Acidic Chloride Solutions Research Articles

Enhancement of corrosion protection of AISI 201 austenitic stainless steel in acidic chloride solutions by Ce-doped TiO2 coating

Ce-doped TiO2 coatings were applied by electrodeposition on a low-nickel austenitic stainless steel (AISI 201) bearing 8 wt% Mn to improve the electrochemical properties in acidic chloride solutions. Characterization of the Ce-doped TiO2 coatings was performed by a scanning electron microscope equipped with energy dispersive X-ray spectroscopy (EDS) to study the tiny features. The corrosion behavior of the bare and coated steel was evaluated in aqueous acidic chloride solutions mixing with different chloride concentrations, 1 mol·L−1 H2SO4 with 0–1.5% NaCl. Potentiodynamic polarization tests were conducted to evaluate the corrosion characteristics, corrosion potential Ecorr and corrosion current density icorr. Further study concerning the weight loss (WL) using immersion tests for the long-term was conducted to determine the bare and corresponding coated steel's equivalent corrosion rates. It was found that the electrodeposited Ce-doped TiO2 coatings with a layer thickness of ~1 μm enhance the corrosion resistance of the coated steel in the acidic chloride solutions compared to its counterpart, the bare steel. The polarization tests showed that the icorr of the Ce-doped TiO2 coated steel significantly declined to a half value of the bare steel. The Ecorr for all coated specimens shifted to a more positive value when compared with those of the bare steel. The WL measurements displayed that the bare AISI 201 steel experiences intensive corrosion degradation in the presence of a low concentration of chloride ions. However, the Ce-doped TiO2 coatings significantly resist the aggressive chloride ions and consequently increase the corrosion resistance of the steel.

Synthesis of a dual‐functionalized carbon‐based material as catalyst and supercapacitor for efficient hydrogen production and energy storage: Pd‐supported pomegranate peel

AbstractIn the current study, firstly, pomegranate peel (PP) was treated with phosphoric acid (H3PO4) and palladium chloride (PdCl2) solution. So, the PP‐supported Pd (PP‐H3PO4‐Pd) catalyst was synthesized for hydrogen production by the methanolysis reaction. In this context, different burning temperatures (300°C, 400°C, 500°C, and 600°C), and burning times (30, 45, 60, and 90 minutes) were examined to test the activity of the PP‐H3PO4‐Pd catalyst by the methanolysis reactions. As a result of studies, the most active catalyst was obtained by burning 45 minutes at 300°C (2 mL PdCl2solution 2% w/w). The maximum hydrogen production rate (HPR) obtained at 60°C by the methanolysis reaction was found as 37 240.4 mL min−1 g cat−1and the activation energy was calculated to be 26.83 kJ mol−1. Within the scope of this study, secondly, this PP‐H3PO4‐Pd catalyst was used as a supercapacitor active material for the first time to store electricity. Electrochemical characterization results were substantially similar to supercapacitor curves in the literature. At the current density of 1 A/g, the gravimetric capacitance of the prepared electrode was calculated as 84 F/g. Considering factors such as capacity, cost, and efficiency; the capacitance values of the produced ultracapacitor have a significant level.

Pretreatment of corn stover by acidic and basic choline chloride solutions for enzymatic hydrolysis

Pretreatment of corn stover by acidic and basic choline chloride solutions for enzymatic hydrolysis

Composition and structure of arsenic–antimony alloy electrodeposited from acidic chloride solution

AsSb alloy (0.70–95.81 wt.% As) was prepared by electrodeposition in As(III) and Sb(III) contained electrolytes. The influence of electrolyte composition, hydrochloric acid concentration, and temperature on the composition and structure of AsSb deposits was studied. The electroreduction mechanism of As(III) and Sb(III) in hydrochloric acid solution was revealed via thermodynamic analysis. The results show that the increase of H+ concentration promotes the reduction of As(III), while the increase of Cl− concentration significantly inhibits the reduction of Sb(III). As a result, the As content in deposits increases gradually with the increase of hydrochloric acid concentration. Simultaneously, the phase structure of AsSb deposits evolves from crystalline to amorphous. When the As content is 24.55–33.75 wt.%, AsSb mixed crystal is obtained. The electrolysis temperature has little effect on the deposits composition, but the structure of deposits evolves from crystalline to amorphous with decreasing the temperature.

