For a long period, studies on the dissolution process of different metals have been among the most crucial topics consuming the minds of corrosion scientists and engineers. The data in this field has been constantly updated with growing industrialization and environmental pollution. Due to their exceptional corrosion resistance, which is collective by several additional needed properties such outstanding thermal and electrical conductivity, simplicity of processing and going to join, a broad variety of material properties, and coolants opposition, material and its alloys have a variety of uses and are thus used in a varied scenario. While many synthetic chemicals have corrosion-resistant qualities, most of them are quite detrimental to human strength and the environment. Many researchers and scientists underline the need of generate low-cost, harmless, and ecologically friendly organic reducing agents due of the acknowledged hazards of most synthetic organic defenders as well as strict environmental constraints. This work explores the green corrosion inhibition efficiency of Solanum Torvum Leaf extract (STL) for mild steel in 1.0 N HCl medium. At 1000 ppm, the extract achieved maximum efficiencies of 79.77% (weight loss at 333 K), 80.13% (polarization), and 77.32% (EIS). The corrosion rate decreased from 173.29 to 44.08 mmpy at 303 K and from 190.26 to 38.49 mmpy at 333 K, confirming strong protective action. Thermodynamic analysis showed activation energies of 64–68 kJ/mol and ΔG°ads values around –20 kJ/mol, indicating spontaneous mixed physical–chemical adsorption. Electrochemical studies revealed a reduction of corrosion current density from 4565 to 907 µA/cm2 and an increase in charge transfer resistance from 5.30 to 23.40 Ω·cm2. SEM, UV, FTIR, and EDX confirmed the formation of a protective inhibitor film. STL extract is thus established as an eco-friendly and effective green inhibitor for mild steel in acidic media.
SanaeiZRamezanzadehMBahlakehG, et al. Use of Rosa canina fruit extract as a green corrosion inhibitor for mild steel in 1 M HCl solution: a complementary experimental, molecular dynamics and quantum mechanics investigation. J Ind Eng Chem2019; 69: 18–31.
3.
BengoughCDStuartJM.The theory of metallic corrosion in the light of quantitative measurements. J Inst Metals1922; 28: 31.
4.
BahlakehGRamezanzadehBDehghaniA, et al. Novel cost-effective and high-performance green inhibitor based on aqueous Peganum harmala seed extract for mild steel corrosion in HCl solution: detailed experimental and electronic/atomic level computational explorations. J Mol Liq2019; 283: 174–195.
5.
BelghitiMEMihitMMahsouneA, et al. Studies of inhibition effect “E & Z” configurations of hydrazine derivatives on mild steel surface in phosphoiric acid. J Mater Res Technol2019; 8: 6336–6353.
6.
RanBQiangYLiuX, et al. Excellent performance of amoxicillin and potassium iodide as hybrid corrosion inhibitor for mild steel in HCl environment: adsorption characteristics and mechanism insight. J Mater Res Technol2024; 29: 5402–5411.
7.
QiangYGuoLLiH, et al. Fabrication of environmentally friendly losartan potassium film for corrosion inhibition of mild steel in HCl medium. Chem Eng J2021; 406: 126863.
8.
MamuduUAlnarabijiMSLimRC.Adsorption isotherm and molecular modeling of phytoconstituents from Dillenia suffruticosa leaves for corrosion inhibition of mild steel in 1.0 M hydrochloric acid solution. Results Surf Interf2023; 13: 100145.
9.
EashwarMSubramanianGChandrasekaranP, et al. Mechanism for barnacle-induced crevice corrosion in stainless steel. Corrosion1992; 48(7): 608–612.
10.
SalimRNahléAEl-HajjajiF, et al. Experimental, density functional theory and dynamic molecular studies of imidazopyridine derivatives as corrosion inhibitors for mild steel in hydrochloric acid. Surf Eng Appl Electrochem2021; 57: 233–254.
11.
SivaranjanaPRamasundaramSOhTH, et al. Enhanced anti-corrosion characteristics of epoxy-functionalized graphene oxide nanocomposite coatings on mild steel substrates. J Mater Res Technol2024; 32: 3234–3245.
12.
QiuRLiJCuiL, et al. Characterization of resistance spot welded joint between aluminum alloy and mild steel with compound electrodes. Trans China Weld Inst2017; 38(9): 47e50.
13.
DeivanayagamPMalarvizhiISelvarajS, et al. Corrosion behavior of Sauropus androgynus leaves(SAL) on mild steel in natural sea water. Int J Adv Pharm Biol Chem2015; 4(2): 574–583.
14.
EnoEAUmorenSA.Vernonia amygdalina leaf extract as green corrosion inhibitor for mild steel in HCl: gravimetric and SEM studies. Egypt J Pet2018; 27(2): 209–217.
15.
SanjaySKMudhooAJainG, et al. Inhibitory effects of Ocimum tenuiflorum (Tulsi)on the corrosion of Zinc in Sulphuric acid: a green approach. Rasayan J Chem2009; 2(2): 332–339.
16.
PetchiammalASelvarajSKalirajanK.Influence of Hibiscus Esculenta leaves on the corrosion of stainless steel in acid medium. Inter J Univ Pharm Bio Sci2013; 2: 242–252.
17.
SribharathyaVRajendranSSathiyabamaJ.Inhibitory action of Phyllanthus amarus extracts on the corrosion 2-thiophene carboxaldehyde as corrosion inhibitor for zinc in phosphoric acid solution of mild steel in seawater. Chem Sci Trans2013; 2: 315–321.
18.
