Preparation Of Metal Oxide Nanoparticles By Laser Ablation In Liquid

With the increasing demand for nanomaterials,the use of laser liquid ablation to prepare metal oxide nanoparticles has become a research focus in recent years.In this paper,nanosecond pulsed lasers were used to ablate targets in different solvents,and different kinds of metal oxide nanoparticles were successfully prepared and their morphologies were characterized.The main research contents are as follows:(1)The laser liquid ablation method was used to ablate metal Cu targets in H₂O,H₂O₂and Na OH solutions and successfully prepared Cu O nanoparticles.The effects of laser energy,ablation time and solvent types on the morphology of nanoparticles were explored.SEM(Scanning Electron Microscope)and TEM(Transmission Electron Microscope)characterization proved that increasing the laser energy and prolonging the ablation time can reduce the particle size of Cu O nanoparticles and weaken their agglomeration.When other conditions are the same,the Cu O particles in the Na OH solution are needle-shaped,while in the H₂O and H₂O₂ solution are elliptical,and the Cu O nanoparticles in the three solvents have serious agglomeration.Based on the related literature,the formation mechanism of Cu O nanoparticles was preliminarily discussed.(2)Using Mn O₂ as the target material,and then using the H₂O,H₂O₂ and Na OH solution as the solvent respectively,nanosecond pulsed laser was used to ablate the target material,and the influence of ablation time and laser energy on the morphology of nanoparticles was explored.The results of the study revealed that spherical nanoparticles were successfully prepared in three solvents,pure Mn O particles prepared in H₂O₂ and Na OH solutions,and a mixture of Mn O and Mn₃O₄ prepared in H₂O.Through TEM characterization,it is found that increasing laser energy can reduce the particle size.When the ablation time increases from 30 min to 90 min,the number of particles with particle size around 100 nm in the solution decreases obviously.Most particle sizes remain below 100 nm.(3)The laser liquid ablation method was used to ablate Cr₂O₃ targets in H₂O,H₂O₂ and Na OH solutions.Nano-sized Cr₂O₃particles were successfully prepared in the three solutions.The control of laser energy and ablation time was explored.Its influence on the morphology of nanoparticles.Studies have found that the type of solvent will not affect the composition of the nanoparticles,and increasing the laser energy and increasing the ablation time will reduce the particle size and improve its dispersion.When the ablation time increases from 30 min to 90min,the particles with a particle size of about 50 nm in the solution almost all change to particles with a particle size below 20 nm.