Effect of pH on sacrificial anode aluminum alloy in acidic chloride solution

In this study, the effect of pH on sacrificial anode effect of aluminum alloy in acidic chloride solutions containing copper ion was investigated by using immersion corrosion tests and electrical polarization measurements. The corrosion tests were performed for A3003 alone and A3003 coupled with A7072 simulated clad material. A3003 was sacrificially protected by A7072 under the solution of over pH3 at 200 ppmCl‒. In contrast, in the case of a solution below pH2, the corrosion weight loss of A3003 coupled with A7072 did not decrease compared to that of A3003 alone. Additionally, A3003 coupled with A7072 actively dissolved similar to A3003 alone. These are because the corrosion potential of A3003 did not become less noble when coupled with A7072 due to nobler pitting potential of A7072.

Dynamics of formation of during inhibition of steel by sulfanilamide in solutions of hydrochloric acid with different pH

Experimentally proved by the method of polarization resistance formation of protective layers during inhibition steel corrosion by Sulfanilamide in aqueous solutions of hydrochloric acid with different pH. It is shown the difference due to the predominance of the protonated or unprotonated form of the molecule. It was found that at predominance of protonated forms of molecules (pH £2,4) formed dense protective films and predominance of unprotonated forms of molecules (pH ³2,4) are formed layers that do not inhibit diffusion processes. Sulfanilamide provides high and stable inhibition efficiency (<90%) in acid chloride solutions in case of formation protective layers consisting of protonated molecules what to consider when use it.

Influence of Laser Treatment on the Corrosion Resistance of Cr3C2-25(Ni20Cr) Cermet Coating

The influence of the laser treatment on the corrosion resistance of the Cr3C2-25(Ni20Cr) cermet coating on the Al7075 (EN, AW-7075) substrate (Cr3C2-25(Ni20Cr)/Al7075) was investigated. The coating was produced by the cold sprayed (CS) method. The tested coatings were irradiated with a laser spot speed of 600 mm/min, 800 mm/min, and 1000 mm/min. The mechanical properties of the Cr3C2-25(Ni20Cr)/Al7075 were characterized by microhardness (HV) measurements. The surface and microstructure of the specimens were observed by ascanning electron microscope (SEM) and other assistive techniques. The corrosion test of materials wascarried out by using the electrochemical method in the acidic chloride solution. Cermet coatings perfectly protect the Al7075 substrate against contact with an aggressive corrosion environment. The laser remelting process of the Cr3C2-25(Ni20Cr) layer caused the homogenization of the structure cermet coatings. The irradiation with the laser beam eliminates microcracks and pores on the Cr3C2-25(Ni20Cr) surface. However, the best effect of improving the anti-corrosion properties of cermet coating was obtained for the lowest laser spot speed (i.e., 600 mm/min). It was found that the corrosion rate of the Cr3C2-25(Ni20Cr) cermet coating was reduced by more than two times compared to the highest speed of the laser spot.

Evolution of the crater lake of Maly Semyachik volcano, Kamchatka (1965–2020)

Significant variations in temperature, water chemistry and volume of the lake in the crater of Maly Semyachik volcano, Kamchatka, in 1965–2020 can be divided in three main stages. The first stage, until about the mid-1980s, was characterized by intense volcanic-hydrothermal activity, high (above 40 °C) temperature, high salinity (up to 40 g/l) and an increase in the level (and volume) of the lake. During the second stage, which lasted 25–30 years, since the mid-1980s until the mid-2000s, the lake cooled down, until freezing in winter, the mineralization decreased (up to 1.6 g/l), and the volume of the lake remained almost constant. After the mid-2000s until present, there is a period of activation of the Maly Semyachik volcano, which is expressed in an increase in temperature, mineralization and a sharp increase in the volume of the crater lake. The water balance of the lake and the input and composition of the thermal acid chloride solution are estimated based on the analysis of changes in chemical and physical parameters over time, using a box model.