OstovariAHoseiniehSMPeikariM, et al. Corrosion inhibition of mild steel in 1M HCl solution by henna extract, A comparative study of the inhibition by henna and its constituents (lawsone, gallic acid, α-d-glucose and tannic acid). Corros Sci2009; 51(9): 1935–1949.
19.
AbiolaOKOforkaNCEbensoEE, et al. Eco-friendly corrosion inhibitors: the inhibitive action of Delonix Regia extract for the corrosion of aluminium in acidic media. Anti Corros Methods Mater2007; 54(4): 219–224.
20.
PourhashemSVaeziMRRashidiA, et al. Distinctive roles of silane coupling agents on the corrosion inhibition performance of graphene oxide in epoxy coatings. Prog Org Coat2017; 111: 47–56.
21.
KucharskaBNitkiewiczZStachuraS, et al. All Polish corrosion. In: Conference materials and environments, Czestochowa, Poland, 22–25 June, 1999, Ochr. PizedKoroz: 1999, Special Issue: Korozja ‘99, 43–37.
22.
BoutouilALaamariMRElazharyI, et al. Towards a deeper understanding of the inhibition mechanism of a new 1,2,3-triazole derivative for mild steel corrosion in the hydrochloric acid solution using coupled experimental and theoretical methods. Mater Chem Phys2020; 241: 122420.
23.
Abdel HameedRSQureshiMTDinaM, et al. Application of solid waste for corrosion inhibition of steel in different media–A review. Int J Corrosion Scale Inhib2021;10(1):68–79
24.
ThangavelERamasundaramSPitchaimuthuS, et al. Structural and tribological characteristics of poly(vinylidene fluoride)/functionalized graphene oxide nanocomposite thin films. Compos Sci Technol2014; 90: 187–192.
25.
SobhiMAbdallahMEl-SayedR.The effect of nonionic surfactants containing triazole, thiazole and oxadiazole as inhibitors of the corrosion of carbon steel in 1 M hydrochloric acid. J Surf Deterg2013; 16(6): 937–946.
26.
KiniUAShettyANShettySD. Corrosion inhibition of Al6061-SiCp composite in the presence of 0.5 M HCl solution. In: Proceedings of the International Conference on Chemistry and Chemical Process (ICCCP 2011), 2011, vol. 10, pp. 168–172.
27.
SolehudinA.Performance of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide. Int Refereed J Eng Sci2012; 1: 21–26.
28.
BrightA.Solanum torvum fruits extract as an eco-friendly inhibitor on copper in acid medium. Res J Chem Sci2015; 5(11): 1–6.
29.
TanBRenHLiuY, et al. Insight into the anti-corrosion performance of crop waste as a degradable corrosion inhibitor for copper in sulfuric acid medium. Ind Crops Prod2024; 222: 119654.
30.
TanBRenHZhangR, et al. A novel corrosion inhibitor for copper in sulfuric acid media: complexation of iodide ions with Benincasa Hispida leaf extract. Colloids Surf A Physicochem Eng Asp2025; 705: 135710.
31.
VargheseJKumarMRajendranS.Comparative evaluation of green inhibitors for mild steel in acidic media using electrochemical methods. Arab J Chem2021; 14(7): 103216.
32.
AlabaAPOgundipeKA.Temperature-dependent inhibition of mild steel corrosion using Solanum torvum extract in HCl solution. Egypt J Pet2022; 31(2): 87–95.
33.
JohnsonASSethuramanMG.Inhibition of mild steel corrosion by Solanum torvum extract in hydrochloric acid. Mater Today Proc2020; 33: 3928–3932.
34.
NirmalaR. Enhanced inhibition of mild steel in HCl using hybridized Solanum torvum-zeolite systems: SEM, XPS and EIS studies. J Mol Struct2024; 1290: 136946.
35.
FathimaAPrakashMJ.Machine learning-assisted optimization of natural corrosion inhibitors from Solanum Torvum. J Clean Prod2025; 416: 139721.
36.
Abdel-GaberAMRahalHTBeqaiFT.Eucalyptus leaf extract as a eco-friendly corrosion inhibitor for mild steel in sulfuric and phosphoric acid solutions. Int J Ind Chem2020; 11(2): 123–132.
37.
RahalHTAbdel-GaberAMEl KhatibLW, et al. Evaluation of Fragaria ananassa and Cucurbita pepo L Leaf Extracts as natural green corrosion inhibitors for copper in 0.5 M hydrochloric acid solution. Int J Corrosion Scale Inhib2023; 12(4): 1417–1440.
38.
SolankiASSharmaASharmaS, et al. Mechanistic investigation of mild steel corrosion inhibition by Codiaeum variegatum extract: weight loss, EIS, and DFT perspectives. RSC Adv2025; 15: 24202–24222.
39.
RashidASRAslSKAsgharzadehH, et al. Investigation of the corrosion inhibition of X42 carbon steel in CO2-saturated brine using phaseolus vulgaris L. Bean Extract. Int J Electrochem Sci2025; 20(11): 101210.
40.
Prathap SinghSSuresh KumarSElil RajaD, et al. Machinability studies on AASiCTIO2 based heat treated HMMC with negative polarity electrode using EDM. Int J Interact Des Manuf 2024; 18: 5165–5176. https://doi.org/10.1007/s12008-023-01605-0.
41.
PandeyIUllasAVRastogiCK, et al. Extract preparation of waste lady finger caps using ethanol, generation of extract’s layers on copper through drop casting without and with NiO nanoparticles, and study of their corrosion performances in Saline Water. Waste Biomass Valorization2025; 16: 971–985.
