Metal Corrosion Research Articles

Investigation of kinetics and mechanisms of metallic beryllium corrosion for the management of radioactive wastes

Activated beryllium wastes are produced by the nuclear industry and have to be managed as radioactive waste during decommissioning and dismantling of nuclear facilities. One potential approach to the management of these wastes is their encapsulation and stabilization in cementitious matrices. The main issue with this conditioning is aqueous corrosion, leading to the hydrogen production and potential crack formation leading to a loss of confinement. To evaluate the suitability of different cement formulations, such as Ordinary Portland Cement (OPC) or magnesium phosphate cement for encapsulation of metallic beryllium, the corrosion behaviour of beryllium metal was investigated in solutions with different pHs. In alkaline solutions representative of OPC pore fluids (i.e. NaOH solutions with pH between 12.5 and 14), corrosion rates increase drastically with increasing pH. Investigations of the surface of the corroded beryllium samples by scanning electron microscopy indicate that pitting corrosion is the main corrosion mechanism under these conditions.Graphical abstract

Swing Origami-Structure-Based Triboelectric Nanogenerator for Harvesting Blue Energy toward Marine Environmental Applications.

The appearance of triboelectric nanogenerators (TENG) provides a promising energy technology for harvesting abundant water wave energy. Here, the design and fabrication of a swinging origami-structured TENG (SO-TENG) tailored specifically for water wave energy harvesting are presented. The design incorporates an oscillating structure weighted at the bottom, inducing reciprocating motion propelled by the inertia of passing water waves. This reciprocating motion efficiently converts mechanical into electrical energy through the origami structure. By employing origami as the monomer structure, the surface contact area between friction layers is enhanced, thereby optimizing output performance. the swinging structure, combined with the placement of heavy objects, enhances the folding and contact of the origami, allowing it to operate effectively in low-frequency water wave environments. This configuration exhibits robust power generation capabilities, making it suitable for powering small electronic devices in water wave environments. Furthermore, when applied to metal corrosion protection, the SO-TENG demonstrates notable efficacy. Compared to exposed Q235 carbon steel, Q235 carbon steel protected by SO-TENG exhibits a significant reduction in open-circuit potential drop, approximately 155 mV, indicative of superior anti-corrosion properties. It lays a solid foundation for water wave energy collection and self-powered metal corrosion protection in marine environments.

Deciphering the Performance Enhancement, Cell Failure Mechanism, and Amelioration Strategy of Sodium Storage in Metal Chalcogenides-Based Andes.

Transition metal chalcogenides (TMCs) emerge as promising anode materials for sodium-ion batteries (SIBs), heralding a new era of energy storage solutions. Despite their potential, the mechanisms underlying their performance enhancement and susceptibility to failure in ether-based electrolytes remain elusive. This study delves into these aspects, employing CoS2 electrodes as a case in point to elucidate the phenomena. The investigation reveals that CoS2 undergoes a unique irreversible and progressive solid-liquid-solid phase transition from its native state to sodium polysulfides (NaPSs), and ultimately to a Cu1.8S/Co composite, accompanied by a gradual morphological transformation from microspheres to a stable 3D porous architecture. This reconstructed 3D porous structure is pivotal for its exceptional Na+ diffusion kinetics and resilience to cycling-induced stress, being the main reason for ultrastable cycling and ultrahigh rate capability. Nonetheless, the CoS2 electrode suffers from an inevitable cycle life termination due to the microshort-circuit induced by Na metal corrosion and separator degradation. Through a comparative analysis of various TMCs, a predictive framework linking electrode longevity is established to electrode potential and Gibbs free energy. Finally, the cell failure issue is significantly mitigated at a material level (graphene encapsulation) and cell level (polypropylene membrane incorporation) by alleviating the NaPSs shuttling and microshort-circuit.