Performance-Based Selection of the Cathode Material for the Electrodeposition-Redox Replacement Process of Gold Recovery from Chloride Solutions

Recently, an emerging electrodeposition-redox replacement (EDRR) method was demonstrated to provide exceptionally efficient gold recovery from cyanide-free hydrometallurgical solutions. However, the effect of electrode material and its corrosion resistance in this process was overlooked, even though the EDRR process is carried out in extremely corrosive, acidic chloride solution that also contains significant amounts of strong oxidants, i.e., cupric ions. In the current study, nickel alloy C-2000, stainless steels 316L and 654SMO, and grade 2 titanium were for the first time critically evaluated as potential cathode materials for EDRR. The particular emphasis was placed on better understanding of the effect of cathode substrate on the overall efficiency of the gold recovery process. The use of a multiple attribute decision-making method of material selection allowed reaching of a well-founded compromise between the corrosion properties of the electrodes and process efficiency of gold extraction. The 654SMO steel demonstrated outstanding performance among the examined materials, as it enabled gold recovery of 28.1 pct after 3000 EDRR cycles, while its corrosion rate (CR) was only 0.02 mm/year.

Characterization structure of Fe3O4@PEG-4000 nanoparticles synthesized by co-precipitation method

Magnetic nanoparticles (Fe3O4) from natural iron sand with PEG-4000 have been successfully synthesized by the co-precipitation method. Natural iron sand was from Kulon Progo beach. Extraction of natural iron sand was separated with a magnet permanent as a precursor. The result of extraction was dissolved by acid chloride (HCl) solution. Precipitation process has been finished after added ammonium hydroxide (NH4OH) solution and added polyethylene glycol (PEG)-4000. This solution was dried until it formed a black precipitate. Magnetic nanoparticles were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and Fourier Transform Infra-Red (FTIR). The quantitative and qualitative analyzes on XRD were using the Profex 4.2.0 application and Joint Committee Powder on Diffraction Standards (JCPDS) No. 19-0629, respectively. Fe3O4 nanoparticles were successfully formed as indicated by the bonding of Fe-O. The results obtained in this study were the crystalline size of 11-13 nm with lattice parameters of 8.3758 Å for Fe3O4 and 8.3589 Å for Fe3O4 added with PEG. Fe nanoparticles were more dominant with wt% above 65%, which was confirmed by the EDX results. The addition of PEG mass resulted in the smaller crystallite size of the nanoparticles.

Corrosion Behavior of Inconel 625 Coating Produced by Laser Cladding

Anti-corrosion properties of Inconel 625 (In) laser cladding coatings onto the (S235JR) steel (S) were investigated. The coatings were produced with the use of wire (WIn/S) or powder (PIn/S). The mechanical properties of the Inconel 625 coatings were characterized by microhardness measurements. The PIn/S shows the highest hardness. The surface and microstructure of the specimens were observed by a scanning electron microscope (SEM). The surface analysis of the laser cladding coatings by energy-dispersive spectroscope (EDS) indicated that the structure of the WIn, and PIn coatings depend on its production technique. The microstructure of the WIn and PIn coatings have a dendritic columnar character. Corrosion test materials were carried out by using electrochemical methods. The corrosive environment was acidic chloride solution. It turned out that the PIn/S coating, which was produced by laser cladding method with the use of Inconel 625 powder, has the best anti-corrosion properties in an aggressive chloride environment.

