In this study, the influence of manganese versus carbon (Mn/C) mass ratio on the impact toughness of high strength low alloy (HSLA) steel containing Ti-Ca-Al oxide particles was investigated. The results indicated that the dominant Ti-Ca-Al-O-MnS/TiN particles in steels with three Mn/C ratio promoted the formation of acicular ferrite (AF). In the 0.13C-1.65Mn steel (Mn/C approximate to 13), a relatively high carbon content promotes the formation of pearlite and carbides, but its microstructure is still mainly AF, accompanied by some polygonal ferrite (PF). When the carbon content was reduced to 0.07 wt% (Mn/C approximate to 24), carbides were no longer observed. A fine AF microstructure predominated, characterized by high-angle grain boundaries and a high density of dislocations. Furthermore, in the 0.06C-2.55Mn steel (Mn/C approximate to 43), granular bainite (GB) and martensite-austenite (M-A) were observed, and AF nucleation was limited due to the combined effects of ultra-low C content and high Mn content. The impact toughness of HSLA steel containing Ti-Ca-Al oxides with Mn/C ratios of 13, 24, and 43 is similar to 111 J, similar to 213 J, and similar to 35 J at 0 degrees C, respectively. At -20 degrees C, the steel with a Mn/C ratio of 24 still exhibited high impact toughness (similar to 160 J), which is 5.7 and 11.4 times higher than those of the steels with Mn/C ratios of 13 and 43, respectively. This study provides an effective method for further microstructure refinement and toughness improvement of hot-rolled HSLA steels.

Low-cost organic photodetectors (OPDs) based on intermolecular charge transfer (CT) absorption can significantly extend the response spectrum into the near-infrared (NIR) range. However, due to the weak CT absorption, the external quantum efficiencies (EQE) are typically very low in the NIR region. In this work, a photomultiplication OPD (PM-OPD) is developed by introducing a C60:MoO3 multiplication layer, which significantly enhances the EQE of NIR OPDs based on CT absorption. Unlike PM-OPDs that rely on unbalanced donor-acceptor ratios, our strategy preserves CT absorption efficiency. The highest occupied molecular orbital energy level of MoO3 traps photogenerated holes under forward bias, leading to band bending near the Al cathode and facilitating electron injection from the external circuit. Under a forward bias of 15 V, the EQEs exceed 100 % across the wavelength range from 300 nm to 1100 nm, with the EQE reaching an extraordinary 177,236 % at 420 nm. The responsivity and detectivity at 500 nm achieve maximum values of 628 A W- 1 and 1.49 x 10 1 3 Jones, respectively. Under 1000 nm NIR light excitation, EQE reaches 754 %, with corresponding responsivity and detectivity of 6.08 A W- 1 and 1.44 x 10 1 1 Jones. Under reverse bias, the device functions as a photodiode, with no photomultiplication occurring. Our device can respond to NIR light up to 1208 nm under both forward and reverse biases. This work contributes to the development of low-cost, high-performance NIR OPDs.

In this study, Ti and Nb elements were further added to the 125 ksi grade oil casing steel containing V element to study the precipitation behavior of carbides and the change of hydrogen embrittlement sensitivity under the condition of composite precipitation. The carbide precipitation of Ti/V and Nb/V during the quenching and tempering process and its effect on the hydrogen embrittlement sensitivity of the stress rupture test ( SSRT) were studied by means of microstructure and properties analysis and hydrogen embrittlement sensitivity test. The results show that Ti/V can effectively refine the size of the precipitated phase, and Nb/V can reduce the dislocation density, reduce the proportion of high angle grain boundaries, and increase the proportion of & sum;3 grain boundaries, thereby reducing the hydrogen embrittlement sensitivity of the material.

Manipulating oriented electron flow and tailored reaction microenvironments in radial-unguided two-dimensional phosphorene remains challenging. Here, we show that Rh-decorated violet/black phosphorus heterostructures, engineered with integrative dual-electric fields from cooperative phase and fringing electric field, enable efficient vapor-fed photocatalytic hydrogen production. This dual-electric field establishes a strong intrinsic charge driving force and edge charge ordering. The vapor-fed gas-solid system minimizes interfacial diffusion barriers and solvent shielding, allowing the field to steer photoelectrons and interact with H2O molecules at the edge-located Rh active centers. Analyses reveal that the integrative dual-electric field strengthens polarization and overcomes the water dissociation barrier at the gas-solid interface. The optimized catalyst achieves a H2-generation rate of 5218.7 μmol g-1 h-1 under simulated sunlight, roughly 2.4 times conventional liquid-solid systems. This work demonstrates that synergy between integrative dual-electric fields and the gas-solid microenvironment overcome the kinetic limitations of phosphorene-based photocatalysts for efficient solar-driven hydrogen conversion.