Metalized Plastic Current Collectors Incorporated with Halloysite Nanotubes toward Highly Safe Lithium‐Ion Batteries

AbstractMetalized plastic current collectors (MPCCs) have shown potential in improving the energy density and safety of lithium‐ion batteries (LIBs). However, the poor mechanical strength, weak interfacial adhesion force, and surface metal corrosion have impeded the practical application of MPCCs. Here, an innovative engineering of MPCCs is proposed by incorporating halloysite nanotubes (HNTs) as fillers into polyimide (PI) polymer layer, which is further coated with two thin copper (Cu) layers. Because of the strong bonding between HNTs surface and the PI precursor, HNTs improve the mechanical strength of PI‐HNTs composite film, reinforce the interfacial adhesion force between the PI‐HNTs film and the coated Cu layer, and suppress the Cu corrosion by electrolyte. The prepared MPCCs exhibit a low mass density and only account about one‐fifth of the density of commercial Cu CCs. Furthermore, the PI‐HNTs‐Cu composite demonstrates significantly enhanced interfacial adhesion force doubled to 4 N cm−1 along with prolonged stability under electrolyte immersion and electrochemical reaction conditions, and delivers a high fracture strength of 125 MPa. LIBs assembled with MPCCs deliver a twice higher discharge capacity compared to battery with Cu CCs and reach a long‐term cycle capacity retention as high as 92.9% at 0.5 C after 500 cycles.

High-Loading Smart Carrier Containing 2-Mercaptobenzimidazole-Zn2+-Polydopamine with pH-Responsive Function to Fabricate High-Performance Waterborne Epoxy Anticorrosion Coatings.

Corrosion inhibitor additives are considered to be one of the effective methods to slow down the corrosion of metals, but the corrosion inhibitors will decompose and lose their effect in a long-term corrosive environment. In this work, a smart corrosion inhibitor carrier 2-mercaptobenzimidazole-Zn2+-polydopamine@graphite (MZPG) with excellent pH response was designed and synthesized using a one-pot method. This corrosion inhibitor carrier not only has a very high 2-mercaptobenzimidazole (MBI) loading capacity (38.0%) but also maintains a very low MBI activity to inhibit the decomposition of MZPG in the environment as much as possible. The MZPG/epoxy (MZPG/EP) coatings prepared by the spraying method showed excellent mechanical properties. Electrochemical and salt spray tests showed that the MZPG/EP coatings (1.20 × 1010 Ω·cm2) have excellent corrosion resistance with Rp values up to 3 orders of magnitude higher than that of the EP coating (1.25 × 107 Ω·cm2). Notably, the MZPG/EP coatings maintained good corrosion resistance under acidic conditions due to the pH-responsive release of corrosion inhibitors. This is of great significance for the future development of coatings for highly corrosive environments.

Electropolymerized conducting polyaniline coating on nickel-aluminum bronze alloy for improved corrosion resistance in marine environment

Corrosion of metals in marine environments is a vital problem with significant negative economic impacts and coating is an effective measure of protection. In this work, polyaniline (PANI) conducting polymer was deposited as a protective layer on a nickel-aluminiumbronze (NAB) alloy using the galvanostatic electropolymerization method at different current densities. The deposited coating was characterized by various techniques such as FTIR and SEM. To evaluate its effectiveness in corrosion protection, the anticorrosion properties of different PANI coatings were evaluated in a 3.5 wt% NaCl solution by both potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The electrochemical results revealed that PANI coatings acted as a barrier towards the corrosive species and provided significant corrosion resistance to NAB degradation, with an inhibition efficiency of about 93% and a mixed-type inhibition behavior with cathodic predominance. Furthermore, corrosion protection was found to be dependent on the coated film properties and the optimum corrosion inhibition was achieved under the test conditions for films deposited at a current density of 5 mA cm-². Moreover, Raman spectroscopy confirmed the presence of the partially oxidized conductive polyaniline, the emeraldine form and its polaron structure, on the alloy surface. In addition, atomic force microscopy (AFM) was used to monitor the changes in the microstructure of the coating after exposure to the saline environment and demonstrated the formation of a robust coating with a significantly lower (5 times) surface roughness for the coated alloy than the uncoated surface after immersion. Overall results strongly support the potential of PANI for corrosion protection of the NAB alloy.