(Invited) Electroless Rhodium Deposition for Metallization of Advanced Interconnects

Over the past decades, the semiconductor industry managed to continuously increase performance at an impressive, steady rate by scaling all parts of the integrated devices to nanometer-size dimensions, thereby enormously increasing the number of transistors on the chip as well as decreasing the dimensions of the metallization [1]. Presently, Cu constitutes the largest material fraction as conductor in damascene trenches which can be deposited by electrochemical deposition (ECD) or electroless deposition (ELD) [2 – 6]. For next-generation interconnects, the material properties (electromigration) of Cu render it unreliable for producing ever more performant chips. Additionally, the necessity of a diffusion barrier layer for Cu strongly increases line resistance and negatively impacts device performance upon further down-scaling. Recently, various alternative metals, such as ruthenium, rhodium, and molybdenum, have been studied and start to be implemented to tackle performance losses due to the small dimensions of the metal structures [7 – 9]. Consequently, both wet-chemical deposition as well as controlled etching of these metals has become of interest [10 – 12].In our contribution, we present results of the development of an electroless deposition bath for rhodium, using ruthenium (II) hexammine as reducing agent. An electrochemical characterization of the anodic and cathodic reactions involved was performed in hydrochloric acid and ammonium chloride solutions. The stability of Rh3+ and [Ru(NH3)6]2+ was monitored using UV-vis spectroscopy. It was found that under oxygen-free conditions the hexammine complex can be kept stable in the ammonium-containing solution.Initially, deposition experiments were performed on PVD-Pt blanket thin films, for which a non-uniform coverage was observed. Therefore, to enhance the nucleation of the ELD process, we first deposited a thin Rh layer by electrochemical deposition, after which Rh was deposited using our ELD bath. Transmission electron microscopy and elemental mapping was used to characterize the morphology and chemical composition, respectively. Upon thermal treatment (forming gas, 420 °C, 20 min) crystal grain growth was observed. Acknowledgements The authors would like to thank the partners of IMEC's Industrial Affiliation Program (IIAP) on Advanced Interconnects.

Synthesis and study of poly[(hydrazinylazo)]thiazoles as potent corrosion inhibitors for cast iron-carbon alloy in molar HCl: A collective computational and experiential methods

Herein, two poly[(hydrazinylazo)]thiazoles derivatives named, Poly[2-(2-(4-methylthiazol-2-yl)hydrazinyl)-4-methyl-5-((4-((4-(diazenyl)phenyl)sulfonyl)phenyl)diazenyl)thiazole] (TZP-1) and Poly[2-(2-(4-methylthiazol-2-yl)hydrazinyl)-4-methyl-5-((3-(diazenyl)phenyl)diazenyl)thiazole] (TZP-2) were regulated good yields by treatment of N-(4-((4-(2-(1-chloro-2-oxo propylidene)-hydrazinyl)phenyl)-sulfonyl)-phenyl)-2-oxopropane hydrazonoyl chloride or 1,3-phenylene bis-(2-oxopropane hydrazonoyl chloride) with hydrazine-1,2-bis-(carbothioamide). The configurations of the polymers are categorized by FT-IR and 1H NMR spectra. The effect of two synthesized poly[(hydrazinylazo)]thiazoles derivatives on the corrosion protection of cast iron-carbon alloy in acid chloride solution was examined using AC impedance spectroscopy, and potentiodynamic polarization (PPD) methods. The polarization resistance increased, and the corrosion current density declined with increasing polymer dose. TZP-2 revealed the maximum protection capacity PPDP/%= 97.8% at 50 mg/L. PPD studies exhibited that the performance of the titled polymer as mixed-type inhibitors and competitive chemically and physically adsorbed on alloy interface following the adsorption model of Langmuir. The morphological change of alloy surface was categorized by scanning electron microscopy (SEM). The adsorption energies of investigated poly[(hydrazinylazo)]thiazoles on iron(110) interfaces were computed by Monte Carlo (MC) simulations. The relation among specific quantum parameters and the protection capacity has been interpreted and recognizable correlations were detected.

