Removal Of Organic Pollutants In Water By Metal-organic Frameworks/Cellulose Hybird Aerogels

Metal-organic framework materials?MOFs?are a new type of organic-inorganic hybrid porous nanomaterials,which have attracted much attention due to their wide application in the field of heterogeneous catalysis.In order to improve the characteristics of powdery and difficult to reuse,this paper proposes to combine it with porous cellulose aerogel to prepare MOFs/cellulose hybrid aerogels materials for water purification.Among them,cellulose is the most abundant resourse in nature,and cellulose aerogels has good biocompatibility and stable physical and chemical properties,and it is expected to produce multifunctional catalytic materials that conform to the green and environmental protection concept.The main synthetic concept of MOFs/cellulose hybird aerogels is that to use cellulose aerogels as carrier and to load the multifunctional MOFs into the pores of cellulose aerogels by in-situ synthesis and doping,and MOFs/cellulose hybird aerogels as green catalyst to activate potassium persulfate?PMS?which could generate strong oxidizing free radicals to degrade organic pollutants.In this paper,the crystal structure,morphology and loading rate of MOFs/cellulose hybird aerogels were systematically studied.Further,p-nitrophenol?PNP?and tetracycline hydrochloride?TC?were used as representatives to research its degradation performance.The effect of pH values,dosage of PMS,cycling number and preparation methods on degradation performance of MOFs/cellulose hybird aerogels was also studied.The related degradation mechanism of PNP and TC was explored by reviewing the related literature and experimental test.The results are listed as follows:?1?The ZIF-9@GEL and ZIF-12@GEL cellulose hybird aerogels with high porosity,high loading rate and high efficiency degradation were prepared by in-situ synthesis.The porosity of the two hybird aerogels was as high as 88.5%and 91.3%,respectively,and loading rate also reached 37.96wt%and 31.41wt%,respectively.ZIF-9@GEL and ZIF-12@GEL cellulose hybird aerogels also have excellent degradation properties,excellent removal performance for PNP and TC contaminants and have stable pH resistance and recycling performance.?2?The ZIF-67@GEL cellulose hybird aerogels with loading rate reached 44.6wt%was prepared by doping method,and the loading rate was further improved.The hybird aerogel also had more efficient degradation performance and the removal rate can reach 90%within 20 min,and its pH resistance and recycling performance are also stable;?3?While measuring the practical application possibility of cellulose hybird aerogels by recycling performance,it is also necessary to investigate the stability of its structure and properties.It is found that the crystal structure and appearance of the hybird aerogels is stable after use.It could be seen that all of the hybird aerogels have stable crystal structure and microscopic morphology.?4?To explore the mechanism of the hybird aerogels/PMS system for degrading organic pollutants in water:the effect of cellulose hybird aerogels as heterogeneous catalyst is mainly derived from the transition metal Co-containing MOFs attached to the pore walls of aerogels?ZIF-9,ZIF-12 and ZIF-67?,which can be used to catalyze the strong oxidizing of·OH and SO₄·–by potassium persulfate?PMS?.The organic pollutants are decomposed into non-toxic small molecules and even mineralized into CO₂ and H₂O.Through experiments,found that SO₄·–plays main role in the PNP degradation process.Whereas,·OH plays a minor role.And SO₄·–play entire role in the TC degradation process,the·OH cannot decompose the TC pollution.