One-step Annealing Research Articles

Nanocubic transition metal sulfides (FeMn)S2@NC synthesised by MOFs facily for supercapacitors

Transition metal sulfides have attracted considerable attention as supercapacitor materials due to their favorable electrochemical properties and low cost. However, challenges such as slow electrochemical kinetics and significant volume changes still persist. In this study, (FeMn)S2@NC nanocubes were synthesized by utilizing MOFs as precursors, employing a solution method to encapsulate Ppy around the periphery, followed by a one-step annealing process. The electrode prepared from (FeMn)S2@NC exhibits a high specific capacitance of 1154 F/g at 1 A/g and retains a specific capacitance of 777 F/g even at a high current density of 5 A/g. After 8000 charge-discharge cycles at 10 A/g, it still maintains a high capacity retention of 94% and close to 100% Coulombic efficiency. The (FeMn)S2@NC//AC capacitor exhibite excellent electrochemical performance with good rate capability and practical value 39.73F/g at 1A/g, 38.26F/g at 2A/g, 26.67F/g at 5A/g, 20.53F/g at 7A/g and 14F/g at 10A/g. Electrochemical testing at 5A/g show 93.3% high capacity retention after 180,000 cycles.

Influence of bottom supporting columns and cooling rate on the surface shape characteristics of sapphire substrates

The manufacturing process of sapphire substrates involves several key steps, including epitaxy, annealing, cutting, and processing. Among these, epitaxy and annealing are particularly crucial. The temperature variances along both the longitudinal and transverse axes within the furnace during the crystallization process play a significant role in determining the crystallization rate and internal structure of sapphire crystals. Furthermore, annealing sapphire serves to alleviate internal stress, enhance crystal structure, optimize physical properties, improve optoelectronic characteristics, enhance surface quality, and increase overall yield. This step is paramount in enhancing the performance and application value of sapphire materials. In order to investigate and optimize the effects of different thermal conductivities of support columns at the base and various annealing procedures on the surface characteristics of sapphire substrates, thereby improving product quality, this study conducted research by utilizing support columns made of different materials and carefully controlling the cooling rate parameters for sapphire. The findings revealed that using graphite as the base support column for the crystal furnace can reduce both the longitudinal and transverse temperature gradients within the furnace, consequently promoting crystal growth and enhancing the quality of sapphire ingots. Additionally, sapphire chips annealed using the rapid one-step annealing program exhibited the highest average warpage and bending rate variation, reaching 2.0 μm, and the average dislocation density was half that of conventionally produced chips, at 108.89 pits/cm2.

Grain Boundary Filling Empowers (002)-Textured Zn Metal Anodes with Superior Stability.

Aqueous Zn battery is promising for grid-level energy storage due to its high safety and low cost, but dendrite growth and side reactions at the Zn metal anode hinder its development. Designing Zn with (002) orientation improves the stability of the Zn anode, yet grain boundaries remain susceptible to corrosion and dendrite growth. Addressing these intergranular issues is crucial for enhancing the electrochemical performance of (002)-textured Zn. Here, a strategy based on grain boundary wetting to fill intergranular regions and mitigate these issues is reported. By systematically investigating boundary fillers and filling conditions, In metal is chosen as the filler, and one-step annealing is used to synergistically convert commercial Zn foils into single (002)-textured Zn while filling In into the boundaries. The inter-crystalline-modified (002)-textured Zn (IM(002) Zn) effectively inhibits corrosion and dendrite growth, resulting in excellent stability in batteries. This work offers new insights into Zn anode protection and the development of high-energy Zn batteries.