Synthesis of a New Phosphonate-Based Sorbent and Characterization of Its Interactions with Lanthanum (III) and Terbium (III).

High-tech applications require increasing amounts of rare earth elements (REE). Their recovery from low-grade minerals and their recycling from secondary sources (as waste materials) are of critical importance. There is increasing attention paid to the development of new sorbents for REE recovery from dilute solutions. A new generation of composite sorbents based on brown algal biomass (alginate) and polyethylenimine (PEI) was recently developed (ALPEI hydrogel beads). The phosphorylation of the beads strongly improves the affinity of the sorbents for REEs (such as La and Tb): by 4.5 to 6.9 times compared with raw beads. The synthesis procedure (epicholorhydrin-activation, phosphorylation and de-esterification) is investigated by XPS and FTIR for characterizing the grafting route but also for interpreting the binding mechanism (contribution of N-bearing from PEI, O-bearing from alginate and P-bearing groups). Metal ions can be readily eluted using an acidic calcium chloride solution, which regenerates the sorbent: the FTIR spectra are hardly changed after five successive cycles of sorption and desorption. The materials are also characterized by elemental, textural and thermogravimetric analyses. The phosphorylation of ALPEI beads by this new method opens promising perspectives for the recovery of these strategic metals from mild acid solutions (i.e., pH ~ 4).

Rosemary oil as a Corrosion Inhibitor on High Carbon Steel in Citric Acid and Sodium Chloride: Weight Loss Study

The Inhibition effect of plant extract of rosemary oil (Rosmarinus officinalis) on corrosion of high carbon steel in 0.5M citric acid and 3.5wt% sodium chloride had been done by weight loss method. 0%, 0.50%, 1.00%, 1.50%, 2.00% and 2.50% concentration of rosemary oil was used on sodium chloride and citric acid solutions. Results from weight loss analysis shows that rosemary oil performed more strongly in sodium chloride solution compared to citric acid with excellent inhibition efficiency of 97.86% at 2.00% inhibitor concentration and 88.33% at 2.50% inhibitor concentration respectively. This shows that rosemary performed excellently in both corrosive environments.

Data on the corrosion Inhibition Property of Rosemary on High Carbon Steel in dilute sulphuric acid, citric acid and sodium chloride solution

The data of electrochemical analysis of Rosmarinus officinalis (RO) essential oil effect on high carbon steel (HCS) in three different corrosive environment of sodium chloride, sulphuric acid and citric acid solution was achieved via weight loss method. Results revealed that Rosmarinus officinalis (RO) organic compound performed excellent well on high carbon steel samples with the optimum inhibition value occurring in NaCl solution with 97.87% after 504 h. The corrosion rate values were significantly high at 0 ml RO organic compound for all the three (3) corrosive environments as the time of immersion moves down to 504 h. It was clearly observed that time of immersion and concentrations of RO are the main determinant factor for the excellent adsorption performance of RO organic compound within the range of 504 h. Also, Rosmarinus officinalis (RO) organic compound retarded the severe corrosion rate of high carbon steel samples in other corrosive solutions with average range inhibition values between 40 and 78% after 504 h.

Adsorption of Gold from Acid Thiourea and Chloride Solutions by Ion Exchange Resins.(Dept.M)

Adsorption of Gold from Acid Thiourea and Chloride Solutions by Ion Exchange Resins.(Dept.M)

Selective Extraction of Sc(III) over Y(III) and Fe(III) with a Deep Eutectic Solvent Composed of N-Lauroylsarcosine and Tri-n-octylphosphine Oxide

