Aminobenzoic acid functionalized graphene oxide as environment-friendly corrosion inhibitors for Q235 steel in HCl solution: experimental and DFT studies

Abstract

Purpose The purpose of this study is to provide effective and environmental-friendly corrosion inhibitors derived from graphene oxide for Q235 steel. Design/methodology/approach Nontoxic and environment-friendly 4-aminobenzoic acid was used to functionalize graphene oxide via amidation and diazotization. The obtained amidation 4-aminobenzoic acid functionalized graphene oxide (PAGO) and diazotization 4-aminobenzoic acid functionalized graphene oxide (PDGO) were characterized by FTIR, Raman and TEM, while the inhibition efficiencies were analyzed by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP). Furthermore, theoretical inhibition efficiencies were investigated by density functional theory (DFT) approach. Findings At a concentration of 40 ppm, the maximum inhibition efficiency of PAGO and PDGO were 97.90% and 96.72% in EIS measurement, respectively, which were in accordance with PDP data. Moreover, experimental results were supported by DFT-based quantum chemical calculation. Originality/value Environmental-friendly PAGO and PDGO were synthesized successfully. The synthetic inhibitors exhibited excellent inhibition efficiencies in EIS and PDP measurements. Furthermore, a computational study using DFT supported the trend that PAGO was better inhibitor than PDGO.

Thiol–ene Click Chemistry Synthesis of L-Cysteine-Grafted Graphene Oxide As a New Corrosion Inhibitor for Q235 Steel in Acidic Environment

“…From Figure , the IE values of the modified GO corrosion inhibitor including bis (2-aminoethyl) amine-modified GO (NAEP-GO), octanoate-functionalized GO (SO-GO), cyclodextrin-based-functionalized GO (CD-GO), dopamine-functionalized GO (PD-GO), L-proline nitrate-functionalized GO (IL-GO), diaminodecane-functionalized GO (DAD-GO), and diaminododecane-functionalized GO (DADD-GO) were lower than 90%. The 4-aminobenzonic acid-functionalized GO (PA-GO) and diazotization 4-aminobenzonic acid-functionalized GO (PD-GO) showed higher corrosion inhibition efficiencies with IE values up to 98% . However, a larger dosage with a PA-GO concentration close to 40 mg L –1 was required.…”

“…29−35 For example, 4-aminobenzoic acidfunctionalized GO have been prepared, and the IE value for Q235 steel in the acidic medium (1.0 M) was close to 98%. 33 Saleh et al reported that the IE value of sodium caprylatemodified GO for protecting CS in HCl aqueous solution (15 wt %) was up to 80%. 35 Haruna et al reported β-cyclodextrinmodified graphene oxide (CD-GO) exhibited good corrosion resistance against CS corrosion in HCl solution (1.0 M) with IE close to 81.17%.…”

“…Biological molecules with organic structures containing many heteroatom elements are reported with corrosion inhibition performances. − However, most biopolymers showed a moderate inhibition efficiency, and the dosage of these biopolymers was much high and the concentration was even as high as 2000 mg L –1 . Environment-friendly and nontoxic compounds like 4-aminobenzoic acid, sodium octanoate, and cyclodextrin were covalently attached on the GO to form environmental-friendly functionalized GO corrosion inhibitors. − For example, 4-aminobenzoic acid-functionalized GO have been prepared, and the IE value for Q235 steel in the acidic medium (1.0 M) was close to 98% . Saleh et al reported that the IE value of sodium caprylate-modified GO for protecting CS in HCl aqueous solution (15 wt %) was up to 80% .…”

Application of Modified Graphene Oxide in Corrosion Protection

“…The dynamic potential polarization curves showed the maximum inhibition efficiency of 96.45 % and 95.15 % for PAGO and PDGO, respectively, verifying the results of the EIS. PAGO and PDGO significantly hindered corrosion by adsorption on the steel surface [106] …”

“…PAGO and PDGO significantly hindered corrosion by adsorption on the steel surface. [106] There are few studies on using functionalized GO as a corrosion inhibitor in highly acidic (15 % HCl) solutions. In all the studies, toxic solvents such as DMF, toluene, and THF were used for GO functionalization.…”