Turmeric (Curcuma longa) Extract Characterization for Corrosion Inhibitor using Microwave-Assisted Extraction

<p>Metallic corrosion, the deterioration process induced by the interaction between metals and corrosive environments, poses a significant challenge to material integrity and longevity. Corrosion inhibitors have been identified as an effective approach among various mitigation strategies. Natural extracts, such as those derived from turmeric/<em>Curcuma longa</em>, have garnered attention for their potential as eco-friendly corrosion inhibitors. This study endeavors to extract, characterize, and evaluate turmeric extract's efficacy as a corrosion inhibitor within a 30% acetic acid solution. Employing microwave-assisted extraction with a 96% ethanol solvent facilitated the isolation of the extract, which was subsequently subjected to qualitative analysis through phytochemical screenings and Gas Chromatography-Mass Spectrometry (GC-MS). These analyses confirmed the presence of antioxidative phytochemicals, including alkaloids, terpenoids, turmeronoids, curcumin, sesquiterpenoids, and phenols. The corrosion inhibitory properties of turmeric extract were assessed via immersion and flow loop experiments, revealing a notable reduction in corrosion rates—from 0.1540 mm/year to 0.0801 mm/year in immersion tests and from 5.3747 mm/year to 2.9369 mm/year in flow loop tests. Such outcomes underscore turmeric extract's potential as a viable corrosion inhibitor, attributed primarily to the chemical interactions facilitated by curcumin's phenolic and carbonyl groups with the metal surface, thereby enhancing protective efficacy. The inhibitor efficiency was quantified at 47.9743% and 45.3565% for immersion and flow loop tests, highlighting the extract's substantial inhibitory performance.</p>

Double-layer with electroactive and superhydrophobicity based on polymer nanotubes to improve robustness and anti-corrosion performances

The phenomena of corrosion in metals have resulted in significant damage to the day-to-day lives of humans, the routine maintenance of engineering metal materials, and catastrophic corrosion damage has also triggered huge economic losses. Herein, we propose a double-layer PDVB/FSiO2-PDVB@PPy/EP sprayable coating with excellent robust superhydrophobicity and electroactive based on mass-producible polydivinylbenzene nanotubes (PDVB NTs) to apply in anti-corrosion of Q235 steel plate. On one hand, the electroactive base layer of PDVB@PPy/EP can constitute a physical barrier against corrosive media; On the other hand, cross-linked PDVB NTs containing FSiO2 NPs (PDVB/FSiO2 NTs) can form a superhydrophobic surface structure to avoid substrate corrosion from corrosive liquid. The water contact angle (WCA) of the composite coating is 163.9° and the sliding angle (SA) is 3.6°, indicating that the coating possesses excellent superhydrophobic properties. Remarkably, Cross-cut scratch, tape peel, and Taber abrasion tests confirm that the composite coating exhibits excellent robust performance. The pitting pit depth after 30 days of salt spray test is 4 μm, and following 60 days of immersion in a solution containing 3.5 wt% NaCl, the protection efficiency (P.E.%) reaches 94.79 %. These results suggest that the double-layer electroactive superhydrophobic coating exhibits excellent corrosion resistance.

Towards improved online dissolution evaluation of Pt-alloy PEMFC electrocatalysts via electrochemical flow cell - ICP-MS setup upgrades

