The optimisation of sacrificial anode activity is critical for the viability of sustainable deep-sea equipment applications. This study investigates the effects of highly active Li on the phase constitution and electrochemical behaviour of Zn-xLi alloys in seawater. Appropriate Li addition induces reversible Zn/beta-phase transformation, refines the microstructure and forms micro-/nano-scale galvanic couples, ultimately enhancing charge-transfer kinetics. The porous, flake-like ZnO corrosion layer formed on the Zn-Li alloys facilitates electrolyte penetration, and preferential beta-phase dissolution creates a lamellar matrix surface, expanding the fresh reactive interface of the alloys. Furthermore, density functional theory analysis confirms that Li dissolution increases the (0001)Zn surface energy, thereby enhancing the electrochemical activity of the alloy matrix.

The corrosion resistance of titanium alloys in marine environments can be compromised by sulfate-reducing bacteria (SRB), yet it remains unclear whether alloy design principles established in abiotic media remain applicable under microbiologically active conditions. This study investigated the microbiologically influenced corrosion (MIC) behavior of three titanium alloys with different phase constitutions and alloy chemistries: β-type Ti-18Mo, α + β-type Ti-62A, and α-type Ti-6Al, following exposure to Desulfovibrio desulfuricans. A clear resistance hierarchy was observed: Ti-18Mo > Ti-62A > Ti-6Al. The results indicate that this hierarchy arises from the coupled effects of phase constitution, alloying chemistry, and passive-film stability. Sulfide-associated surface species detected after SRB exposure were accompanied by pronounced changes in passive-film chemistry, consistent with sulfide-associated modification of the passive film. Ti-18Mo exhibited the highest resistance, together with a comparatively greater TiO2-related contribution after prolonged Ar+ sputtering and the lowest donor density. These findings indicate that the observed MIC resistance is governed by the combined influence of microstructural characteristics and alloy-dependent passive-film chemistry, highlighting both factors as important considerations in the design of titanium alloys for SRB-containing marine environments.

Carbamate pesticides are crucial for enhancing crop production and ensuring food security, while their residues pose a significant risk of environmental contamination, the effective removal of carbamate pesticide residues is essential. Herein, a magnetic three-dimensional network structure hydrogel adsorbent was prepared by inverse suspension polymerization of hydrophilic vinyl monomers, modified with attapulgite and Fe3O4. This adsorbent had a strong adsorption capacity and was easy to recycle. The inverse phase suspension polymerization method has the advantages of a stable polymerization process, products need not be crushed, and it is easy to dry. In this paper, acrylic acid (AA) was used as the monomer, and a certain amount of activated attapulgite (ATP) was added. The magnetic PAA hydrogel was prepared by the inverse suspension phase polymerization method, and its structure and surface properties were examined using scanning electron microscopy (SEM), Brunauer-Emmet-Teller (BET), X-ray diffraction (XRD), and Fourier transform infrared (FTIR). On this basis, the magnetic PAA hydrogel's adsorption of carbamate pesticides was evaluated by isothermal and kinetic adsorption models. The adsorption behavior of pirimicarb on the magnetic PAA hydrogel adhered to the Freundlich model and pseudo-second-order kinetics, at an initial pirimicarb concentration of 20 mg & centerdot;L-1, the adsorption reached 97.25% within 60 min. The manuscript could provide certain research ideas and technical supports for advanced treatment of pesticide-contaminated wastewater.

This study presents a novel photo-driven selective oxidation (PDSO) strategy for the synchronous modulation of surface structure and SO4 2- group anchoring in In2S3/MgIn2S4 (IS/MIS) heterostructure. Gradient sulfur vacancies were first engineered via hydrothermal synthesis and annealing to direct hole migration. Subsequently, a photo-assisted chronoamperometric treatment was employed to selectively oxidize S2- to SO4 2-, which concurrently triggered Mg2+ leaching and surface reconstruction. This dual modulation resulted in an over 200% expansion of the electrochemical active surface area and the effective anchoring of SO4 2- species, which effectively promoted the participation of photogenerated holes in interface redox reactions via surface trap states. The optimized selective oxidation of rearranged-Sv IS/MIS (SO-R-IS/MIS) photoanode exhibited a remarkable 410 mV negative shift in onset potential (to 0.24 V vs. RHE) and delivered a photocurrent density of 7.8 mA cm-2 at 1.23 V vs. RHE. This work establishes a paradigm for precision surface engineering of photoanodes via photo-driven selective reconstruction.

