5-Mercapto-1-phenyltetrazole as a high-efficiency corrosion inhibitor for Q235 steel in acidic environment

The corrosion inhibition performance of 5-Mercapto-1-phenyltetrazole (MPT) has been studied using theoretical calculation and abundant experimental methods. Electrochemical experiments show that MPT show high-efficiency corrosion inhibition ability for Q235 steel in H2SO4 environment. The concentration of MPT is 5 mM, the anti-corrosion inhibition efficiency (η) is 98.1% at the 298 K. Besides, the anti-corrosion nature of MPT can keep about 98% in the temperature district of 298 K to 318 K. The test results of atomic force microscope (AFM) and scanning electron microscope (SEM) strongly prove that MPT can effectively adsorb at the Q235 steel interface, thereby effectively inhibiting the Q235 steel corrosion. The adsorption of MPT at the interface of Q235 steel conforms to Langmuir single-deck adsorption, and both physical and chemical adsorption exist. The theoretically calculated surface MPT has a large dipole moment and a small energy gap value, so it can exhibit high-quality corrosion inhibition performance. [Display omitted] •Electrochemical data indicate MPT belong to the mixed-type inhibitor.•Surface characteristics analysis provided that MPT exhibit outstanding anti-corrosion nature.•MPT adsorb on the Q235 steel surface in accordance with the Langmuir model.•Theoretical calculation data show that MPT can exhibit good anti-corrosion performance.