Microstructure Evolution and Tensile Properties of Medium Manganese Steel Heat Treated by Two-Step Annealing

In this paper, the nucleation and growth of austenite are controlled through a two-step annealing process to achieve multi-scale distribution and content increase of retained austenite in low manganese series medium-Mn steel. Combining SEM, EBSD, AES, and other experimental equipment, the evolution rules of the microstructure, properties, and element distribution behavior of the test steel during the annealing process are studied. Compared with one-step annealing, the two-step annealing significantly broadens the size distribution range of retained austenite. In the first step, after annealing at a higher intercritical temperature (760 °C), the ferrite and the M/A island are obtained, completing the initial partition of Mn and the refinement of microstructures. During the second step of annealing (720 °C), the primary Mn-rich martensite region provides higher nucleation driving force and finer dispersed nucleation sites, promoting the nucleation and growth of reverse transformation austenite. At the same time, the metastable-retained austenite formed after the first step of annealing continues to grow through interface movement. Furthermore, a high proportion (23.4%) of retained austenite with multi-scale distribution is formed in the final microstructure, and the product of strength and elongation increased from 21.8 GPa·% by the one-step annealing process to 30.1 GPa·%.

Hollow tubular MnOx prepared by flame annealing with cotton fiber as sacrificial template and its applications for Hg0 adsorption in flue gas

The mass discharge of mercury from coal-fired power plant has caused great harm, abating mercury emissions is of preoccupation for protecting public environmental safety and human health. Metal oxides are often used for Hg0 removal in the flue gas. In this paper, a hollow tubular MnOx(MnCot) was successfully prepared by rapid flame annealing using cotton fiber as a sacrificial template. The MnCot were then well characterized and tested for its capability for Hg0 removal in flue gas. The results indicate that the flame assisted synthesis method for rapidly prototyping metal oxides with typical structures is achievable. The hollow tubular structure of the cotton fiber is well reprinted with good crystallization of Mn3O4. The inner diameter of the hollow tubular MnCot is about 10 μm, and the thickness of the tube is about 1 μm. The Hg0 removal efficiency on MnCot can be maintained as high as 90 % under simulated flue gas atmosphere below 240°C. O2 and NO have a positive effect on the Hg0 removal, which can act as the fresh active sits thus enhancing its capability for Hg0 removal. However, the presence of SO2 will result in the surface sulfation on MnCot, thus deteriorating its capability for Hg0 removal. Further, the competitive adsorption between SO2 and Hg0 on the material will also weaken its capability for Hg0 removal. The hollow tubular MnOx rapidly prepared by one-step flame annealing has a good industrial application potential for Hg0 removal in coal-fired flue gas.

Oxygen vacancy-engineered P-doped MoO3/Ce2Mo4O15 bimetallic heterojunction nanosheet array for enhanced oxygen evolution reaction

Surface oxygen vacancies in defective metals have the capacity to enhance oxygen evolution reaction (OER) activity but easily suffer from instability and deactivation in continuous electrocatalysts. Heterojunction engineering is important for achieving effective catalysis, but its simultaneous engineering remains a challenge. Therefore, it is necessary to develop an effective heterojunction catalyst to improve the electrocatalytic stability of defective metallic oxygen vacancies. In this work, we report a Ce, Mo bimetallic defective heterojunction P-MoO3/Ce2Mo4O15@NF-1 via a facile one-step hydrothermal method and annealing in a tube furnace. Bimetallic oxide heterojunctions offer several advantages over conventional single-metal heterojunctions, including stable structure, more active sites, faster rates of electron transfer, and less pollution of the environment. Meanwhile, P-doped catalyst could enhance the metallicity significantly. In addition, the prepared catalyst P-MoO3/Ce2Mo4O15@NF-1 showed extraordinary catalytic activity for OER in alkaline media. The overpotential and Tafel slope of the catalyst at a current density of 50 mA cm-2 were 270 mV and 87.27 mV dec‑1, respectively. It maintains an impressive balance between electrocatalytic activity and stability. This research explores the co-effects of Ce and Mo bimetallic oxide in defective electrocatalysts and also provides ideas for designing OER catalysts with defective metal heterojunctions.

