| In this study,Zn powder and homemade Zn@(ZnO/Ag)core-shell powder were used as raw materials,and Zn/ZnO(abbreviated as ZZ)coating and ZnO/Ag/Zn(abbreviated as ZAZ)composite coating,the effect of spraying power and spraying distance on the morphology and composition of the coating was studied.The coating was chemically modified with heptafluorodecyltrimethoxysilane(FAS-17)and dopamine,respectively.The wettability,corrosion resistance,photocatalytic performance and antibacterial activity of the two coatings were analyzed,and the following conclusions were obtained:(1)The effects of spraying power on the morphology,photocatalytic performance and hydrophobicity of ZZ coatings were experimentally studied,and the best process parameters were obtained.It was found that Zn powder can be violently evaporated in the plasma beam and deposited into nanometer ZnO.As the spraying power increases,the ZnO morphology on the coating surface gradually changes from nano-particles to nano-sheets,and then to sub-micron particles;in addition,In addition,the content of ZnO in the coating increased first and then decreased with the increase of spraying power.The ZZ3 coating with a spraying power of 24 k W has the highest ZnO content,reaching 28.32%.ZnO is tremella-like and has the best photocatalytic performance.It only takes 200 minutes to degrade the methyl orange solution by about 85%,with a rate constant of 9.37×10-3/min.It was found that ZZ3 also had the best hydrophobicity after FAS-17 modification on all ZZ coating surfaces,and the contact Angle and sliding Angle were 158.2°±2.8°and 2.8°±0.5°,respectively.The photocatalytic mechanism of the ZZ3 coating was analyzed by the free radical capture experiment.The results showed that the order of active oxygen species in photocatalytic degradation process from strong to weak is:h+>·O2->·OH.By electrochemical polarization method,it was found that the corrosion resistance of ZZ coating was related to the content of ZnO in the coating,and ZZ3 coating also had the best corrosion resistance.(2)Zn@(ZnO/Ag)core-shell powder was prepared by chemical replacement method,and ZAZ composite coating was prepared by using the core-shell powder.As the spraying power increases,the size of the ZnO nanoparticles in the coating decreases and the content gradually increases;in addition,shortening the spraying distance can further increase the ZnO content,but the ZnO particle size will also increase.The particle size of ZnO in the ZAZ-D coating with a spraying power of 31.5 k W and a distance of 100 mm was reduced to 30 nm,and the content reached 84.35%,and the content of Zn was reduced to 15.65%.The photocatalytic performance of the coating is the best.The degradation rate of methyl orange is as high as 87.5%when exposed to a metal halide lamp for 120 min,and the rate constant is 1.462×10-2/min,which is 1.56times higher than that of the ZZ3 coating.On the other hand,the DRs UV-vis study found that the band gap of the ZAZ-D coating is only 1.73 e V,indicating that the addition of Ag improved the absorption rate of the coating to visible light,which was also an important reason for the improvement of the photocatalytic performance of the coating.In addition,the ZAZ-D coating modified by FAS-17 has a contact Angle of158.16±1.5°and a rolling Angle of 1.25±0.38°,showing excellent superhydrophobic properties.(3)The antibacterial properties of the two coatings on E.coli and S.aureus were studied by using the inhibition zone and growth curve method.ZZ3 had inhibitory effect on S.aureus,but the inhibitory effect on E.coli was not obvious;ZAZ-D had obvious inhibitory effect on both kinds of bacteria,and the inhibition zone was larger than ZZ3.The antibacterial effect of the two coatings under light conditions is better than that of dark conditions.The minimum inhibitory concentration(MIC)of the two coatings for E.coli was 200?g/m L,and for S.aureus was 50?g/m L,but the minimum bactericidal concentration(MBC)of ZZ3 is higher than that of ZAZ-D.Finally,the surface of the coating was modified with dopamine and FAS-17.The results showed that the coating modified with dopamine had superhydrophilic properties,and its antibacterial properties were improved.The antibacterial properties of FAS-17 modified coating decreased.The PS-CVD method proposed in this study successfully prepared ZnO nano-composite coatings,which can provide a new idea for the efficient preparation of semiconductor nano-oxide coatings. |
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