with the energy gap of 2.7 eV.As a nonmetal photocatalyst g-C₃N₄ could catalytic hydrogen evolution and oxygen evolution under ultraviolet and visible light.The g-C₃N₄ could remain molecular stability in acid corrosion,alkali corrosion and liht corrosion,the g-C₃N₄ with easy-control structure and easy to improve performance.In summary,g-C₃N₄ could be widely used in the application of photodegradation of organic pollutants.But pure g-C₃N₄ exist some natural defects,the band gap of 2.7 eV can only respond to sunlight that wavelength less than450 nm,photogenic electrons are easy to compound in photocatalytic process,can not expose catalytic.In this paper,we mainly aimed at the deficiency of g-C₃N₄,used doping,hybridization and morphology control to improving the g-C₃N₄.And characteristics of photoelectric properties and morphology to prepared materials,explores the application potential of catalyst in photocatalytic degradation efficiency of persistent organic pollutants and to explore materis other applications in the environment.The main contents of this study are as follows:?1?Modified the synthesis method of block g-C₃N₄,porous phosphorus doped g-C₃N₄?P-CN?was successfully prepared by simple forgiveness changes and the addition of phosphorus elements.A series of methods were used to characterize the prepared materials and degradation of rhodamine B?a common organic dye in the environment?under visible light.Experimental results show that the prepared materials degradation rate of RhB is 18times than bulk g-C₃N₄ and 4 times than not doped phosphorus materials,in that Rh B initial concentration was 10ppm and catalyst concentration was 1g/L.?2?Further improve the g-C₃N,to hybridize the P-CN with another excellent performance of photocatalyst BiOI,to prepare different proportions of composite photocatalyst.A series of methods were used to characterize the prepared materials.Use the composite to degradation RhB under visible light.The results show the composite materials exhibit the strongest catalytic performance when the content of P-CN in composite materials is 6%.In the study of the active groups in the process of degradation,that yhe hydroxyl radical?·OH?and photogenic hole?h⁺?are the main active groups involved in the reaction.?3?On the basis of above research,attempt to improve the photocatalytic performance of the catalyst by controlled the photocatalyst morphology.Phosphorus-doped nitride carbon?Ns-P-CN?was obtained by using high-temperature interlayer oxidation technology.The synthesized Ns-P-CN can successfully degrade BPS under visible light.In the study of the active groups in the process of degradation,it was found that hydroxyl radical?·OH?and photogenic hole?h⁺?were the main active groups involved in the reaction,the dissolved oxygen in water also plays an important role in the process of degradation.