Study On Photocatalytic Removal Of NO And Plasma Nitrogen Fixation By Carbon Quantum Dots

NOx mainly comes from human activities,and is serious harmful for the environment and human health.Photocatalytic oxidation denitration technology is one of the most promising denitration technologies with advantages such as clean and low cost.At the same time,in order to meet the needs of agricultural production,plasma nitrogen fixation is used to fix nitrogen because a lower energy input theoretically.In this paper,carbon-based quantum dots?CQDs,S-CQDs?are doped on different semiconductors and metal organic framework?MOFs?,and their performances of photocatalytic denitration and plasma nitrogen fixation are studied.The main results are as follows:?1?Carbon-based quantum dots with good water solubility are prepared by electrochemical oxidation.Pure CQDs were compounded with P25 and MIL-100?Fe?,respectively.Under the conditions,the power of the xenon lamp is 160W,the temperature of the water bath is 25°C,and the initial concentration of NO is 10ppm,the doping of CQDs improves the NO removal performance of the two materials.The photocatalytic denitration efficiency of CQDs/P25 and CQDs/MIL-100?Fe?are 71%,and 70%,respectively.?2?The results of SEM and XRD indicate that the doping of carbon quantum dots will hinder the formation of anatase Ti O₂ particles,but has little effect on the crystal structure of MIL-100?Fe?.The PL and DRS characterization results confirm that CQDs improve the photocatalytic removal performance of the two materials due to three factors:broadening the light absorption range,improving charge transfer,and inhibiting electron-hole pairs recombination.?3?Single-unit-cell Bi₂WO₆?SUC-Bi₂WO₆?was obtained by intercalation with sodium lauryl sulfate?SDS?,and then S-CQDs were compounded with it to obtain composite material S-CQDs/SUC-Bi₂WO₆?SUSB?.The best performance is 90ppm.Characterization results of SEM and XRD showed that the appropriate amount of S-CQDs contributed to the crystallization of SUC-Bi₂WO₆,and the FTIR pattern confirmed the SDS intercalation and the loading of S-CQDs.In summary,it is speculated that the mechanism is that O atoms exposed and improved electron migration of S-CQDs will improve synthesis of NO.Some experiment and characterization results show that carbon-based quantum dots have good application prospects in photocatalytic denitration and non-thermal plasma nitrogen fixation.