Anti-corrosion Nature Research Articles

Optimization of Zn-Cr proportions for hybrid multilayer electroplating of AISI 1045 steel – towards super-hydrophobicity and anti-corrosive nature

Localized corrosion in steel heat exchangers is a major concern, occurring mostly during operational shutdowns. Due to the absence of flow and moisture content availability, corrosion reduces operation efficiency. A study aimed to optimize the proportions of Zinc and Chromium (Zn-Cr) for developing a hybrid multi-layer electroplating method to inhibit corrosion in hypo-eutectoid carbon steel commonly used in heat exchangers. The Zn-Cr coating was performed using the amperometric method in an electrochemical workstation, producing coatings of varying thicknesses by varying the potential and time. The surface morphology was characterized using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analysis. The average thickness of the Zn-Cr coating was found to be 2.5 µm using the scanning probe microscope analysis. The corrosive action of a standard 3.5% NaCl solution was investigated on both coated and uncoated specimens through open circuit potential measurement and electrochemical impedance spectroscopy. The results indicated that the Zn-Cr coating effectively resisted corrosion. Contact angle measurement of water particles with the Zn-Cr coated specimen revealed a near-super hydrophobic nature with the highest contact angle of 146.8°.

Investigation of the corrosion inhibitory effectiveness of castor leaf extract as a corrosion inhibitor for steel in a sulfuric acid environment

The Castor Leaf Extract (CLE) was prepared using pure water as the solvent and was obtained through the decoction method. CLE exhibits outstanding anti-corrosion nature as an inhibitor in H2SO4 media for X70 pipeline steel. The electrochemical test has shown that the inhibition efficiency of CLE can be up to 92.8 %. CLE, a mixed-type corrosion inhibitor, is capable of inhibiting both cathodic and anodic processes in the X70 pipeline steel/H2SO4 system. The morphology of the X70 steel surface turns into significantly flatter and brighter with increasing CLE. The adsorption of CLE at the X70 steel/H2SO4 interface follows the Langmuir monolayer adsorption model, which encompasses both physical and chemical adsorption processes. Theoretical calculations demonstrate that CLE is able to effectively protect X70 steel from corrosion by H2SO4 solution.

High performance coating formulation using multifunctional monomers and reinforcing functional fillers for protecting metal substrate

Purpose Effects of corrosion are very dire and mitigation of corrosion holds prime importance. Protective coatings play major role in preventing corrosion of metals and coating application is the most convenient, economical and quick solution. The purpose of the study is development of protective coatings to effectively mitigate corrosion of metal components. Design/methodology/approach A high-performance anticorrosion coating was prepared using multiple monomers and paste of functional and reinforcing fillers with extenders to protect metal components from corrosion in aggressive environmental conditions. The structures of copolymers synthesized with multiple monomers were studied by the NMR and FT-IR spectroscopic techniques. The percentage conversion of different proportions of various monomers was estimated using gas chromatography technique. The functional paste to impart superior anticorrosion properties was prepared using various functional and reinforcing fillers. The final coatings were prepared by mixing these resins with functional paste in various proportions. Findings The prepared anticorrosion coating was tested for high-performance mechanical and chemical properties and it was witnessed that the said coating offered desired performance properties needed for protecting metal components from corrosion. Research limitations/implications As such it is overcoming drawbacks of two pack systems and thus has almost no limitations or implications for application on metal substrate. Practical implications Being formulated as a single pack, it is free from drawbacks otherwise involved in two pack system of conventional paints. The coating system developed is very easy to apply using conventional tools, namely, brush, spray and roller techniques. The formulation is made in such a way that it has fast-drying properties. Makes painting or coating operations cost effective and confirm the performance. Social implications The findings of the research have anticorrosion nature that can enhance the life span of the substrates. It is specially designed for metal substrate and can protect metal substrate from corrosion in most aggressive conditions. Thus, it helps to reduce losses due corrosion and increase safety of metal structures and human being as well. As it is based on conventional material but with new formulation and technology, it has commercial possibilities to explore. Originality/value Unlike conventional protective coating systems, the said coating offered disruptive features like single pack systems and fast drying at ambient temperature along with high-performance properties. The coating formulation was observed to have a great importance in industry for effective corrosion mitigation and to reduce losses due to corrosion.