Electrochemical flow cell coupled with an inductively coupled plasma mass spectrometer (EFC-ICP-MS) is a powerful electroanalytical technique to monitor in-situ dissolution of metallic electrocatalysts and to understand mechanism of degradation under operating conditions. Its utilisation has witnessed a notable increase in the electrocatalyst field in the last decade where it has been extensively used to study the stability of platinum group metals (PGMs) under oxygen reduction and oxygen evolution reaction conditions. Online ICP-MS has allowed the scientific and industrial community to optimise the activity and stability of PGMs thanks to a better understanding of the complex metal corrosion processes. Among the different setups, the electrochemical flow cell design is the most common as it is based on a commercially available design. Nonetheless, besides different materials and different electrochemical protocols, the impact of the geometry and various parameters of the setup on the recorded dissolution signal has not been studied until now. Such parameters can influence the results obtained with an EFC-ICP-MS and thus the interpretation of the dissolution mechanism and/or stability assessment. Hereby, we demonstrate that the length of the tubing between the outlet of the cell and the inlet of the ICP-MS impacts the resolution of the PtCo catalyst dissolution peaks. This, in turn, facilitates studies where the detection of extremely low concentrations is necessary, such as under a very narrow potential window. Similarly, a reduced internal volume of the cell restricts Pt redeposition, contributing to a more precise evaluation of stability. These claims were supported by dynamic continuum mechanics modelling of the ion concentration in a model EFC. Finally, we provide guidelines and advice to properly measure dissolution with an electrochemical cell coupled with ICP-MS.

Potentiostatic oscillations of current and surface structure in a 3D cellular automaton model of metal passivation

Some recently obtained data from simulations in our 3D cellular automaton model on metal passivation are presented and discussed. The model is a non-equilibrium heterogeneous Ising-like model with moving boundary due to metal depletion by corrosion. The mobile particles representing metal oxide are produced in corrosion events. They bind to the metal surface and to each other with short range interaction. They diffuse by random walk with asymmetric exclusion and disappear in the bulk solution.The results of this paper are obtained in potentiostatic conditions. In our model, this amounts to a fixed bare metal corrosion rate. The results include current transients and surface snapshots at a number of moments of time. We define several other dynamic variables. Their transients allow us to construct phase portraits, to identify the bare metal surface area and the oxide layer thickness as the essential variables for the oscillations. The first of those is equivalent to current density by model construction. The second plays a peculiar role in periodic current spiking, as discussed in the text.

Pengaruh ketahanan korosi logam alumunium terhadap variasi pada larutan asam klorida 0,1 M dan 0,5 M

Background: Corrosion is a decrease in the quality of a material or metal to electrolyte reactions in the environment that affect the life of the material. Corrosion processes occur in acidic environments, sea water, rainwater, and soil are the result of chemical reactions that are also caused by electrochemical processes. The purpose of this study was to determine the corrosion resistance of aluminum metal to variations in 0.1 M and 0.5 M Hydrochloric Acid solution. This research uses an aluminum plate that will be immersed for 5 days with 0.1 M HCl and 0.5 M HCl solution. Methods: The method of data collection is by scanning Scanning Electron Microscopy (SEM) on each aluminum plate specimen that has been given corrosion treatment by heating at a temperature of 60 C HCl solution is one of the factors causing corrosion of metals. Finding: If in the free environment, air, temperature, and acidic substances are most commonly found as a factor causing corrosion. The increased corrosion rate is due to the higher concentration of the cause of corrosion. Conclusion: In this discussion, HCl as a concentration is used, and aluminum as a metal is tested.

Ni–Zn bimetal-organic framework nanoprobes reinforced polymeric coating to achieve dual-responsive warning of coating damage and interfacial corrosion

Coating microdefects and localized corrosion in coating/metal system are inevitable, accelerating the degradation of metal infrastructure. Early evaluating coating microdefects and detecting corrosion sites are urgent yet remain challenge to achieve. Herein, we propose a robust, universal and efficient fluorescence-based strategy for hierarchical warning of coating damage and metal corrosion by introducing the concepts of damage-induced fluorescence enhancement effect (DIE) and ionic-recognition induced quenching effect (RIQ). The coatings with dual-responsiveness for coating defect and steel corrosion are constructed by incorporating synthesized nanoprobes composed of metal organic frameworks (Ni–Zn-MOFs) loaded with Rhodamine B (RhB@MOFs). The initial damage to the coating causes an immediate intensification of fluorescence, while the specific ionic-recognition characteristic of RhB with Fe3+ results in an evident fluorescence quenching, enabling the detection of coating damage and corrosion. Importantly, this nanoprobes are insensitive to the coating matrix and exhibit stable corrosion warning capability across various coating systems. Meanwhile, electrochemical investigations indicate that the impedance values of RM/EP maintain above 108 ​Ω ​cm2 even after 60 days of immersion. Therefore, the incorporation of fluorescent nanoprobes greatly inhibits the intrusion of electrolytes into polymer and improves the corrosion protection performance of the coating. This powerful strategy towards dual-level damage warning provides insights for the development of long-term smart protective materials.