Alkaline water electrolysis is a promising pathway for large‐scale hydrogen production, yet its efficiency is limited by the sluggish kinetics of the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, a bifunctional CoFeP electrocatalyst is reported featuring a crystalline/amorphous heterostructure with engineered built‐in electric fields (BEFs). The integration of crystalline CoP and Fe 2 P domains with amorphous regions induces interfacial charge redistribution, driven by work function differences, which in turn generates BEFs that modulate the electronic structure and optimize the d‐band center. This tuning enhances the adsorption/desorption energetics of reaction intermediates, thereby boosting catalytic performance. As a result, CoFeP delivers low overpotentials of 199 mV for HER and 329 mV for OER at 1 A cm −2 in 1 m KOH. Remarkably, the catalyst exhibits outstanding durability over 1500 h under industrially relevant conditions (6 m KOH, 80 °C, 0.5 A cm −2 ). Technoeconomic analysis estimates a hydrogen production cost of $1.10 per gasoline gallon equivalent, significantly below the U.S. DOE's 2026 target. A rational design strategy is offered here for interface and electronic structure engineering and a viable platform is presented for next‐generation industrial water electrolysis.

Marine engineering projects have increasing requirements for ship plate steel, which needs high toughness and strength. The heat treatment after rolling will significantly affect the microstructure and low-temperature toughness of the ship plate steel. To study the effect of tempering temperature on the microstructure and low-temperature toughness of ship plate steel, the effects of tempering temperature from 475 to 595 °C on microstructure transformation, impact toughness, and Vickers hardness of 16-mm-thick hot-rolled ship plate steel of Ti-Zr deoxidation treatment were analyzed. The results show that the microstructures of hot-rolled steel plates tempered at 475, 535, and 595 °C are mainly ferrite, bainite pearlite, partially undecomposed martensite austenite (M/A) constituent, and inclusion. As the tempering temperature increases, the M/A constituent and pearlite are refined and decomposed. However, the ferrite grain is slightly coarsened, and the microstructure homogenization improves the toughness of the low-temperature impact. Ti-Zr deoxidized steel tempered at 535 °C for 35 min shows the highest impact toughness, about 57 J at − 20 °C, by GB/T 712-2022. Tempering reduces the dislocation density and decreases the hardness from HV217 to HV189. The appearance of parallel bainite in the experimental steel after tempering at 595 °C reduces the toughness of the experimental steel. The inclusions in the steel are mostly composed of Ti, Zr, O, and Mn elements, and the composite oxide particles promote the formation of acicular ferrite.

In this study, the influence of incorporating equimolar proportions of vanadium, titanium, and niobium microalloying elements into C110 steel on the hydrogen embrittlement susceptibility of oil casing steel was investigated at a strength level of 125 ksi. Experimental analyses including microstructural assessment and hydrogen permeation testing were performed to examine the impact of vanadium, titanium, and niobium microalloying elements on the stress-sustained rupture testing (SSRT) hydrogen embrittlement fracture behavior of the steel. It was demonstrated that the incorporation of vanadium microalloying elements at equimolar proportions predominantly enhances the presence of irreversible hydrogen trapping sites, enhances the resistance to tempering softening, and ultimately augments the hydrogen embrittlement resistance of the material.