In this paper, the corrosion behavior of 304 stainless steel was investigated in the tidal zone of South China Sea through the field exposure tests. Results reveal that specimens exposed for 0.5 years exhibit minimal corrosion, with surfaces predominantly covered by algae, calcium-magnesium deposits, and barnacle. With prolonged exposure, the number of barnacles attached increases and occluded corrosion micro-cells are formed on the attachment zone, aggravating the localized corrosion condition. Electrochemical results show that specimen exposed for 0.5 years has a self-corrosion potential of -0.07 V (vs. SCE), while that for two years shifts negatively to -0.15 V accompanying a self-corrosion current density increase from 1.91 × 10–8 A cm−2 to 3.89 × 10–8 A cm−2. With prolonged exposure, barnacle attachment increases progressively, reaching 30

Hypereutectic Zn-Li alloys are a kind of high-strength biodegradable Zn alloys developed in recent years. However, they exhibit significant hot-rolling brittleness. The higher rolling temperature and the larger volume fraction of the brittle blocky β phases result in cleavage fracture easily. After warm rolling, the alloys become very ductile with dimple fracture. Abnormally, when the volume fraction of brittle β-LiZn4 phase in alloys increases from 38.9 to 61.4 vol.

The mechanism of microbiologically influenced corrosion (MIC) of titanium alloys in anaerobic marine environments remains poorly understood, particularly after the protective passive film is compromised. In this study, the MIC mechanism of Ti-6Al-4V induced by Desulfovibrio bizertensis SY-1 was systematically investigated. Anaerobic exposure promoted oxygen-vacancy formation in the passive film and facilitated biogenic sulfide ingress into the oxide layer. The resulting deterioration of barrier integrity generated electrochemically active sites for interfacial cathodic reactions. Under 10% carbon-source starvation condition, the pit depth and corrosion current density increased by 1.9 and 2.5 times, respectively, indicating that D. bizertensis SY-1 could uptake electrons from the alloy to sustain metabolism. In addition, hydrogenase-related genes were significantly upregulated, accompanied by an approximately one-order-of-magnitude increase in hydrogenase activity in the cell-free filtrate. Extracellular hydrogenases released by D. bizertensis SY-1 catalyzed proton reduction on passive‑film‑compromised Ti‑6Al‑4V, generating H2 that subsequently served as the diffusible electron carrier for intracellular sulfate reduction and cell growth. In contrast, hydrogenase inactivation nearly abolished electron acquisition from the alloy and drastically reduced metal ion release. These results indicate that passive-film degradation and extracellular hydrogenase activity act sequentially to enable D. bizertensis SY-1 to acquire electrons from Ti-6Al-4V, with H2 serving as a major intermediary electron carrier. This hydrogenase-dependent electron acquisition pathway provides a mechanistic explanation for the severe MIC of passive titanium alloys induced by SRB under anaerobic and nutrient-limited marine conditions.

This study reports a cyano group-bridged strategy to construct a stable Z-scheme heterojunction (Cy-CN/Ag/ AgVO3) for efficient tetracycline degradation. Cyano-functionalized g-C3N4 (Cy-CN) was synthesized via KBr cocalcination followed by N2-atmosphere secondary calcination, providing anchoring sites for Ag+ . Through strong coordination between cyano-N atoms and Ag+, ultrafine Ag quantum dots were in situ anchored, followed by hydrothermal growth of AgVO3. The optimized Cy-CN/Ag/AgVO3 achieved a tetracycline degradation rate of 0.015 min-1-three times higher than that of pristine g-C3N4. Mechanistic studies revealed a Z-scheme charge transfer pathway mediated by Ag, which enhances the separation efficiency of photogenerated carriers while preserving their high-energy states-key factors contributing to the superior photocatalytic performance. This work highlights cyano group-directed interfacial engineering as a promising paradigm for designing highefficiency metal-semiconductor photocatalysts.

