Preparation And Photocatalytic Performance Of Layered Double Hydroxides

With the rapid development of pharmaceutical,medical and aquaculture industries,antibiotic residues in wastewater are increasingly complex,which increases the difficulty of wastewater treatment virtually,and poses a threat to human health and aquatic ecological environment.Based on this,Co Fe-LDHs and Co Fe Ni-LDHs were synthesized respectively,the structure-activity relationship between catalyst structure,morphology and photocatalytic degradation of tetracycline hydrochloride was explored.The main influencing factors,dominant active substances and photocatalytic mechanism in the photocatalytic process were revealed.A new sewage treatment method for green and efficient photocatalytic degradation of tetracycline hydrochloride residue was established.The specific research content is as follows:Two layered double hydroxides were synthesized by hydrothermal method in order to explore photocatalysts that can degrade antibiotics efficiently.The surface morphology,structure and physicochemical properties of Co Fe-LDHs and Co Fe Ni-LDHs were investigated by various characterization methods.The generation,migration and transformation of active substances in the photocatalytic process were explored.The kinetic process of adsorption and photocatalytic degradation of tetracycline hydrochloride by the catalyst system were established.The activity and stability of the two LDHs were studied.A new sewage treatment method for green and efficient photocatalytic degradation of tetracycline hydrochloride residues was established.The experimental results show that the two photocatalysts can carry out efficient and stable degradation of tetracycline hydrochloride.On this basis,the effects of different metal proportions,catalyst dosage,initial solution concentration,p H value and other factors are explored.The optimal conditions for photocatalytic degradation of tetracycline hydrochloride by the two materials are determined.It was found that Fe²⁺and humic acid promoted the photocatalytic reaction,Cl^-and Ca²⁺inhibited the photocatalytic reaction,and SO₄^2-had little effect on the photocatalytic reaction.Recycling experiments show that the photocatalyst has good stability.In addition,the active substances in the degradation process were explored and the degradation pathways were analyzed.Quenching experiment and EPR show that h⁺and·OH play a dominant role.Compared with binary materials,ternary LDHs improves the separation efficiency of e^-and h⁺due to the cycling of Ni²⁺and Ni³⁺,thus promoting the photocatalytic performance.The photocatalyst synthesized in this paper showed high photocatalytic activity against tetracycline hydrochloride,which provided a new potential solution for the treatment of antibiotic wastewater.