Laser Induced Metal Micro/Nanostructure And Its Application In Water Environmental Protection

The water pollution problem has received a lot of people's attention,mainly in two aspects:first,the use value of water reduces or even loses due to the discharge of domestic and industrial wastes;second,the pollution from the transportation,handling,processing,and use of oils.During the interaction between laser and material,some of the material is removed,and the remaining material will form a certain micro/nanostructure on the surface.The removed material can be used for the preparation of metal nanoparticles,such as the preparation of TiO2 nanoparticles to purify water resources;at the same time,the remaining materials can be processed into three-dimensional structures,and copper with special wettability can be prepared which can be used to do water/oil separation.In this work,the study of laser induced micro/nano structures on some metals is carried out.The theory of a simple understanding of laser induced metal micro/nano structures,application of these materials in water environmental protection and its physical mechanism are discussed.It can be divided into the following parts:(1)Ag/TiO2 composite nanoparticles are fabricated by laser ablation in liquid(LAL),and the photocatalytic properties of nanoparticles are studied.The practical applications of TiO2 have been greatly limited due to its inherent defects.To solve this problem,the Ag nanoparticles are deposited on the TiO2 surface by LAL to fabricate the Ag/TiO2 composite nanoparticles,which effectively remedy the defects of TiO2.In the study,Ag/TiO2 is characterized by various means,and photocatalytic tests show that the prepared Ag/TiO2 has better performance than TiO2.(2)The copper mesh with superhydrophobic properties is fabricated by laser direct writing and chemical post-processing method.The relationship between surface morphology and hydrophobicity is studied by adjusting the experimental parameters.Then the oil/water separation experiments of the copper mesh are carried out.The results show that the prepared copper mesh can easily separate the oil/water mixture,and has good corrosion resistance and wear resistance.(3)The laser direct writing method is used to fabricate copper mesh with under-liquid superamphiphobicity,and the effect of copper mesh in oil/water mixture separation is also studied.Compared to the preparation of the hydrophobic copper mesh,the preparation of this copper mesh does not require chemical post-processing,the preparation process is more easy,can separate heavy oil and light oil at the same time,and will not be contaminated by oil.The relationship between surface morphology and oil/water separation performance is also studied in detail.