Deep eutectic solvent (DES)-based conductive hydrogels have attracted great interest in the building of flexible electronic devices that can be used to replace conventional temperature-intolerant hydrogels and expensive ionic liquid gels. However, current DES-based conductive hydrogels obtained have limited mechanical strength, high hysteresis, and poor microdeformation sensitivity of the assembled sensors. In this work, a rubber-like conductive hydrogel based on N-acryloylglycinamide (NAGA) and DES (acetylcholine chloride/acrylamide) has been synthesized by a one-step method. The prepared conductive PNAGA-DES hydrogel has exhibited excellent mechanical strength, stability, and resilience during the long-term loading-unloading cycles, endowed with service durability. Besides, the as-prepared PNAGA-DES also possesses high transparency, high conductivity, and favorable antienvironmental disturbance, which can enhance the designability and robustness of the PNAGA-DES-based devices. Based on the remarkable properties, the PNAGA-DES hydrogel can be used for wearable pressure-strain sensors with high sensitivity of tiny strain for transferring information (gauge factor (GF) = 8.18, 0.2-2% strain) and long-term stability. Furthermore, it can also sensitively detect the large strain of human motion, showing potential application in information interaction and wearable electronics.

This study aims to mitigate the hydrogen embrittlement risk of marine high‐strength steel associated with cathodic protection anodes possessing negative working potentials. To achieve this, alloying elements with higher electrochemical potentials, specifically Ga, Sn, Sb, and Pb, are selected and incorporated into the Zn–Mn alloy to enhance its overall working potential. The addition of these elements to the Zn matrix results in the precipitation of secondary phases exhibiting potentials of 190–280 mV higher than that of the Zn matrix. The potential differences between these secondary phases and the matrix increase monotonically with the working potential of the Zn anodes. Furthermore, the incorporation of Sn, Sb, and Pb leads to a reduction in the current efficiency of the Zn alloys, dropping below 95.5%. This decline is attributed to the substantial volume and coarse morphology of the secondary phases, as well as the pronounced elemental segregation. In contrast, the inclusion of Ga refines the secondary phases, thereby preventing significant element segregation. Consequently, the Zn–Mn–Ga alloy demonstrates superior performance, exhibiting a current efficiency exceeding 98%, along with a working potential range between −0.93 and −0.82 V, which satisfies the cathodic protection potential requirements for high‐strength steel.

High-strength aluminum (Al) alloy is widely used in deep-sea equipment, and its corrosion problem is prominent. Coupling effect of electrochemical corrosion and pre-applied tensile stress on the performance degradation of high-strength Al alloy was investigated by means of microscopic morphology observation, micro area electrochemical testing, and corrosion product analysis. Results show that hydrostatic pressure and pre-applied stress significantly promoted corrosion of Al alloy in seawater, especially under high stress conditions. Additionally, external stress significantly increases the formation of protective film cracks and sensitivity to grain corrosion. There are significant differences in corrosion behavior and mechanical degradation performance under different stress conditions. Coupling effects lead to the decrement in mechanical properties and the enhancement of stress corrosion sensitivity of Al alloys.

Steel reinforcement undergoes passivation in the alkaline environment of concrete, resulting in the spontaneous formation and growth of a protective passive film. Understanding the growth pattern of passive films is crucial for enhancing the corrosion resistance of steel bars. This study investigates the impact of various electric potentials on passive film growth and its dynamic interaction with chloride ions. Furthermore, the behavior of the passive film after removal from the solution under different conditions is also examined. This study visually demonstrates the process of increasing the passivation potential of the passivation film and the degradation and thinning of the over-passivation potential. Chloride ions can significantly reduce the polarization potential and increase the degree of over-passivation degradation. After prolonged detachment from the solution, the integrity of the passivation film decreases. This study comprehensively evaluates the combined effects of external electric fields, the presence of chloride ions, and separation from an alkaline solution on the growth characteristics of the passive film.