PtCo-ZIF-derived hybrid electrocatalysts comprising an ordered PtCo alloy and a single-atoms-decorated carbon shell for the oxygen reduction reaction

Recent research on hybrid catalysts showed that Pt-based alloy particles surrounded by a single-atoms-decorated carbon shell exhibit promising oxygen reduction reaction catalytic activity and durability owing to the synergistic effect. However, the structural complexity of these hybrid catalysts renders their synthesis challenging. This study synthesized a mixed-metal zeolitic imidazolate framework (ZIF) containing Pt and Co ions coordinated with a benzimidazole ligand, which was used as a scaffold to fabricate hybrid catalysts comprising uniform PtCo intermetallic alloy particles coated with a thin N-doped carbon shell containing numerous Pt and Co single atoms via one-step annealing. Without post-treatment, the mass and specific activities of the synthesized catalyst were significantly higher than those of the commercial Pt/C catalyst. Additionally, the synthesized catalyst exhibited ultra-long-term durability, meeting the 2025 target of the U.S. Department of Energy, even after 300 000 cycles of an accelerated durability test.

Boosting the activity for organic pollutants removal of In2O3 by loading Ag particles under natural sunlight irradiation

A novel photocatalyst In2O3 with loading Ag particles is prepared via a facile one-step annealing method in air atmosphere. The Ag/In2O3 exhibits considerable photoactivity for decomposing sulfisoxazole (SOX), tetracycline hydrochloride (TC), and rhodamine B (RhB) under natural sunlight irradiation, which is much higher than that of pristine In2O3 and Ag species. After natural sunlight irradiation for 100 min, 70.6% of SOX, 65.6% of TC, and 81.9% of RhB are degraded over Ag/In2O3, and their corresponding chemical oxygen demand (COD) removal ratio achieve 95.4%, 38.4%, and 93.6%, respectively. A batch of experiments for degrading SOX with adjusting pollutant solution pH and adding coexisting anions over Ag/In2O3 are carried out to estimate its practical application prospect. Particularly, the as-prepared Ag/In2O3 possesses a superior stability, which exhibits no noticeable deactivation in decomposing SOX after eight cycles’ reactions. In addition, the Ag/In2O3 coated on a frosted glass plate, also possesses a superior activity and stability for SOX removal, which solve the possible second pollution of residual powdered catalyst in water. Ag particles on In2O3 working as electron accepter improve charge separation and transfer efficiency, as well as the photo-absorption and organic pollutants affinity, leading to the boosted photoactivity of Ag/In2O3. The photocatalytic mechanism for degrading SOX and degradation process over Ag/In2O3 has been systemically investigated and proposed. This work offers an archetype for the rational design of highly efficient photocatalysts by metal loading.

The conductivity of Nb2O5 enhanced by the triple effect of fluorine doping, oxygen vacancy, and carbon modification for improving the lithium storage performance.

In view of the inherent pseudocapacitance, rich redox pairs (Nb5+/Nb4+ and Nb4+/Nb3+), and high lithiation potential (1.0-3.0V vs Li/Li+), Nb2O5 is considered a promising anode material. However, the inherent low electronic conductivity of Nb2O5 limits its lithium storage performance, and the rate performance after carbon modification is still unsatisfactory because the intrinsic conductivity of Nb2O5 has not been substantially improved. In this experiment, taking the improvement of the intrinsic electrical conductivity of Nb2O5 as the guiding ideology, we prepared F-doped Nb2O5@fluorocarbon composites (F-Nb2O5@FC) with a large number of oxygen vacancies by one-step annealing. As the anode electrode of lithium-ion batteries, the reversible specific capacity of F-Nb2O5@FC reaches 150 mA g-1 at 5Ag-1 after 1100 cycles, and the rate performance is particularly outstanding, with a capacity up to 130 mA g-1 at 16Ag-1, which is far superior to other Nb2O5@carbon-based anode electrodes. Compared with other single conductivity sources of Nb2O5@carbon-based composites, the electrical conductivity of F-Nb2O5@FC composites is greatly improved in many aspects, including the introduction of free electrons by F- doping, the generation of oxygen vacancies, and the provision of a three-dimensional conductive network by FC. Through analytical chemistry (work function, UV-Vis diffuse reflectance spectroscopy, and EIS) and theoretical calculations, it is proved that F-Nb2O5@FC has high electrical conductivity and realizes rapid electron transfer.