Corrosion of Old Overhead Lines: Insights into Aluminum-Steel Galvanic Couple Using Electrochemical Techniques

In order to explain the corrosion inside 20th century power lines, the galvanic corrosion of steel and aluminum from 1949 was examined. In this investigation, 0.1 M Na2SO4 + 1 mM NaCl was used as moderately corrosive medium. Various electrochemical methods were applied to determine the corrosion potential and the different reactions involved in the corrosion process. The thickness of the oxide layer that regulates the corrosion of aluminum was obtained from impedance measurements and it was shown that the diffusion of oxygen through a porous oxide layer is the governing stage for the reaction occurring at the steel electrode. Finally, the corrosion of steel regulates the corrosion of both metals when they are in electrical contact.

Study of The Inhibition Corrosion of Aluminum Metal Using Peppermint Oil in An Acidic Medium

This study included the study of the efficiency of peppermint oil inhibition of aluminum corrosion in acidic medium HCl at concentrations (0.5, 1, 1.5, 2 M) on the corrosion rate in the presence and absence of the inhibitor peppermint oil at different concentrations (1000, 2000, 3000, 4000 ppm).In order to study the effect of changing the temperature (303, 313, 323, 333 K) on the corrosion rate in the absence and presence of the inhibitor, different concentrations of the inhibitor were chosen in addition to the acid concentration (1M). The experiments were carried out using the weight loss method to calculate the erosion rate. The expected heat of adsorption enthalpy was (-29.913 KJ/mol), with a negative sign indicates that the process is exothermic. The value of the free energy of adsorption ranged from (11.086-15.067 KJ/mol. (The results showed that Freundlich adsorption isotherm equation is the best fit to examine the adsorption process, also a scanning electron microscope. Showed the surface of aluminum before and after corrosion according to the results of the study, it was found that the used inhibitor reduces corrosion in acidic media. Its anti-corrosion efficacy also improves with increasing inhibitor concentration and with decreasing temperature.

Diatomite@MoS2 Nanocomposite Layers as Composite Coating Targeting for Mg Alloys Endowed with Properties of Anticorrosion and Antiwear.

Molybdenum disulfide (MoS2) demonstrates promising applications in enhancing the corrosion and wear resistance of metals, but the susceptibility of this nanomaterial to agglomeration hinders its overall performance. In this study, the externally assisted corrosion inhibitor sodium molybdate (SM) was successfully constructed in diatomaceous earth (DE) and molybdenum disulfide (MoS2). This not only served as a molybdenum source for MoS2 but also enabled the preparation of DE@MoS2-SM microcapsules, achieving a corrosion inhibitor loading of up to 23.23%. The corrosion testing reveals that the composite coating, when compared to the pure epoxy coating, exhibits an impedance modulus 2 orders of magnitude higher (1.80 × 109 Ω·cm2), offering prolonged protection for magnesium alloys over a 40 day period. Furthermore, a filler content of 3% sustains a coefficient of friction (COF) at 0.55 for an extended duration, indicating commendable stability and wear resistance. The protective performance is ascribed to the synergistic enhancement of corrosion and wear resistance in the coatings, facilitated by the pore structure of DE, the high hardness of MoS2, and the obstructive influence of Na2MoO4. This approach offers a straightforward and efficient means of designing microcapsules for use in corrosive environments, whose application can be extended in industrial fields. In particular, we promote the application of nautical instruments, underwater weapons, and seawater batteries in the shipbuilding industry and marine engineering.

