Pyracantha fortuneana alcohol extracts as biodegradable corrosion inhibitors for copper in H2SO4 media

Compared with traditional copper corrosion inhibitors, Pyracantha fortuneana alcohol extracts are derived from natural plants, will not cause environmental pollution after use, and are in line with the concepts of green chemistry and sustainable development. In this study, Pyracantha fortuneana alcohol extracts (PFAE) were obtained by ethanol soaking extraction method. PFAE, a novel degradable green corrosion inhibitor, has been investigated by experiments and theoretical calculations for its anti-corrosion performance of copper in H2SO4 solution. Electrochemical experiments have demonstrated a pronounced increase in corrosion inhibition efficiency (η) as the concentration of PFAE rises. At a PFAE concentration of 600 mg/L, the inhibition efficiency can exceed 95 %. Additionally, the electrochemical method was used to investigate how the effect of soaked time on its anti-corrosion performance. After 4 h of immersion in a H2SO4 solution containing PFAE, the copper could still maintain more than 80 % of the anti-corrosion performance. The results of surface morphology analysis demonstrate that after adding PFAE, the roughness of the copper sample is significantly reduced. This provides intuitively evidence that PFAE can indeed proficiently inhibit copper corrosion within a sulfuric acid solution. According to the study of the adsorption model, it was found that the adsorption behavior of PFAE onto the copper surface adheres to the Langmuir monolayer adsorption model. Moreover, the findings indicate the coexistence of both physical and chemical adsorption mechanisms. The findings of molecular dynamics simulations (MD) and quantum chemistry (QC) calculations indicate that the six active components of PFAE can display strong anti-corrosion capability.