Study On Structure Regulation And Antibiotic Degradation Of Molybdenum Disulfide Based Piezoelectric Materials

The widespread use of antibiotics has resulted in large amounts of drugs being released into sewage,and improper management can cause serious problems for humans and animals.Piezocatalysis is a new water purification method emerging in recent years.It is favored by researchers because it does not add chemicals,operates in dark room and has excellent degradability of organic matter.To improve the piezoelectric properties of transition metal sulfides molybdenum disulfide,molybdenum disulfide was modified by graphdiyne doping,increasing layer spacing and Ni doping.In addition,in view of the problems of low stability,difficult recovery and particle agglomeration of granular catalyst,the nano-catalyst was combined with polyvinylidene fluoride flexible polymer substrate and natural wood to form three-dimensional nanocomposite material,which realized efficient recovery of catalyst.Based on the synthesis of high efficiency piezoelectric catalyst,the mechanical force was provided by ultrasonic,ball milling,hydrodynamic force and other methods to further explore the possible forms of piezoelectric catalytic degradation.The main research results are as follows:（1）MoS₂/GDY-3 with a small amount of thin layer structure was synthesized by graphdiyne doped molybdenum disulfide.MoS₂/GDY-3 showed good piezoecatalytic activity,and the degradation rate of tetracycline was 92.15%after 40 min by ball milling.After 5 cycles,the degradation rate reached 87.15%,indicating good stability.The effects of MoS₂/GDY-3 dosage,milling speed,tetracycline concentration,p H,inorganic anion and water source on degradation efficiency were investigated.The possible degradation path of tetracycline was further analyzed through the analysis of intermediate products,and the suitable was proposed.The toxicity of intermediate products was evaluated to explore the toxicity changes during degradation.（2）A novel E-MoS₂/PVDF piezoelectric microcapsule with excellent piezoecatalytic performance was synthesized by coupling E-MoS₂ with PVDF.Using E-MoS₂/PVDF microcapsules as piezocatalyst,a bubble driven piezocatalytic degradation process of antibiotics was proposed.The results showed that the degradation efficiency of E-MoS₂/PVDF microcapsules for tetracycline,chloromycin and ofloxacin were91.88%,85.48%and 96.84%,respectively,within 60 min.After 5 cycles,the degradation rate of tetracycline still reached more than 73%.This bubble-driven piezocatalytic process(76.00 kwh^-3order^-1)has low energy consumption.（3）Growing MoS₂ on a natural wood containing porous cellulose and introducing a highly conductive circuit path provided by Ni nanoparticles,a novel piezoelectric three-dimensional wood block was constructed to efficiently degrade tetracycline.Ni/MoS₂/Wood showed excellent piezocatalytic degradation performance,and the degradation rate of tetracycline reached 95.96%under ultrasonic vibration.The degradation rate still reached 90.20%after 5 cycles.In addition,Ni/MoS₂/Wood was used as filler to degrade tetracycline by hydrodynamic triggering piezoelectric response,and the degradation rate reached 90.27%after 60 min.