Снижение биокоррозии деталей оборудования, эксплуатируемого в подземных выработках за счет применения детонационного Ti-Cu напыления

Introduction. The wide distribution of microorganisms in the natural and technogenic environment, in the conditions of underground mine workings, is explained by their phenomenal adaptation capabilities. The high activity of microorganisms at significant depths under extreme conditions is due to the peculiarities of their metabolism. The maximum number of these factors is typical for underground mining. The lithosphere, in which underground structures are built to ensure the development of deposits, in addition to its well-known characteristics, is also a habitat for microorganisms. The waste products of these microorganisms significantly influence the rate of corrosion of metals. Often the scale and speed of bio damage are so significant. Therefore, the study of microbial bio damage processes and their prevention under these conditions is an extremely urgent task. Materials and methods. The corrosion rate in an aggressive biological environment of three types of samples was studied. The first type of samples were ordinary plates made of St 3. The second type of samples was the same St 3 but with antimicrobial enamel XC-5286 applied to the surface. And the third type of samples were samples made of St 3 with a detonation coating applied to their surface from a mixture of Ti (PTN-8VT10) and Cu (PMS-1) powders. These samples were exposed to a biologically active corrosive environment for one month. Then the level of damage and corrosion development on the surface of the samples was measured. Results. The results of the study showed that the use of the method of detonation thermal spraying makes it possible to form a protective Ti-Cu composite coating with anti-corrosion properties on the surface of low-carbon steel. The rate of biological corrosion of steel samples with Ti-Cu coating is 40% less than on control samples without such a coating. The anti-corrosion efficiency of the XC-5286 coating was 80%. Discussion. The antimicrobial effectiveness of Cu ions primarily depends on their concentration adjacent to the coating surface, which in turn is determined by the rate of release of biocide ions. When immersed in an aqueous solution, copper (I) oxide (Cu2O), which is part of both the XC-5286 coating and the Ti-Cu composite coating formed by thermal spraying, is unstable and, under the influence of chlorine, hydrogen and oxygen ions, quickly oxidizes to more stable divalent copper ions Cu2+. To maintain the required level of antimicrobial effect, the average rate of release of copper ions from contact-type coatings (which includes XC-5286) must be at least 50 μg/cm2 day. The rate of release of Cu ions from a composite Cu-Ti coating formed by plasma spraying is about 20.5 μg/cm2 day, which is almost 2 times less than the required level. This explains the lower antimicrobial efficiency (AE) of Ti-Cu composite coatings compared to XC-5286 enamel, which has an AE value of 80.5%. As shown by full-scale tests, even at low values of the release rate of Cu ions, the coating under study provides effective inhibition of the development of bio corrosion. Conclusions. The work established that the use of the method of detonation thermal spraying made it possible to form a protective Ti-Cu composite coating with anti-corrosion properties on the surface of low-carbon steel. Resume. The work established that the use of the method of detonation thermal spraying made it possible to form a protective Ti-Cu composite coating with anti-corrosion properties on the surface of low-carbon steel. Such Ti-Cu-based coatings can be used not only to protect mechanisms, structural elements and structures operating in mining conditions, but also for their operation in humid climates subject to periodic wetness.

Microwave assisted self-repairable vitrimeric coating for anti-corrosive applications

Vitrimeric coatings are revolutionary and most widely emerging materials for metal corrosion inhibition. As harsh environmental conditions damages polymer-derived protective films and results into micro cracks and corroded metal surfaces. In this work, an active microwave responsive vitrimeric epoxy coating embedded with weathering resistant properties is introduced along with systematic comparative study for the effect of ortho and para position of amine in hardening agent. The developed microwave radiation responsive coating system felicitates self-healing due to disulfide exchange mechanism and corrosion inhibition properties in marine environments. Compared to conventional coatings, prepared graphene oxide (GO) incorporated vitrimeric network showed more promising protection against corrosion in offshore applications with 95.4 % protection efficiency and hydrophobicity with 96-degree contact angle. This study covers the self-healing properties, thermal mechanical study, hydrophobicity measurement, and thorough corrosion examination of synthesized material coated on 304 grade SS substrate. The coating reports excellent self-healing efficiency, reliable mechanical strength (storage modulus-129GPa and loss modulus-83GPa), fast stress relaxation and low activation energy (63KJ/mol) for dynamic disulfide exchange reaction, furthermore low corrosion rate of 1.20 × 10−3mm/y was observed for the coating. Thus, demonstrates its importance for self-healable anti-corrosive application for the marine environment.