Construction of Ag/CdZnS QDs nanocomposite for enhanced visible light photoinactivation of Staphylococcus aureus

With increasing use of antibiotics, the development of antibiotic-resistant pathogens poses a serious threat to human health and the environment. Photocatalytic inactivation of these harmful pathogens is one of the novel and non-antibiotic treatments. The study fabricated Ag NPs decorated CdZnS QDs via a facile and biological co-precipitation method using L. camara plant extract as a green alternative to treat the toxic chemicals. The fabricated Ag/CdZnS QDs (NCs) were prepared for the efficient treatment of antibiotic-resistant pathogens as they raise a major global concern. The fabricated NCs were characterized with various characterization techniques to verify its physicochemical properties. The fabricated NCs have shown excellent photo-sterilization performance of 97 % against S. aureus. The excellent activity was attributed to the decoration of Ag NPs on CdZnS QDs as it helped in shortening band gap, improved visible light absorption ability, increased active sites, and boosted photogenerated electron/hole pairs stability. Radical trapping experiment and ESR analysis indicated the involvement of •OH and h+ in the photoinactivation of bacteria. The photo sterilization reaction of NCs was carried out under different environmental conditions, including light and dark conditions and different pH conditions. The experiment was carried out in sewage-treated water in order to test the real-time application, and the fabricated NCs achieved excellent 95.9 % photo-inactivation of S. aureus cells in sewage treated water and the Chemical Oxygen Demand (COD) of the system was increased after photo inactivation treatment. The fabricated NCs have also shown excellent reusable efficiency of 95% after six runs and the photostability and anti-corrosive nature of NCs were confirmed. The study provides an insight for the employment of photocatalysis for the sterilization of pathogens in real time aquatic environment across the globe.

Computational Investigation of Corrosion Inhibition Properties of Hydrazine and Its Derived Molecules for Mild Steel

Corrosion of mild steel has gained a lot of attention by many industries and academia. This study was aimed to find the corrosion inhibition properties of hydrazine and its 11 derived molecules for mild steel using computational method, namely, the density functional theory with Beck 3‐parameter Lee Yang and Parr functional along with the 6‐311++G (d, p) basis set using simple quantum chemical parameters. The main quantum chemical parameters were energies of highest occupied and lowest unoccupied molecular orbitals and their energy gap, dipole moment, hardness, softness, electrophilicity index, the fractions of electrons transmitted, the change energy back‐donation, electron‐donating power, electron‐accepting power, molecular electrostatic potential, and Fukui function as well as polarizability. The results indicated that hydrazine derivatives have good anticorrosion nature which is consistent with the experimental findings. Out of the 12 target inhibitor molecules, N′‐(3‐nitrobenzylidene) hydrazine carbodithioic acid (NBHCA) and N′‐(4‐dimethylaminobenzylidene) hydrazine carbodithioic acid (DABHCA) are the most effective inhibitors. According to the value of the quantum chemical parameters, EHOMO, ΔEgap, Χ, η, σ, ε, ΔN, α, and ΔEb-d DABHCA showed the top effective anticorrosion inhibitor, and by the value of the quantum chemical parameters, ELUMO, TE, ω−, and ω+ NBHCA showed an effective anticorrosion inhibitor. The quantum chemical parameter data showed that NBHCA and DABHCA are nearly equivalent in their values, which is consistent with experimental values. Furthermore, a multiple‐linear regression equation was proposed as a quantitative structural activity relationship model to relate the calculated molecular descriptors of hydrazine derivatives to their experimental inhibition efficiencies obtained from literature. As a result, this model showed an excellent accuracy with an R‐squared of 0.924 and this uses to predict inhibition efficiencies of another molecules.

Protective nature of cerium-based oxides coating against Mg corrosion in Hanks’ balanced salt solution

The cerium-based coatings have attracted increasing attention for modifying Mg surface in biomedical applications due to their corrosion protectiveness and potential biological effects. However, their anti-corrosion mechanisms have not been fully understood. In this work, the corrosion resistance of anodic electrodeposited cerium-based oxides coating on Mg alloy was investigated in Hanks’ balanced salt solution. The obtained results demonstrate that the strengthened precipitation of protective calcium phosphate products on this coating results in its enhanced anti-corrosion nature. These findings enrich the understanding on anti-corrosion mechanisms of the cerium-based coating and point out its prospect on Mg alloys for bone implants.

