Study On The Corrosion Inhibition Performance Of Copper Based On Sulfur-containing Organic Molecules In Sulfuric Acid Medium

As one of non-ferrous metals,copper has been widely used in human production and life.However,when serving in harsh environment,the copper manufacturing equipments will suffer different degrees of corrosion,which will cause extremely serious safety accidents and economic losses.Therefore,the research and development of high-efficiency and eco-friendly corrosion inhibitors is of great significance.In this paper,the electrochemical experimental methods,surface morphology analysis,quantum chemical calculations,and molecular dynamics simulations were used to deeply explore the corrosion inhibition performance of disulfide derivatives for copper in sulfuric acid at the molecular/atomic scale in this paper.In-depth analysis of corrosion inhibition mechanism has provided certain theoretical support for the development of new sulfur-containing corrosion inhibitors.The research contents of this paper are as follows:(1)Potentiodynamic polarization curve test,electrochemical impedance spectroscopy measurement,scanning electron microscope measurement and atomic force microscope test were used to explore the corrosion inhibition performance of disulfide derivatives containing different substituents(propyl disulfide,diallyl disulfide and dibenzyl disulfide)for copper in sulfuric acid corrosion medium.The test results show that propyl disulfide has the highest corrosion inhibition performance.Among them,propyl disulfide and dibenzyl disulfide are mixed-type inhibitors,and diallyl disulfide is a cathodic-type inhibitor.The results of surface topography measurement and electrochemical experiment data are in good agreement.Theoretical calculations insight into the active adsorption sites of propyl disulfide,diallyl disulfide and dibenzyl disulfide.The stable adsorption configurations of propyl disulfide,diallyl disulfide and dibenzyl disulfide on copper surface are forecasted by molecular dynamics simulations.The results of theoretical calculation and experimental test are consistent.(2)Electrochemical test ways,surface analysis were used to explore the anti-corrosion performance of mono-and di-sulfur food flavors(furfuryl mercaptan and difurfuryl disulfide)for copper in sulfuric acid medium.The experimental results show that difurfuryl disulfide with more adsorption sites has higher anti-corrosion performance.The adsorption of furfuryl mercaptan and difurfuryl disulfide onto the Cu surface conforms to the Langmuir single-layer adsorption model,and they are adsorbed on the copper surface via physical and chemical adsorption.X-ray photoelectron spectroscopy tests manifest that the sulfur atoms in furfuryl mercaptan and difurfuryl disulfide can form coordination bonds with the copper substrate.Quantum chemistry calculations show that difurfuryl disulfide has a smaller energy gap and larger dipole moment value than furfuryl mercaptan,which is beneficial the adsorption of difurfuryl disulfide on the copper surface.Molecular dynamics simulations show that difurfuryl disulfide has higher binding energy and greater coverage after adsorption on the copper surface,thus difurfuryl disulfide has higher corrosion inhibition performance.(3)Electrochemical methods,surface topography analysis,molecular dynamics simulation and quantum chemical calculations were used to insight into disulfide derivatives with different numbers of heteroatoms(phenyl disulfide,2,2-dithiodipyridine,5,5-dithiobis(1-phenyl-1H-tetrazole))on the anti-corrosion performance of copper in sulfuric acid medium.The experimental results show that5,5-dithiobis(1-phenyl-1H-tetrazole),which contains the largest number of heteroatoms,can exhibit the highest corrosion inhibition ability.Molecular dynamics simulation calculations show that the configuration of 5,5-dithiobis(1-phenyl-1H-tetrazole)after adsorption on the Cu(111)surface is more parallel and orderly,and the value of binding energy is larger than that of phenyl disulfide and 2,2-dithiodipyridine.Therefore,the theoretical calculation and experimental results are in agreement.(4)Electrochemical methods,surface morphology analysis,quantization calculations and molecular dynamics simulations were used to explore the corrosion inhibition performance of different functional group disulfide derivatives(2,2?-dithiosalicylic acid,2-aminophenyl disulfide and 2,2-dibenzamidodiphenyl disulfide)of copper in sulfuric acid medium.The experimental results show that2-aminophenyl disulfide and 2,2-dibenzamidodiphenyl disulfide containing electron-donating groups can exhibit better anti-corrosion performance than2,2?-dithiosalicylic acid containing electron-withdrawing groups.Polarization curve test shows that 2,2?-dithiosalicylic acid,2-aminophenyl disulfide and2,2-dibenzamidodiphenyl disulfide can simultaneously restrain the cathodic and anodic reactions of Cu electrode,they belongs to mixed-type inhibitors.The results of molecular dynamics simulation calculations match the results of electrochemical experiments.