Diamond-like carbon (DLC) film are solid lubricating materials composed of sp(2) / sp(3) carbon hybrids. They have the advantages of high hardness, wear resistance, long life, good chemical stability, easy access to atomically smooth surfaces, and an adjustable composition and structure. They can achieve low friction or even super-lubricity (friction factor <0.01) under atmospheric and heavy load conditions and are expected to be applied to traditional aero-engine systems. However, the high internal stress in DLC films makes it subjected to failure by film delamination under complex loading conditions during friction, which restrict its application in aero-engines and the service life of aviation equipment. To address these issues, current studies have been undertaken by adopting doping, multi-layer structures, and nitriding / coating composite surface treatments, which improve the film performance on one hand but may undermine the overall performance of film / substrate. For instance, doping reduces the internal stress while degrading mechanical properties of the DLC, whereas high-temperature nitriding degrades the performance of aero-engine gear steel substrates. A proper interlayer structure design can improve the film / substrate adhesion and bridging the gaps in the mechanical properties between the substrate and film, which would alleviate film internal stress and enhance the overall tribological performance. To provide a guideline for the application of solid lubricating films in aviation equipment, we investigate the effect of different interlayers on tribological properties of carbon films and ion-infiltrated composite carbon films in this study. A series of hydrogenated carbon films with multi-layer structures are prepared on a Si substrate using medium-frequency magnetron sputtering. The structure, surface morphology, and mechanical and tribological properties of TiSi / TiSiN / TiSiC / a-C:H films are evaluated using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), Raman spectroscopy, nanoindentation, surface profilometry, and friction testing. The results show that the deposition rate of the hydrogenated carbon films increases with an increase in the nitrogen content in the interlayer. The optimal hydrogenated carbon film has the highest hardness of 15.50 GPa with lowest residual stress (-0.5 GPa), strongest binding force (13.4 N), the lowest wear rates of 1.8x10-8 mm(3) / (Nm). Compared with the nitrogen-free DLC, the nitrogen doped samples have higher hardness and good anti-friction and wear resistance, indicating that the addition of the intermediate TiSiN layer can improve the mechanical and tribological properties of the a-C:H film. Microstructure analysis show that TiSi / TiSiN / TiSiC / a-C:H film promote the graphitization process from sp(3) to sp(2) during friction, which is beneficial for reducing friction and the wear rate. These results provide technical basis for preparation of wear-resistant DLC multi-layer films on aviation gear steel substrates.

To enhance the wear resistance of cobalt/chromium/iron/nickel (CoCrFeNi) coating, CoCrFeNiMo high entropy alloy coatings (HEACs) was developed using laser directed energy deposition (LDED). The both HEACs are metallurgically bonded to the substrate. Compared with CoCrFeNi, the CoCrFeNiMo coating presented X-ray diffractometer (XRD) diffraction peaks of Mo-rich sigma and mu phases, and the microstructure was significantly refined, with the maximum grain size reduced by 27.13% and the average grain size decreased by 83.87%. Compared to CoCrFeNi, under a 10 N load, the CoCrFeNiMo coating reduced the average friction coefficient and wear volume from 0.585 to 0.379 and 0.01825 mm3 to 0.0064 mm3. Even under a load of 15N, the friction coefficient and wear volume of CoCrFeNi coating are still approximately 1.46 and 1.72 times that of CoCrFeNiMo coating, respectively. In contrast to the adhesive and oxidative wear observed in CoCrFeNi coating, CoCrFeNiMo coating primarily exhibit abrasive wear and minor oxidative wear. These findings emphasize the significant potential of Mo-rich HEACs in reducing wear.

The microstructure and wear behavior of laser cladding FeCoCrMoNi high-entropy alloy (HEA) coating on Q235 steel substrate were studied. The coatings consisted of an FCC matrix, σ precipitates, and μ precipitates. With increasing heat treatment temperature, the μ phase precipitated and grew from the interdendritic σ phase, while the tip σ phase also precipitated from the FCC matrix. The number of dual precipitates reached its peak at 850 °C. Further, an increase in heat treatment temperature led to the replacement of the interdendritic σ phase by μ phase. The wear resistance of the coatings was closely related to the microstructural evolution. That is, the strengthening effect of the precipitated phase improved the wear resistance. The wear resistance of the coatings initially decreased and then, increased with increasing heat treatment temperature. At 850 °C, the coating has the best wear resistance due to its lowest wear rate, surface roughness and friction coefficient. The dominant wear mechanism being abrasive wear.

Renewable energy technologies have been continuously improved as a result of the pressing need for sustainable energy. Among these, hydrogen energy has received widespread attention from scientific researchers because of its clean, eco-friendly, and high energy density. Electrocatalytic water splitting for hydrogen production, especially at high current densities (HCD), is seen as a key approach to reshape the global energy landscape and achieve carbon neutrality. Therefore, finding cost-effective electrocatalysts with excellent activity and stability under HCD is important for large scale water splitting. Layered double hydroxides (LDHs) are highly recognized as promising electrocatalysts due to their unique two-dimensional molecular layered structure, high structural regulability, and readily available raw materials. In this review, we outline the fundamental principles of water electrolysis in alkaline water/seawater environments, analyzing the necessity for catalysts in HCD designs. We then delve into innovative approaches of LDH electrocatalysts for HCD alkaline water splitting. Lastly, we present an overview of the challenges and opportunities associated with HCD alkaline seawater electrolysis.