Insight into the anti-corrosion mechanism of Pisum sativum L leaves extract as the degradable inhibitor for Q235 steel in sulfuric acid medium

BackgroundIn this work, we obtained Pisum sativum L leaf extract by soaking in sulfuric acid solution. Using sulfuric acid solution as solvent, the prepared Pisum sativum L leaf extract (PSLLE) has good solvent property and can be effectively dissolved in H2SO4 solution. Pisum sativum L leaf was selected as the research object, which is attributed to the large amount of Pisum sativum L cultivated in many countries and regions on the earth. Pisum sativum L leaf as a corrosion inhibitor, it can greatly realize the transformation of waste into treasure. MethodsThe Tafel curve data manifest that PSLLE is mixed-type inhibitor, which concurrently delaying the anodic and cathodic reactions of working electrode in sulfuric acid environment. Surface topography test results prove that PSLLE can form the stabilized isolation film after adsorption of Q235 steel, and the corrosion of Q235 steel is significantly descend. Theoretical results indicate that the active ingredient in PSLLE can emerge high standard anti-corrosion nature. Significant findingsWhen the concentration of PSLLE is 600 mg/L, its corrosion inhibition efficiency can reach 95.9% at 298 K. With the increase of temperature, PSLLE can still show high anti-corrosion performance. The adsorption isotherm model data showed that there was chemical and physical co-adhesion of PSLLE onto the Q235 steel surface. The PSLLE adhesion at Q235 steel surface is consistent with Langmuir monolayer model.

Corrosion inhibition of Pichia sp. biofilm against mild steel corrosion in 1 M H2SO4

Pichia sp. was isolated from rotten gooseberry (Phyllanthus emblica) and monitored for corrosion inhibition properties by means of biofilm-forming ability. The corrosion inhibition potential of Pichia sp. was evaluated against mild steel corrosion in 1 M H2SO4 via standard weight loss, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PP) techniques. Further, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray (EDX), X-ray photoelectron (XPS) spectroscopy, and atomic force microscopic (AFM) techniques were employed for confirming the biofilm accumulation on the mild steel (MS) surface. The weight loss investigation was carried out at varying temperatures (283 K−303 K), which showed the increasing trend of inhibition efficiency (IE%), and decreasing trend of corrosion rate, along with increasing Pichia sp. isolate’s concentrations. Pichia sp. isolate has shown maximum corrosion inhibition efficiency (>90%) at 283 K with an optimum concentration of 9 × 106 (CFU/mL). However, temperature studies insisted on the physical adsorption of corrosion inhibitor molecules over the metal surface. EIS data revealed enhanced values of charge transfer resistance (Rct), when increasing Pichia sp. isolate concentrations. Potentiodynamic polarization (Tafel curve) investigation revealed that Pichia sp. isolate exhibited mixed-type corrosion inhibition, while predominantly controlling the anodic reaction. The surface analysis data revealed the adherence and anticorrosive nature of Pichia sp. isolate on the MS surface, and a possible corrosion inhibition mechanism has also been discussed.

Incident Case Study of Baseline Pigging During In-Line Inspections for Corrosion Resistant Alloy Clad Pipelines

Abstract This paper describes an incident that occurred during the baseline inspections of pre-commissioning activities performed on a 20-in. metallurgically bonded corrosion resistant alloy (CRA) clad pipeline of an approximate length equal to 2.7 km. The inspection tool, deployed as part of the baseline inspections before the startup of the pipeline, was damaged in the CRA clad pipeline. This damage occurred despite extensive computer simulations, carried out before the inspection, which indicated that the tool, an ultrasonic (UT) pig, was able to traverse the length of the pipe without major issues. The application of the pressure surges was successful in dislodging the UT pig; however, as a direct consequence, the UT pig crashed into the pig receiver and sustained significant damage. The sealing pigs that were trailing behind the UT pig also collided with the rear of the UT pig, and it was at this junction that all further data transmission was ceased. A metal swarf was discovered upon inspection of the UT pig after retrieval, indicating that the inner wall of the pipeline also sustained damage. An analysis of the swarf indicated that it comprised solely of the CRA alloy that was metallurgically bonded to the inner wall of the carbon steel pipe. It was concluded that, due to the anticorrosive nature of the CRA material and high-quality control standards upheld during the manufacture of CRA pipes, the baseline in-line and routine inspections were unnecessary and can be detrimental if the inspection tool becomes impacted, thereby compromising the containment of the CRA layer.

