Eco-friendly food spice 2-Furfurylthio-3-methylpyrazine as an excellent inhibitor for copper corrosion in sulfuric acid medium

In this work, we studied food flavor 2-Furfurylthio-3-methylpyrazine (FFM) as the green inhibitor for copper corrosion H2SO4 solution. Electrochemical experiment data show that FFM can exhibit prominent anti-corrosion nature for copper in H2SO4 medium in the temperature range of 298 K to 313 K. Potentiodynamic polarization curve results show that the corrosion inhibition efficiency of FFM can be as high as 97.9% at a concentration of 5 mmol/L. The surface morphology test results show that adding 5 mmol/L FFM in H2SO4 medium, the copper sample is still relatively flat after soaking for 20 h, and the roughness values is only 7.84 nm. The XPS experimental results show that the S and N atoms in the FFM molecule can form N Cu and S Cu bonds on the copper surface to generate chemical adsorption. Besides, the FFM adsorption on the copper/solution surface conforms to the Langmuir monolayer adsorption model. The theoretical calculation results also prove that FFM can exhibit prominent anti-corrosion nature for copper in sulfuric acid medium.