Hydrogels are flexible materials characterized by a 3D network structure, which possess high water content and adjustable physicochemical properties. They have found widespread applications in tissue engineering, electronic skin, drug delivery, flexible sensors, and photothermal therapy. However, hydrogel networks often exhibit swelling behavior in aqueous environments, which can result in structural degradation and a loss of gel performance. In this study, polyacrylic acid is utilized as the primary network structure with the incorporation of the natural polymer chitosan. Furthermore, a conductive hydrogel exhibiting good mechanical strength similar to human skin and excellent anti-swelling properties is developed by integrating phytic acid into the hydrogel network. The as-prepared hydrogels exhibited maximum swelling in pure water, achieving an equilibrium swelling rate of 15%. Additionally, a dopamine-grafted polyacrylic acid binder is synthesized through a coupling reaction to enhance the adhesion of the hydrogels to various substrates. The hydrogels demonstrated strong adhesion properties with different substrates. Whether in the air or underwater, the hydrogel sensor effectively monitors human movement behaviors. Furthermore, by utilizing the sensing signals to send Morse code, the hydrogel sensor can facilitate underwater communication. This type of hydrogel sensor is anticipated to play a significant role in wearable sensing applications and underwater communication.

In this paper, the deep-sea galvanic corrosion behaviors of 10CrNi3MoV high-strength steel and 2205 stainless steel were used a high-pressure simulation device, and influence rules of hydrostatic pressure, temperature, and dissolved oxygen concentration were investigated. Results show the galvanic corrosion rate of the 10CrNi3MoV/2205 coupling initially increases, then decreases with the hydrostatic pressure increasing. The highest corrosion rate is 0.293 mm/a at 3 MPa, while the lowest rate is 0.173 mm/a at 6 MPa. Increases in both temperature and dissolved oxygen concentration lead to the higher galvanic corrosion process of the 10CrNi3MoV/2205 coupling, and furthermore result in the case that the corrosion pattern of 10CrNi3MoV high-strength steel transforms from the local corrosion to the uniform corrosion in the simulated deep-sea environment.

The corrosion and cavitation erosion (CE) behavior of Co-6Ti-11V-9Cr alloy are investigated in both deionized water and 3.5 wt.% NaCl solution. Utilizing electrochemical methods and CE testing, the research aims to clarify the synergistic effects of CE and corrosion. The results demonstrate that after 8 h of CE exposure, Co-6Ti-11V-9Cr alloy experienced a cumulative mass loss of 1.84 mg in deionized water and 3.42 mg in NaCl solution, leading to mass loss rates of 0.23 and 0.43 mg/h, respectively. In NaCl solution, CE was responsible for 53.8% of the overall damage, with the remaining damage attributed to the combined influences of corrosion and CE. Under CE conditions, both the corrosion potential and corrosion current density of the alloy increased, which accelerated the corrosion process and exacerbated cavitation damage. The material sustained more severe damage in 3.5 wt.% NaCl solution over the same cavitation durations. Ultimately, CE damage mechanism of Co-6Ti-11V-9Cr superalloy was elucidated based on relevant experimental observations.

Many special structures such as pipeline, revolving gears, and tanks suffer from biofouling used in marine environment, which could induce serious results in the ship system such as blockage and stuck, consequently lead to failure of the mechanical system and power system. Generally, coatings with antifouling agents are used for protecting metal structures from biofouling, but coatings are not conveniently applicable in the high velocity flowing seawater and narrow space. Electrochlorination and electrolysis of copper and aluminum anode are usually used in these circumstances, but the electric power will lead to stray current corrosion to the component. For the sake of convenience and safety, Cu-Ti pseudo alloy antifouling anode was proposed in this work for antifouling in pipeline and other narrow spaces without external electric power. Four Cu-Ti pseudo alloy antifouling anodes with different Ti contents (mass fraction) of 0 wt.%, 5 wt.%, 10 wt.%, and 15 wt.% were investigated with computational method, and a 15 wt.% Ti content Cu-Ti pseudo alloy antifouling anode was prepared by cold spray, and the microstructure and composition of the anode were observed by scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). Electrochemical tests were conducted to obtain the corrosion potential, potentiodynamic polarization curve, and micro zone electrochemical information in natural seawater, and the Cu ions releasing behavior were analyzed using inductively coupled plasma (ICP). The results indicated that in natural seawater, copper particles, and titanium particles on the surface of anode samples can form micro galvanic couples. With the increase in Ti mass fraction, the number of micro primary cells composed of copper particles and titanium particles increases, and the corrosion rate of Cu particles increased. When the Ti mass fraction is 15%, the corrosion rate is the fastest, and the copper ion release rate increases by nearly ten times, reaching 147 μg/(cm2·d). This method can effectively accelerate the releasing rate of Cu ions in Cu-Ti pseudo alloy anode and promote the antifouling effect.