Passiflora edulia Sims leaves Extract as renewable and degradable inhibitor for copper in sulfuric acid solution

In this research, we obtained Passiflora edulia Sims leaves Extract (PESLE) using a simple and green pure water extraction method. Experiment and theoretical calculations data show that PESLE can effectually restrain Cu corrosion in H2SO4 medium. Electrochemical results demonstrate that the PESLE is 800 mg/L, its anti-corrosion nature can reach about 96%. And with the augment of temperature, the anti-corrosion capacity of PESLE can still reach about 95% at a temperature of 318 K. SEM and AFM morphology test data show that PESLE is adsorbed onto the copper interface, the copper sample is effectively protected and the surface becomes relatively flat. The morphology test results directly prove that PESLE efficaciously restrain the corrosion of Cu in H2SO4 environment. XPS test results show that PESLE adsorption onto the Cu interface can detect Cu-N bond, which proves that chemical adsorption occurs. Quantum chemistry calculation data manifest that the three components of PESLE can reveal high anti-corrosion property. Molecular dynamics simulation data manifest the three components of PESLE can be adsorbed at the Cu (111) surface with paralleled way, and can have a large binding energy.

Shear capacity prediction of FRP-RC beams using single and ensenble ExPlainable Machine learning models

Corrosion in steel reinforcement is a central issue behind the severe deterioration of existing reinforced concrete (RC) structures. Nowadays, fiber-reinforced polymer (FRP) is increasingly being used as a viable alternative to conventional steel reinforcement due to its anti-corrosive nature. The accurate estimation of the shear capacity of FRP reinforced concrete (FRP-RC) elements is critical for a reliable and accurate design and performance assessment of such members. However, existing shear models are often developed based on a limited database and important factors, limiting their prediction effectiveness. Hence, this paper presents novel machine learning (ML) based models for predicting the shear capacity of FRP-RC beams. A total of eleven ML models starting from the simplest white-box models to advanced black-box models are developed based on a large database of FRP-RC beams. Such investigation helps in examining the necessity of complex ML models and identify the most accurate predictive model for the shear capacity of FRP-RC beam. Moreover, a unified framework known as SHapley Additive exPlanation (SHAP) is used to identify the most important factors that influence the shear capacity prediction of FRP-RC beams. Among all investigated ML models, the extreme gradient boosting (xgBoost) model showed the best performance with the lowest error (mean absolute error, root mean squared eror, and mean absolute percent error) and highest coefficient of determination (R2), Kling-Gupta efficiency, and index of agreement between the experimental and predicted shear capacities. Moreover, the accuracy of the proposed xgBoost model was compared with that of the available code and guideline equations and resulted in a superior prediction capability.

Insight on the corrosion inhibition performance of psidium guajava linn leaves extract

This work multi-angle explored the anti-corrosion nature and mechanism of psidium guajava linn leaves extract for copper in H2SO4 environment.In this study, we used a simple and eco-friendly extraction way to acquire psidium guajava linn leaves extract (PGLLE). Fourier Transform infrared spectroscopy (FTIR) was executed to determine the active functional groups in PGLLE. Quantum chemical calculations effectively forecast the anti-corrosion characteristic of the four active substances in PGLLE. The results of molecular dynamics simulation predicted the stabilized adsorption configurations of the four substances in PGLLE on the Cu (111). Surface topography analysis can intuitively demonstrate that PGLLE effectually inhibits Cu corrosion. The data of electrochemical experiments show that the anti-corrosion capacity of PGLLE increases with the increase of the concentration in a certain interval. As the temperature hoists at definite temperature range, PGLLE can still be efficaciously adsorbed at the Cu surface, showing high-quality corrosion inhibition capabilities. Psidium guajava linn leaves can exist widely in nature, so it has great economic value as the inhibitor. Besides, PGLLE basically does not pollute the ecosystem when used as inhibitors.

