Electrochemical, quantum chemical and SEM investigation of the inhibiting effect and mechanism of ciprofloxacin, norfloxacin and ofloxacin on the corrosion for mild steel in hydrochloric acid

Abstract

The inhibiting effect and mechanism of 1-cyclopropyl-6-fluoro-1,4-dihydro -4-oxo-7-(1-piperazinyl) -3-quinoline carboxylicacid(ciprofloxacin), 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid (norfloxacin) and (−)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7 H-pyrido(1,2,3-de)-1,4-benzoxazine-6 carboxylic acid (ofloxacin) on the corrosion of mild steel in 1 mol/L HCl have been studied using electrochemical method, quantum chemical method and SEM at 303 K. The potentiodynamic results showed that these compounds suppressed both cathodic and anodic processes of mild steel corrosion in 1 mol/L HCl. The impedance spectroscopy showed that R p values increased, and C dl values decreased with the rising of the working concentration. Quantum chemical calculation showed that there was a positive correlation between some inhibitors structure properties and the inhibitory efficiency. The inhibitors function through adsorption followed Langmuir isotherm, and chemisorption made more contribution to the adsorption of the inhibitors on the steel surface compared with physical adsorption. SEM analysis suggested that the metal had been protected from aggressive corrosion because of the addition of the inhibitors.inhibition, mild steel, polarization, electrochemical impedance spectroscopy, SEM

Corrosion inhibition and mechanism of mild steel in hydrochloric acid by ceftriaxone and amoxicillin

“…In turn, the inhibitors molecules could protonate in the acidic solution, the protonated inhibitor and water molecules would be attracted on the metal surface by physical action, then there was a possibility that the inhibitors and Fe atoms could interact though the empty orbital and the occupied orbital each other, and in part 3.6, this work showed some results about the interaction between them on the microlevel [25].…”

The inhibition effect of o-nitrophenol and Zn2+ system on corrosion of aluminium

“…It is widely applied in the analysis of corrosion inhibition performance and the interaction of corrosion inhibitors and interfaces [29]. The B3LYP functional was applied within the context of Gaussian 09 [30], using the 6-31+G(d,p) basis set. From quantum chemical study, the mechanism of corrosion, inhibitor adsorption on metal surfaces, and the merits of corrosion inhibitors can easily be studied.…”

“…In chemisorption, one of the reacting species acts as an electron donor and the other one act as an electron acceptor. The energy of the highest occupied molecular orbital (E HOMO ) measures the tendency towards the donation of electron by a molecule [30]. High values of E HOMO have a tendency of the molecule to donate electrons to appropriate acceptor molecules.…”

Protection of low-carbon steel in solutions of mineral acids by nitrogen-containing pharmaceutical agents of triphenylmethane series

“…According to electrochemical impedance spectroscopy (EIS) data, Cefatrexyl can inhibit iron corrosion in HClO 4 , H 2 SO 4 and H 3 PO 4 [22]. A few antibiotics, namely, Ciprofloxacin (I), Norfloxacin (II), Ofloxacin (III) [23] and Gatifloxacin (IV) [24]: efficiently hinder carbon steel corrosion in cold HCl solutions. It has been shown that a temperature (t) rise decreases the inhibitory properties of Gatifloxacin [24].…”