Designing a nanostructured Biginelli reaction-based dipodal receptor for effective corrosion control of mild steel in 1 M H2SO4

Abstract

A novel nanostructured dipodal receptor synthesized via a one pot Biginelli multicomponent reaction was successfully engineered into organic nanoparticles (ONPs) and evaluated as an efficient corrosion inhibitor for mild steel in 1 M H₂SO₄. The rational molecular design, incorporation of multiple electron donating heteroatoms (N and O) and conjugated π-system facilitate strong adsorption onto the steel surface and promote the formation of a compact protective film. Electrochemical and gravimetric analysis confirmed excellent inhibition performance, achieving efficiencies of 90.14% (weight loss), 91.36% (potentiodynamic polarization), and 97.50% (electrochemical impedance spectroscopy) at an optimal concentration of 20 mg L⁻¹. Polarisation studies demonstrated mixed type inhibition behaviour with predominant control over acid dissolution, while impedance results revealed a significant increase in charge transfer resistance and reduced double layer capacitance, strengthening the formation of an effective adsorption barrier. The superior inhibition efficiency at low concentration highlights the synergic effect of the dipodal architecture and nanoscale dimensions, offering a scalable and high-performance strategy for acid corrosion mitigation in industrial systems.