Luffa cylindrica roem leaves extract as the environment-friendly inhibitor for copper in sulfuric acid environment

This work mainly explored the anti-corrosion nature and mechanism of Luffa cylindrica roem leaves extract for Cu in H2SO4 environment. We used a green and environmentally-friendly pure water extraction method to obtain Luffa cylindrica roem leaves extract (LCRLE). We used FTIR to test the corresponding functional groups contained in LCRLE. And using quantum chemistry calculations and molecular dynamics simulations to deepgoing exploration of the corrosion inhibition activities of the three components. Surface morphology analysis shows that when LCRLE is added to the corrosion solution, LCRLE can effectively inhibit copper corrosion at 298 K for 20 h. The electrochemical tests data show that when LCRLE is contained, the copper electrode can be effectively protected. When the concentration of Luffa cylindrica roem leaves extract reaches 600 mg/L, its corrosion inhibition ability can reach 91.3%. The adsorption isotherm simulation shows that the adsorption of LCRLE at the Cu interface accords to the Langmuir mono-layer model. This work adopts the pure water method to obtain LCRLE, which has broad application prospects. Luffa cylindrica roem leaves are widely available, so the application cost of corrosion inhibitors will be greatly reduced.

Combining experiment and theory researches to insight into anti-corrosion nature of a novel thiazole derivatives

The propensity of acid corrosion for X65 steel substrate leads to application restrictions. In this research, we develop an efficient and new corrosion inhibitor, S-(benzo[d]thiazol-2-yl) (E)-2-(2-aminothiazol-4-yl)-2-(methoxyimino)ethanethioate (BTAE), as a first example of a sulfuric acid medium additive containing both benzothiazole and aminothiazole with multiple anchoring centers, which can inhibit the X65 corrosion in the sulfuric acid medium. The electrochemical experiment test shows that BTAE can effectually control the anodic reaction of X65 steel and belongs to the anodic type corrosion inhibitor. The corrosion inhibition efficiency of BTAE can still be maintained above 97% within a certain temperature range. The surface topography analysis and electrochemical test results are highly consistent. The adsorption of BTAE onto the interface of X65 steel conforms to the Langmuir model. Quantum chemistry and molecular dynamics simulation results have proved that BTAE is an excellent corrosion inhibitor.

Revealing the synergetic electrocatalyst behaviour of Kish graphite recovered from polyethylene plastics

Polyethylene plastic is a threat to the environment because of its enormous usage and limited recycling options. Herewith, the study reports the synthesis of Kish graphite from polyethylene waste. These wastes was mixed with molten iron and cooled into a rod-shaped mold. The molded iron ingots contain precipitated carbon material in 2D graphitic nature, which was obtained as Kish graphite after several acid treatments. The tafel studies show the anticorrosive nature of the sample with the corrosion potential of −1.6 V. Kish graphite and manganese oxide in the ratio 40:9 exhibited higher catalytic activity towards oxygen reduction reaction. Discharge studies of Mg-air battery with graphite (80%) air cathode recorded the highest capacity of 1226.51 mAh g−1, discharge life of 73.6 h and enhanced performance characteristics. Thus, waste polyethylene was effectively used as an supportive electrocatalyst in the Mg-air battery system.

Anticorrosive Behavior Enhancement of Stainless Steel 304 through Tantalum-Based Coatings: Role of Coating Morphology

Stainless steel (SS 304) has good mechanical strength and corrosion resistance properties, but it is not resistive to halides corrosion which limits the use of SS 304 in seawater applications. In this regard, the present work has been focused on the investigation of anticorrosive nature of Ta2O5 (tantalum pentoxide), Ta3N5 (tantalum nitride) and TaON (tantalum oxynitride) films deposited on AISI 304 stainless steel by RF reactive magnetron sputtering technique for anticorrosive applications. The predominant influencing factors especially film composition and surface morphology of the coatings were characterized by XRD, FE-SEM and AFM. The anticorrosive properties of the coatings were investigated through potentiodynamic polarization (Tafel) test and electrochemical impedance spectroscopy in 1M NaCl solution at room temperature. The morphological results showed that the films are uniform with low surface roughness, i.e., less than 10 nm. The contact angle and corrosion study of the films revealed that the tantalum oxynitride film, with nanoscale roughness, has greatly enhanced the corrosion protection of the stainless steel in 1M NaCl solution. The tantalum oxynitride film showed hydrophobic nature and the corrosion current density in the order of 10-11 A/cm2, which led to better anticorrosive behavior. The highest polarization resistance (Rp) was observed for tantalum oxynitride film, i.e., 3.14 MΩ. Overall, tantalum-based coatings have reduced the corrosion rate and enhanced the inhibition efficiency (more than 50%) in comparison with the bare SS 304 substrate.