Heterostructures are widely employed in photocatalysis to promote charge separation and photocatalytic activity. However, their benefits are limited by the linkages and contact environment at the interface. Herein, violet phosphorus quantum dots (VPQDs) and graphitic carbon nitride (g-C3N4) are employed as model materials to form VPQDs/g-C3N4 heterostructures by a simple ultrasonic pulse excitation method. The heterostructure contains strong interfacial P-N bonds that mitigate interfacial charge-separation issues. P-P bond breakage occurs in the distinctive cage-like [P9] VPQD units during longitudinal disruption, thereby exposing numerous active P sites that bond with N atoms in g-C3N4 under ultrasonic pulse excitation. The atomic-level interfacial P-N bonds of the Z-scheme VPQDs/g-C3N4 heterostructure serve as photogenerated charge-transfer channels for improved electron-hole separation efficiency. This results in excellent photocatalytic performance with a hydrogen evolution rate of 7.70 mmol g-1 h-1 (over 9.2 and 8.5 times greater than those of pure g-C3N4 and VPQDs, respectively) and apparent quantum yield of 11.68% at 400 nm. Using atomic-level chemical bonds to promote interfacial charge separation in phosphorene heterostructures is a feasible and effective design strategy for photocatalytic water-splitting materials.

Study on the synthesis and applications of N-confused porphyrin manganese, iron and cobalt complexes has become one of the hot topics of porphyrin chemistry. Compared with the coordination chemistry of porphyrin, that of N-confused porphyrin is complicated because of the peripheral nitrogen atom, the intramolecular C-H bond and NH tautomerism. N-confused porphyrin has two NH tautomers, isomer A and isomer B. Varied functions are observed in the coordination chemistry of N-confused porphyrin such as stabilization of unusual metal oxidation states and metal-carbon bond formation. N-confused porphyrins have flexible character toward the metal oxidation state. Removal of the number of hydrogen atoms from one to three will result in a monanionic, dianionic and trianionic macrocycle. The various metal oxidation states are observed in N-confused porphyrin manganese, iron and cobalt complexes. The monovalent character of N-confused porphyrin is observed in cobalt chemistry such as Co-II(2-N-RNCTPP)Cl and Co-II(NCTPP). The cobalt metal takes a valence of +2 since Co-II(2-N-RNCTPP)Cl has a monoanionic axial ligand and N-confused porphyrin ligand. The squar-planar Co(II) complex Co-II(NCTPP) exists the cobalt-carbon bond. The divalent and trivalent characters of N-confused porphyrins are observed in manganese, iron and cobalt chemistry. In Mn(III) and Fe(III) complexes of N-confused porphyrin Mn-II(NHCTPP)Br and Fe-II(NHCTPP)Br, oxidation of the metal center is observed through intramolecular C-H bond activation of N-confused porphyrin ligand, which can be converted into Mn(III) and Fe(III) complexes Mn-III(NCTPP)Br and Fe-III(NCTPP)Br on exposure to air in solutions. {FeNO}(6) with a linear Fe-NO conformation is observed in the iron chemistry of N-confused porphyrin, which is unusually stable among the porphyrin iron nitrosyl complexes. It implies that iron N-confused porphyrin complexes can be used to study NO delivery and storage. This review covers the progress on the synthesis of N-confused porphyrin manganese, iron and cobalt complexes and their applications in the field of catalytic chemistry and biological chemistry. The synthesis methods of N-confused porphyrin manganese, iron and cobalt complexes and their applications in catalytic oxidation, cyclopropanation of alkene, nitrate reductase activity and chemical nuclease activity are introduced systematically.

The electrocatalytic hydrogen evolution performance of FeCoNiCrMo high-entropy alloy (HEA) coating with different porosity prepared by plasma spray was investigated in this study. The feedstock powder is prepared by atomization method and mechanically mixed with an additional content of Al powder. The plasma spray prepares the mixture coatings on the Cu substrate. The porous electrocatalytic electrodes are obtained by the dealloying method. The porous HEA electrodes present the major FCC phase, the phase FeCrNiMo, and the phase Al2O3, wherein the Al2O3 formed due to the residual of the Al element. The oxides on the surface composed of Fe2O3, FeO, Co2O3, CoO, NiO, Ni2O3, Cr2O3, MoO2, and MoO3. Adding Al content increases the porosity, approaching 13.19

The development of efficient, durable, and affordable electrocatalysts is critical for the advancement of a hydrogen economy, particularly in alkaline media. In this study, we propose CoCrFeNi and CoCrFeNiMo high entropy alloys (HEAs) powders as bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). While there is a performance gap compared to Pt/C, the prepared samples exhibit relatively good electrocatalytic activity with overpotentials of 156.7 mV and 160.5 mV for HER at 10 mA cm-2 in a 1.0 M KOH solution, respectively. Notably, the CoCrFeNiMo catalyst demonstrates significantly higher OER activity than commercial RuO2 with an overpotential of 390 mV at 50 mA cm-2 , and delivers a cell voltage of 1.86 V at a current density of 10 mA cm-2 for water splitting.

