Honeysuckle extract as an environment-friendly corrosion inhibitor for copper in sulfuric acid medium

Corrosion protection of metals has been a key research field for researchers. Many researchers in the field of corrosion protection have devoted themselves to finding non-polluting corrosion inhibitors. A convenient and inexpensive method was used to extract honeysuckle using water as a solvent to obtain honeysuckle extract (HE). Here, we measured the anticorrosive effect of honeysuckle extract (HE) on Cu in 0.5 mol/L H2SO4 using various experimental methods and combined with a theoretical approach. The experimental results indicate that the maximum corrosion inhibition efficiency (eta) of HE for Cu was close to 90%, and the value of eta remained a steady state at different temperatures. The data fit revealed that HE is a hybrid corrosion inhibitor. The functional groups and chemical composition of HE as well as the surface of the HE-soaked copper samples were characterized by Fourier transform infrared spectroscopy (FTIR). X-ray photoelectron spectroscopy (XPS) is used to test the chemical state, chemical bonding, and other information on the copper surface. To observe the micromorphology of the acid-corroded Cu surface and the Cu surface under HE protection, Scanning Electron Microscope (SEM) was used. Atomic force microscopy (AFM) was used to compare and analyze three-dimensional morphological images and roughness information of Cu surfaces. Finally, quantum chemical calculations were used to perform theoretical calculations of the active ingredients in HE, using molecular dynamics simulations to model their adsorption behavior.