The stress-electrochemical corrosion behavior of high-strength aluminum alloy welded joints in simulated deep-sea environment was investigated in this paper. The corrosion morphology, electrochemical characteristics and mechanical behavior of aluminum alloy welded joints in deep sea were studied under different stress levels and immersion time. The corrosion characteristics were analyzed by electrochemical testing, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), and the corrosion mechanism of welded joints was revealed. It is found that hydrostatic pressure and pre-applied stress significantly promote the corrosion of materials in seawater. The corrosion of aluminum alloy welded joints is aggravated especially under high stress conditions. Additionally, the external stress significantly increases the corrosion rate and sensitivity of welded joints. There are significant differences in corrosion behavior and products under different stress conditions. The coupling effect of hydrostatic pressure and pre-applied stress leads to the decrease of mechanical properties and the enhancement of stress corrosion sensitivity of aluminum alloy welded joints.

Aqueous zinc metal batteries (AZBs), feature natural safety, economic viability, and eco-friendliness, are regarded as one of the best options for grid-scale energy storage. While, notorious adverse reactions (corrosion, hydrogen evolution reaction, Zn dendrites formation, and byproducts) induced by excessive active water molecules in aqueous electrolyte impede their practical application, which results in low utilization of Zn anode and awful cycle stability. In this work, a sustainable and recyclable cellulose gel electrolyte capable of limiting water molecules is developed to suppress the notorious adverse reactions and achieve the long-term stability of Zn anode. The Zn//Zn cell exhibits remarkable reversibility and stability at 5 mA cm- 2/2.5 mAh cm- 2 with the cellulose gel electrolyte, realizing 99.7 % coulombic efficiency and long lifespan of 680 h after 500 cycles, which is outperforming GF separator with aqueous electrolyte. The cellulose gel electrolyte also enables Zn// AC@MnO2 full cell to perform excellent rate performance and long-term cycling stability. More intriguingly, the used cellulose gel electrolyte can be regenerated to get a new one, recycled to produce electrode materials, and degraded in nature soil. This work promotes the green and sustainable development of AZBs practically.

Hydrogen peroxide (H2O2) is a highly value-added and environmental-friendly chemical with various applications. The production of H2O2 by electrocatalytic 2e- oxygen reduction reaction (ORR) has emerged as a promising alternative to the energy-intensive anthraquinone process. High selectivity Catalysts combining with superior activity are critical for the efficient electrosynthesis of H2O2. Earth-abundant transition metal selenides (TMSs) being discovered as a classic of stable, low-cost, highly active and selective catalysts for electrochemical 2e- ORR. These features come from the relatively large atomic radius of selenium element, the metal-like properties and the abundant reserves. Moreover, compared with the advanced noble metal or single-atom catalysts, the kinetic current density of TMSs for H2O2 generation is higher in acidic solution, which enable them to become suitable catalyst candidates. Herein, the recent progress of TMSs for ORR to H2O2 is systematically reviewed. The effects of TMSs electrocatalysts on the activity, selectivity and stability of ORR to H2O2 are summarized. It is intended to provide an insight from catalyst design and corresponding reaction mechanisms to the device setup, and to discuss the relationship between structure and activity.

The effect of sulfides on the pitting corrosion behavior and film chemistry of 70/30 copper-nickel alloys in aerated seawater was investigated. Sulfides in seawater prevent the formation of protective oxides on the surface of the alloy and alter the morphology and composition of the corrosion products. It results in the corrosion product film consisting of the double layer structure of the loose and porous sulfide-containing outer layer and the dense inner layer. This double-layer structure of the corrosion product film can’t alleviate corrosion, but instead accelerates the development of pitting corrosion. The statistical analysis method is used to study the corrosion process of 70/30 copper-nickel alloy in sulfide-containing environment. This work records the trend of pitting corrosion towards the horizontal and longitudinal directions.