Study On The Preparation Of Graphene Laminated Composite Materials And The Treatment Of Uranyl Ions In Water

With the rapid economic development in the era,due to traditional non-renewable resources such as ore and coal will be depleting,mankind will face severe energy exhaustion in the near future.As far as we know,seawater area and volume accounted for more than 71%and 95%in the earth,respectively.There are a lot of oil and radioactive uranyl ion in seawater.If we could be using its enrichment and recovery,it will finding a new way out to give energy problems.With the continuous use of unclear energy,the environmental pollution harmful problems were brought and it will gradually become more and more obvious,especially the problem of radioactive pollution.Without improvement,the long-term development of human society will not be realized.As uranium mines continue to be mined,heavy metal pollution,such as arsenic,is also still present.It is difficult to completely remove the traditional method.Therefore,a new solution has been developed necessarily which it will remove uranyl and arsenic ions in water.This will not only help solve the problem of environmental pollution,but also help to alleviate the energy crisis.Therefore,this paper systematically studied the research and application of two kinds of g-C₃N₄/TiO₂ and g-C₃N₄/NH₂-MIL-125?Ti?composite semiconductor photocatalysts in the removal of photocatalytic reduction and recovery of uranyl ion energy.In this paper,cheap precursor calcination method which is used in the synthesis of urea of graphene layer g-C₃N₄ catalyst,then the solvent thermal synthesis Ti based materials which were spherical TiO₂ and massive NH₂-MIL-125?Ti?,respectively.And via weak force and covalent bonds create g-C₃N₄/TiO₂ and g-C₃N₄/NH₂-MIL-125?Ti?compound semiconductor photocatalysts.By means of the molecular,atomic and electronic structures were analyzed systematically the catalysts.Such as XRD,SEM,FT-IR,Raman and XPS.Under the several experiments,and the results showed that the photocatalysis of40 CNT catalysts were by designed,in the 20 ppm U?VI?and 20 ppm As?III?mixed solution system,the removal efficiency were 82.66%and 41.18%.When the concentration of As?III?increases,the removal rate of U?VI?decreases.At the same time,As?V?products increase with the increase of the concentration of As?III?,the influence of the competition between the two heavy metals is affected.Furthermore,through at different times XPS analysis,we confirm that photocatalytic U?VI?reduced to U?IV?and As?III?oxide to As?V?simultaneously.In addition,�O₂^-,�OH and h⁺has been proved by free radical quenching experiments in process of As?III?,while photogenic electrons are mainly used for U?VI?reduce to U?IV?.In addition,we have the design of CN composite catalysts,and the experimental data show that the adsorption effect of pure NH₂-MIL-125?Ti?materials on U?VI?is good.The maximum adsorption capacity is 243 mg/g,and the adsorption model conforms to the Langmuir model and the adsorption reaction process is the exothermic process.The results of Zeta potential test showed that the isoelectric point was 2.80,which could have a good adsorption reaction of uranyl ions in 3⁷.And using photoelectric performance tests such as UV-vis,PL,Mott-Schottky and Photocurrent.The results show that two kinds of compound semiconductor catalysts based on electronic light response ability,the light ability and optical properties,such as electron and hole recombination rate has carried on the systematic analysis of the heterojunction compound catalyst photocatalytic activity,respectively.In addition,by FT-IR and XPS analysis of catalysts before and after reaction,we confirm that the photocatalytic synchronous U?VI?reduce to U?IV?.At last,the above work illustrates the competition and synergistic relationship between adsorption and photocatalytic oxidation reduction.And It could open a new chapter for the practical wastewater treatment and energy conversion in the future.