Deciphering the corrosion puzzle: Nano-iron-biochar composite – Not a quick fix for metal immobilization in peat soils

The use of zero-valent iron nanoparticles in the remediation of metal-contaminated soils has received considerable attention. Upon introduction into the soil, zero-valent iron particles corrode into iron oxides, known for their high adsorption capacity for potentially toxic metals. While limited research has directly compared zero-valent iron micro- and nanoparticles, it is important to investigate whether particle size contributes to effective soil remediation. This study focuses on elucidating the comparative kinetics of iron corrosion using iron powder and a nano-iron-biochar composite. In a model experiment, these materials were exposed to a cellulose/biochar mixture and peat for five months. Mössbauer spectroscopy, X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy, and transmission electron microscopy with electron diffraction were used to analyze the corrosion products. The results show a slow corrosion rate in the nano-iron-biochar composite in cellulose due to the protective effect of biochar on the embedded iron nanoparticles. In addition, iron corrosion in peat was inhibited, likely due to the presence of humic substances. Transmission electron microscopy after five months of corrosion revealed round metal particles encased in a graphite capsule with visible channels. Large dissolved organic matter molecules in the peat likely block these channels, inhibiting metallic iron corrosion. Consequently, the nano-iron-biochar composite emerges as a slow-reacting option for immobilizing soil metals in peat. This study highlights the need for further research involving long-term field experiments.

Research on the Mechanism and Preventive Measures of Heat Transfer and Coking in Boilers

Boilers are one of the most important power supply sources in the chemical industry. The irreplaceable nature of its products requires boilers to maintain stable long-cycle operation during the production process. However, boiler failures occur from time to time and necessary measures need to be taken to reduce the chances of failure. Among these failures, metal corrosion and tube failures are particularly prominent. Due to the fact that the thermal calculation results do not match the actual; the coefficients in the design are not reasonably selected, and the hearth and boiler shape are not properly selected; the structural design of the superheater system and the arrangement of the heated surface are not reasonable; and the wall temperature calculation method is not perfect, which leads to the improper selection of materials and so on. These will make the fire-side heat exchange system produce wall temperature super-high, tube bundle burst and other failure phenomena. These phenomena cause a certain degree of hidden danger to the safe production of the boiler.

BTA@MoS2/hydroxyapatite/ZIF8 self-assembled nanohybrid for designing multi-functional smart anti-corrosion system

For the first time, a three components hybrid nanomaterials consisting of molybdenum disulfide (MoS2), hydroxyapatite (HAp), and zeolitic imidazolate framework8 (ZIF8) was utilized as a novel nanocontainer to build a smart anti-corrosion epoxy coating (Ep coating). This nanocontainer was loaded with Benzotriazole (BTA) to impart self-healing properties to the Ep coating and increase its durability against corrosion. To ensure that the filler was effectively synthesized, characterization tests including X-ray diffraction, FT-IR, BET, and TGA were conducted. EIS and polarization tests, conducted on the extract solution of BTA@MoS2/HAp/ZIF8, showed it had a high potential for reducing the corrosion of metals with a mixed inhibition mechanism. The EIS outcomes for the intact coatings suggested that an Ep coating's lifespan increased by including BTA@MoS2/HAp/ZIF8. Even after seven weeks of immersion in a 3.5% NaCl solution, it was able to keep |Z|f = 0.01Hz above 109.5. FE-SEM and EIS experiments revealed that the Ep coating filled with BTA@MoS2/HAp/ZIF8 exhibited self-healing properties after an artificial scratch creation. Incorporating BTA@MoS2/HAp/ZIF8 into the Ep coating enhanced the coating's adhesion properties and lowered adhesion loss by 78.4%. BTA@MoS2/HAp/ZIF8 could also reduce the diameter of cathodic disbondment by 68%.