Microstructural Evolution and Mechanical Properties of V-Containing Medium-Mn Steel Adopting Simple Intercritical Annealing

The variations of the microstructure and mechanical properties of medium-Mn steel after vanadium (V) microalloying with different contents were investigated. After a one-step intercritical annealing (IA) at 730 °C, the steel containing 0.04 wt.% of V exhibited excellent comprehensive properties. The steel maintained an ultimate tensile strength (UTS) of 1000 MPa while also exhibiting a total elongation (TEL) of 37% and a product of strength and plasticity (PSE) of 37.7 GPa%. V-microalloying improved the yield strength (YS) and UTS of the experimental steel by refining ferrite grains and precipitation strengthening, however, it deteriorated its plasticity, which is difficult to compensate for through grain refinement and due to the TRIP effect of retained austenite (RA). The largest amount of RA and the appropriate stability also make a significant contribution to the outstanding UTS of the steel containing 0.04 wt.% of V through the TRIP effect. However, the further increase of V content led to decreased RA content and stability, weakening the TRIP effect and resulting in a weaker strength ductility balance.

Coupling iron-based zeolitic imidazolate Framework-8 and cellulose nanofiber for efficient peroxymonosulfate oxidation

The development of biocompatible Fenton-like catalysts with outstanding activities and stabilities, using low-cost sustainable bio-sourced materials, has garnered significant attention, yet remains a substantial challenge. In this study, we successfully constructed monodispersed iron anchored on a 3D porous N-doped carbon substrate (CNF@Fe-NC) via one-step annealing of Fe-based zeolitic imidazolate frameworks (ZIFs) and bacterial cellulose nanofibers (CNFs) as highly efficient peroxide-activation catalysts. Due to abundant micropores and mesopores in the interconnected CNF support and ZIFs, even after annealing, the obtained catalysts have a specific surface area of up to 739.4 m2/g. Owing to monodispersed Fe-Nx species and abundant nanofibrous structure, CNF@Fe-NC exhibited outstanding catalytic stability and superior activity for peroxymonosulfate (PMS) activation toward organic contaminant oxidation, outperforming the benchmark Fenton system. Surface Fe-Nx sites and CNF defects could adsorb negatively charged PMS to produce nonradical CNF@Fe-NC-PMS* complexes and high-valent iron oxo species (FeV = O), rather than radicals and 1O2, for eliminating pollutants. The strong iron − support electronic interaction and abundant π-conjugation in the CNF support facilitated the efficient adsorption and activation of PMS and the uniformly dispersed Fe species in CNF@Fe-NC improved atom-utilization efficiency. This study provides a clue to design biocompatible cellulosic-based Fenton-like catalysts for the removal of organic contaminants.

Patterned graphene oxide via one-step thermal annealing for controlling collective cell migration.

Graphene oxide (GO) is a two-dimensional metastable nanomaterial. Interestingly, GO formed oxygen clusterings in addition to oxidized and graphitic phases during the low-temperature thermal annealing process, which could be further used for biomolecule bonding. By harnessing this property of GO, we created a bio-interface with patterned structures with a common laboratory hot plate that could tune cellular behavior by physical contact. Due to the regional distribution of oxygen clustering at the interface, we refer to it as patterned annealed graphene oxide (paGO). In addition, since the paGO was a heterogeneous interface and bonded biomolecules to varying degrees, arginine-glycine-aspartic acid (RGD) was modified on it and successfully regulated cellular-directed growth and migration. Finally, we investigated the FRET phenomenon of this heterogeneous interface and found that it has potential as a biosensor. The paGO interface has the advantages of easy regulation and fabrication, and the one-step thermal reduction method is suitable for biological applications. We believe that this low-temperature thermal annealing method would make GO interfaces more accessible, especially for the development of nano-interfacial modifications for biological applications, revealing its potential for biomedical applications.

Dual-benefit strategy for developing an efficient photodetector with prompt response to UV-near IR radiations: in situ synthesis and crystallization through a simple one-step annealing

We fabricated an efficient C8-DPP-BP/G photodetector with prompt response to UV-near IR radiation through a dual-benefit strategy, in situ synthesis and crystallization using a simple one-step annealing technique.

All-in-one fabrication of a ratiometric electrochemical aptasensor with tetrahedral DNA nanostructure for fumonisin B1 detection.