Investigation of optical and anti-corrosive properties of reactively sputtered vanadium oxynitride thin films

Abstract In the present study, synthesis of Vanadium oxynitride thin films on various substrates are done using reactive magnetron sputtering technique. Physical and chemical properties were studied through XRD, FE-SEM and AFM methods. Optical and anti-corrosive properties were investigated by UV–Vis spectroscopy and potentiodynamic polarization (Tafel). Electrochemical impedance spectroscopy (EIS) methods were used to study the interaction of coating and 3.5 wt% NaCl solution. Reactively sputtered vanadium oxynitride films have good uniformity, low roughness i.e. below 50 nm and thickness of 250 nm in 30 min deposition. The study reveals that the vanadium oxynitride coating has an average transmittance of 42% in the wavelength range from 550 nm to 800 nm. The compound exhibited an energy band gap of 2.13 eV. The coatings show good anticorrosive nature by reducing the corrosion current by 6 times due to its passivating behavior.

Combining theoretical and experimental researches to insight the anti-corrosion nature of Citrus reticulata leaves extract

In recent years, natural plant extracts have received widespread attention as the novel and environment-friendly corrosion inhibitors. In this paper, we used the ultrapure water extract method to gain Citrus reticulata leaves extract (CRLE). The theoretical and experimental methods were used to explore the anti-corrosion nature of CRLE for Cu in sulfuric acid environment from multiple angles. Electrochemical experiments show that when the CRLE concentration was 500 mg/L, its anti-corrosion efficiency (η) can be as high as 97.3%. In addition, we explored the effect of soak time on the corrosion inhibition nature of CRLE. The experimental results shown that the copper electrode dip in the sulfuric acid solution containing 500 mg/L CRLE for 24 h, the η of CRLE can still reach more than 93%. Therefore, it can be shown that CRLE can form the stable barrier film on the Cu surface. In addition, the surface topography analysis results are conform to the electrochemical experimental results. The adsorption isotherm model studies manifest CRLE adsorb at the Cu interface conforms to the Langmuir monolayer adsorption. Quantum chemical calculations and molecular dynamics simulations have shown that CRLE can exhibit excellent anti-corrosion nature.

Combining experimental and theoretical researches to insight into the anti-corrosion property of Morinda citrifolia Linn leaves extracts

With the establishment of the concept of a community with a shared future for mankind, more and more eco-friendly corrosion inhibitors have attracted the attention of corrosion scientists. In this study, Morinda citrifolia Linn leaves extracts (MCLLE) were obtained using pure water extraction method. The extraction solvent, extraction method and the obtained product MCLLE will not cause damage to the ecological environment. The surface topography test vividly further proves that MCLLE can exhibit good anti-corrosion nature. Quantum chemistry calculation data show that (S)-2-amino-3(1H-imidazol-4-yl)propanoic acid (APA), 2-(6-Amino-purin-9-yl)-5-hydroxymethyl-tetrahydro-furan −3,4-diol (AHT), (S)-2-amino-4-(methylthio)butanoic acid (ABA), (S)-2-amino-3-(1H-indol-3-yl)propanoic acid (AIA), (S)-2-amino-5-guanidinopentanoic acid (AGA), (S)-2-amino-3-phenylpropanoic acid (APA) of MCLLE can exhibit brilliant corrosion inhibition property. In addition, molecular dynamics simulations show that APA, AHT, ABA, AIA, AGA, and APA have large binding energy on the copper surface, indicating that the obstacle film formed onto the copper surface is comparatively dense. Electrochemical experimental data indicate that the MCLLE anti-corrosion efficiency of 800 ppm can reach more than 95% for copper in 0.5 M H2SO4 environment. MCLLE can suppress the cathodic reaction and anodic reaction of the copper electrode. The adsorption of MCLLE onto the copper surface accords with Langmuir adsorption.

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.