ABSTRACT Demand for scandium (Sc) has been increasing in recent years. However, there are almost no ores containing Sc, and the supply is insufficient because the separation and recovery of Sc as a byproduct from oxide minerals such as ilmenite ore, bauxite, and laterite are difficult. In this study, extraction and separation of Sc3+ from acidic chloride or acidic nitrate solutions containing transition metals such as Fe3+, Co2+, Ni2+, Zn2+, and Pd2+ were studied using N-lauroylsarcosine (NLS) and tri-n-octylphosphine oxide (TOPO), which together create a “deep eutectic solvent” (DES). Owing to the respective selectivity of NLS and TOPO by different extractive interactions between metal ions and the two extractants in toluene, Sc3+ was effectively and selectively separated even from Fe3+ in the aqueous ammonium nitrate solution, the mutual separation of which is difficult with NLS alone. The mutual separation of Sc3+ and Fe3+ in acidic chloride solution is in general very difficult, while the mutual separation of these metals from acidic nitrate solution is successful. This is due to either anions forming complexes with Sc3+ in the aqueous phase (chloride) or not (nitrate). The potential use of the combination of the NLS with TOPO for selective recovery of Sc3+ from Fe3+ in a refining process is demonstrated.

Surface and interface analysis of iron sulfides in aqueous media using X-ray photoelectron spectroscopy of fast-frozen dispersions

Iron sulfides are important minerals and materials, whose surface properties are largely determined by the interface with aqueous phases. Here, natural pyrrhotite (Fe9S10) and pyrite (FeS2) were ground, reacted in water and acidic non-oxidative and oxidative ferric chloride and sulfate solutions, then centrifuged, fast-frozen and examined with X-ray photoelectron spectroscopy at –160 °C (cryo-XPS) in comparison with the samples thawed in vacuum, dried in vacuum or air and measured at room temperature (RT). The interfacial layers were composed mainly of ferric (hydr)oxides and aqueous iron salts as the reaction products rather than reactants; RT-XPS found the products modified due to dehydration, further reactions and redistribution over the surface. The cryo-XPS revealed plentiful surface Fe-S centers with various spin and oxidation states at pyrrhotite and pyrite, particularly in water, missed in conventional XPS. The surfaces of pyrrhotite and, much less, pyrite are enriched with polysulfide anions -S-Sn-S-, which partially volatilize at RT both under non-oxidative and oxidative conditions; the number n can be larger than 6 at pyrrhotite. It was concluded, nevertheless, that elemental sulfur insignificantly contributes to the spectra under the conditions employed. Pros and cons of the technique in the case study of iron sulfides are discussed.

Corrosion Mechanisms of High-Mn Twinning-Induced Plasticity (TWIP) Steels: A Critical Review

Twinning-induced plasticity (TWIP) steels have higher strength and ductility than conventional steels. Deformation mechanisms producing twins that prevent gliding and stacking of dislocations cause a higher ductility than that of steel grades with the same strength. TWIP steels are considered to be within the new generation of advanced high-strength steels (AHSS). However, some aspects, such as the corrosion resistance and performance in service of TWIP steel materials, need more research. Application of TWIP steels in the automotive industry requires a proper investigation of corrosion behavior and corrosion mechanisms, which would indicate the optimum degree of protection and the possible decrease in costs. In general, Fe−Mn-based TWIP steel alloys can passivate in oxidizing acid, neutral, and basic solutions, however they cannot passivate in reducing acid or active chloride solutions. TWIP steels have become as a potential material of interest for automotive applications due to their effectiveness, impact resistance, and negligible harm to the environment. The mechanical and corrosion performance of TWIP steels is subjected to the manufacturing and processing steps, like forging and casting, elemental composition, and thermo-mechanical treatment. Corrosion of TWIP steels caused by both intrinsic and extrinsic factors has posed a serious problem for their use. Passivity breakdown caused by pitting, and galvanic corrosion due to phase segregation are widely described and their critical mechanisms examined. Numerous studies have been performed to study corrosion behavior and passivation of TWIP steel. Despite the large number of articles on corrosion, few comprehensive reports have been published on this topic. The current trend for development of corrosion resistance TWIP steel is thoroughly studied and represented, showing the key mechanisms and factors influencing corrosion processes, and its consequences on TWIP steel. In addition, suggestions for future works and gaps in the literature are considered.