Here, we develop an all-in-one strategy for efficient assembly of an electrochemical aptasensor. A multifunctional structure based on a tetrahedral DNA nanostructure (TDN) was synthesized via a one-step annealing process, providing DNA fixation, target recognition, signal amplification and space regulation. Based on the integration of this multifunctional structure, the sensing interface was assembled in one step. A ratiometric aptasensor was constructed by anchoring methylene blue (MB) to the TDN and ferrocene (Fc) on the cDNA. Using the ratio of the currents obtained from Fc and MB as a measure, the developed aptasensor shows excellent analytical performance for fumonisin B1 detection. This strategy is universal and could simplify the fabrication of aptasensors.

Reducing oil absorption in pea starch through two-step annealing with varying temperatures

In this study, we investigated the effects of one-step and two-step annealing on pea starch (PS) and their impact on the starch structure and oil absorption following frying. Compared to native PS, both one-step and two-step annealing treatments significantly reduced starch solubility, swelling power, oil absorption, and specific surface area while increasing water absorption. The extent of these changes depended on the specific annealing parameters applied. Notably, among all the starch samples, PS-45-55-F (PS subject to two-step annealing at 45 °C and then 55 °C, followed by frying) exhibited the lowest oil absorption. Scanning electron microscopy (SEM) results revealed that PS-45-F (PS subject to one-step annealing at 45 °C, followed by frying) and PS-45-55-F retained more of the original starch structure after frying. Analytical techniques including X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), and differential scanning calorimetry (DSC) consistently indicate that two-step annealed starch (PS-45-55-F) better preserved both long-range and short-range ordered structure of starch granules during frying. Additionally, it enhanced the thermostability of annealed starch, making it more effective in inhibiting oil absorption. These findings highlight the potential of two-step annealed starch for the development of low-oil, high-quality, and healthy fried or pre-fried food products, such as coated fried chicken and tempura.

Enhancing tensile properties by dual-precipitates in a CrFeNiVAl complex-concentrated alloy

Complex-concentrated alloys (CCAs) have gained significant attention in recent years due to their exceptional combination of high strength and ductility. In this work, a novel Cr18.5Fe21Ni46.3V4.2Al10 (at. %) CCA was designed and prepared. The dual-precipitates microstructures with hard B2 precipitates and coherent L12 nanoprecipitates, which provide a synergic strength-ductility effect, were introduced into a Cr18.5Fe21Ni46.3V4.2Al10 CCA through appropriate thermomechanical processing strategy. By severe cold rolling and one-step annealing of 1 h at 900 °C, the CCA exhibits a yield strength of 920 MPa, a tensile strength of 1230 MPa, and a uniform elongation of 23.8 %. Microstructure analysis revealed that the excellent mechanical properties are primarily due to coherent L12 nanoprecipitates being sheared by abundant stacking faults, which facilitates dislocation gliding and enhances the strain-hardening capability and ductility. However, the hard B2 precipitates have two different deformation mechanisms. On the one hand, the B2 precipitates are bypassed by dislocations, leading to the dislocation pile-ups against the interface between the B2 precipitates and the FCC matrix, which increases the strain hardening capability but induces stress concentrations. On the other hand, the B2 precipitates provide fine grain strengthening by hindering grain growth. Additionally, dual-precipitation phases also interact significantly with other crystal defects, such as dislocations, stacking faults, and nano twins. Our results demonstrate that the dual-precipitates microstructure is an effective strategy to achieve CCAs or other alloys with high strength-ductility balance.

Flaky N-doped hard carbon anode material for sodium-ion batteries

Hard carbon (HC), as a promising anode material for sodium ion batteries, its sluggish diffusion performance hinders further improvement of electrochemical performance. In the preparation process of HC materials, the screening and treatment of precursors can optimize the structure and morphology of HC products, further affecting electrochemical performance. Here, we use peptone as the precursor of HC and prepare flaky N-doped HC (PFNC) through a one-step annealing method. Benefitting from this structure, the prepared PNFC delivers a specific capacity of 315.5 mAh g−1 at a current density of 20 mA g−1 with excellent rate performance and cyclic stability. This work proves that peptone is a valuable carbon precursor, opening a new avenue for further application and development of HC.