Nitrogen oxides (NOx) pollutants can cause a series of environmental issues, such as acid rain, ground-level ozone pollution, photochemical smog and global warming. Photocatalysis is supposed to be a promising technology to solve NOx pollution. Graphitic carbon nitride (g-C3N4) as a metal-free photocatalyst has attracted much attention since 2009. However, the pristine g-C3N4 suffers from poor response to visible light, rapid charge carrier recombination, small specific surface areas and few active sites, which results in deficient solar light efficiency and unsatisfactory photocatalytic performance. In this review, we summarize and highlight the recent advances in g-C3N4-based photocatalysts for photocatalytic NOx removal. Firstly, we attempt to elucidate the mechanism of the photocatalytic NOx removal process and introduce the metal-free g-C3N4 photocatalyst. Then, different kinds of modification strategies to enhance the photocatalytic NOx removal performance of g-C3N4-based photocatalysts are summarized and discussed in detail. Finally, we propose the significant challenges and future research topics on g-C3N4-based photocatalysts for photocatalytic NOx removal, which should be further investigated and resolved in this interesting research field.

Two-dimensional (2D) Nb-based oxynitrides are promising visible-light-responsive photocatalysts for the water splitting reaction, but their photocatalytic activity is degraded by the formation of reduced Nb5+ species and O2− vacancies. To understand the influence of nitridation on the formation of crystal defects, this study synthesized a series of Nb-based oxynitrides through the nitridation of LaKNaNb1−xTaxO5 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0). During nitridation, K and Na species volatilized, which helped transform the exterior of LaKNaNb1−xTaxO5 into a lattice-matched oxynitride shell. Ta inhibited defect formation, yielding Nb-based oxynitrides with a tunable bandgap between 1.77 and 2.12 eV, straddling the H2 and O2 evolution potentials. After loading with Rh and CoOx cocatalysts, these oxynitrides exhibited good photocatalytic activity for H2 and O2 evolution in visible light (650–750 nm). The nitrided LaKNaTaO5 and LaKNaNb0.8Ta0.2O5 delivered the maximum H2 (19.37 μmol h−1) and O2 (22.81 μmol h−1) evolution rates, respectively. This work provides a strategy for preparing oxynitrides with low defect densities and demonstrates the promising performance of Nb-based oxynitrides for water splitting.

Dual or multi-phase high-entropy alloys (HEAs) with nano-precipitates are of great importance to overcome the strength-ductility tradeoff of structural materials. In this work, Al0.5CrFeNi2.5Si0.25 HEAs were designed and fabricated using vacuum induction melting. The microstructure, phase evolution and compressive behavior of Al0.5CrFeNi2.5Si0.25 HEAs before and after annealing at various temperatures (750 degrees C, 850 degrees C, 1050 degrees C, and 1200 degrees C) were investigated. The as-casted and annealed Al0.5CrFeNi2.5Si0.25 HEAs constitute a dual-phase (FCC and BCC) composition with L12 and sigma phases. With increasing annealing temperature (750 degrees C-1200 degrees C), the proportion of the BCC matrix containing Cr-rich nanoparticles and strip-shaped sigma phases gradually increased. The Cr-rich nanoparticles were gradually refined. Partial sigma phase dissolved after heat treatment at 1050 degrees C and 1200 degrees C. The variation of the precipitated phases at different temperatures led to the occurrence of strengthening, which makes the alloys overcome the tradeoff between compressive strength and ductility. Under the 750 degrees C-1200 degrees C annealing, the compressive strength increased from 2288 MPa to 2584 MPa, accompanied by an increase in fracture strain from 14.9% to 23.4%.

A feasible method of enhancing the impact toughness (-20 degrees C) of high-temperature hot-rolled HSLA steels was proposed. The results show that the toughness of the improved hot-rolled steel containing TiOx-CaO-ZrO2 oxide particles was significantly enhanced by -132 J compared with conventional steel containing Al-Ca oxide particles. The fine (Ti, Ca, Zr) Ox particles with high-density of -937 counts/mm2 significantly promotes anticracking acicular ferrite (AF) nucleation. Moreover, the fractional volume of AF increased from -79 % to -85 % when the rolling temperature was increased from -1055 degrees C to -1085 degrees C.