Enhancing overall performances of Cu/Ag/AZO multilayer films for transparent heaters via laser/furnace step-by-step annealing mode

Four different step-by-step annealing modes based on furnace and/or laser annealing (i.e. F + L, F + F, L + F and L + L) were developed and compared with one-step furnace or laser annealing mode (i.e. F and L), with an aim to enhance overall performances of Cu/Ag/AZO (CAA) multilayer films applied to transparent heaters. It was found that the L + F step-by-step annealing mode improved the transmittance and conductivity of the CAA film to the greatest extent, and therefore the resulting sample L + F achieved the best overall performance with a figure of merit of 4.26 × 10−2 Ω−1. These results should be ascribed to that laser annealing for the AZO layer in the first step facilitated growth and recrystallization of AZO grains to provide better nucleation sites for overlying Ag and Cu grains, and furnace annealing of the whole CAA film in the second step promoted the melting of the surface Ag and Cu grains to re-aggregate with the nearby AZO grains. The transparent heater prepared from the sample L + F exhibited a high steady-state temperature of 127.1 °C within a short response time of 80 s under an input voltage of 3 V, as well as good heating stability and effective deicing function.

Towards High-Temperature MEMS: Two-Step Annealing Suppressed Recrystallization in Thin Multilayer Pt-Rh/Zr Films.

Platinum-based thin films are widely used to create microelectronic devices operating at temperatures above 500 °C. One of the most effective ways to increase the high-temperature stability of platinum-based films involves incorporating refractory metal oxides (e.g., ZrO2, HfO2). In such structures, refractory oxide is located along the metal grain boundaries and hinders the mobility of Pt atoms. However, the effect of annealing conditions on the morphology and functional properties of such multiphase systems is rarely studied. Here, we show that the two-step annealing of 250-nm-thick Pt-Rh/Zr multilayer films instead of the widely used isothermal annealing leads to a more uniform film morphology without voids and hillocks. The composition and morphology of as-deposited and annealed films were investigated using X-ray diffraction and scanning electron microscopy, combined with energy-dispersive X-ray spectroscopy. At the first annealing step at 450 °C, zirconium oxidation was observed. The second high-temperature annealing at 800-1000 °C resulted in the recrystallization of the Pt-Rh alloy. In comparison to the one-step annealing of Pt-Rh and Pt-Rh/Zr films, after two-step annealing, the metal phase in the Pt-Rh/Zr films has a smaller grain size and a less pronounced texture in the <111> direction, manifesting enhanced high-temperature stability. After two-step annealing at 450/900 °C, the Pt-Rh/Zr thin film possessed a grain size of 60 ± 27 nm and a resistivity of 17 × 10-6 Ω·m. The proposed annealing protocol can be used to create thin-film MEMS devices for operation at elevated temperatures, e.g., microheater-based gas sensors.

Study of the Structural, Electrical, and Mechanical Properties and Morphological Features of Y-Doped CeO2 Ceramics with Porous Structure

In this work, ceramic samples of cerium oxide doped with yttrium were investigated. The concentration of a dopant Y(NO3)3 varied from 5 to 25 wt% in the initial charge. In the course of the experiment, a simple method was developed to obtain ceramics with a porosity of ~20% via one-step annealing in air in a muffle furnace. For comparison, samples with two annealings were also synthesized to determine the effects of pores on electrical, structural, and mechanical characteristics. The obtained samples were examined via X-ray powder diffraction, scanning electron microscopy, X-ray energy dispersive spectroscopy, Raman spectroscopy, dielectric spectroscopy, and Vickers microhardness measurements. The substitution of Ce4+ ions with Y3+ ions led to a significant decrease in the lattice parameter, average crystallite size, and average grain size, with a simultaneous increase in the lattice defectivity, dielectric constant, electrical conductivity, and microhardness values. It is shown that samples with a dopant weight fraction of 0.05–0.15 and one-step annealing have favorable electrical and mechanical characteristics for energy applications as porous materials with ionic conductivity.