Growth Steps Research Articles

Optimized spacing of active sites in Ni-Mo catalysts enhances ethanol production in syngas conversion

The direct conversion of syngas to ethanol is highly attractive but remains challenging due to low CO conversion and poor EtOH/ROH. We investigated the conversion of syngas over a KNiMo2C catalyst modified with carbon dots (CDs) derived from Ligustrum lucidum leaves. On the Ni0.54Mo-A catalyst, a CO conversion of 43.4 % was achieved, with oxygenates selectivity and EtOH/ROH，reaching 48.2 % and 63.7 %, the space-time yield of ethanol was 132.5 mg/gcat/h. Comprehensive characterization revealed that CDs regulate the distance between Ni-Mo active sites, preventing excessive proximity and maintaining an optimal separation. This adjustment significantly enhances EtOH/ROH by modulating the probability of carbon chain growth. A potential new reaction pathway for directly converting syngas to ethanol is proposed, The C-C coupling of CHx* with *COOH or *CO2 is identified as a key step in carbon chain growth. This work provides a new catalytic pathway for the syngas to ethanol industry.

Incorporation of TC4 (Ti-6Al-4V) to construct strong interfacial bonding with Mg matrix to achieve improved hydrogen storage kinetics

Effective contact between the catalyst and the Mg/MgH2 matrix is the key to efficiently enhancing the hydrogen storage kinetics. In this work, a Mg-10 wt% TC4 (Ti-6Al-4V) composite with strong interfacial bonding was prepared by vacuum hot pressing sintering, and the reinforcement mechanism of TC4 was investigated. The results indicated that TC4 has a significant improvement effect on the activation efficiency and hydrogen absorption/desorption kinetics. The hydrogen absorption and desorption activation energies of AZ91-TC4 (53.0/111.3 kJ/mol) are 19.6 and 37.2 kJ/mol lower than that of AZ91 without TC4, respectively. Moreover, TC4 can cause AZ91 to start dehydrogenation at 449 K, and the reduction is about 110 K. Except for the increase of grain boundaries and microcracks caused by TC4, the transition diffusion interface formed by TC4 and Mg matrix with a lower diffusion barrier can be used as a special fast diffusion channel to accelerate the hydrogenation process controlled by H atom diffusion. Meanwhile, the kinetic calculations indicate that the dehydrogenation process of AZ91 is controlled by the nucleation and growth step of Mg, and its nucleation activation energy is ca. 4 times the growth activation energy. TC4 and its induced precipitation of TiAl and Al8Mn5 can dramatically accelerate the nucleation process of Mg, resulting in the rate-determining step changing to the surface penetration of H atoms, and the desorption rate is significantly improved. These positive findings provide new tactics for designing excellent hydrogen storage catalysts.

5131 Vanishing Act: Uncommon Case Of Pheochromocytoma With Positive Biochemical Work-up With Absence Of Tumor And Medullary Tissue

Abstract Disclosure: N. Chan: None. R. Kaufman: None. N. Farhat: None. G.Y. Kim: None. Pheochromocytomas are rare neuroendocrine tumors derived from adrenal chromaffin cells that result in hyperactivity of the sympathetic nervous system. In the United States, they occur in about 0.05% to 0.1% patients with sustained hypertension. We are presenting a case of a patient with biochemical evidence of pheochromocytoma, but surgical pathology revealed absence of tumor and residual normal medulla.80-year-old female with a history of follicular lymphoma and hypertension presented for evaluation of an incidental right-sided adrenal nodule noted on a PET-CT. She had a history of hypertension managed on lisinopril 40 mg, amlodipine 10 mg and atenolol 100 mg daily. She denied a history of weakness, dizziness, headaches, palpitations, or easy bruising. Workup was negative for primary aldosteronism and Cushing’s Syndrome. Plasma normetanephrines was high at 675.7 pg/mL (0-285.2 pg/mL). 24-hour urinary normetanephrine was also elevated at 562 ug/g (0-400 ug/g). CT abdomen and pelvis with and without contrast revealed a 1.4 cm right adrenal nodule approximately 16 Hounsfield units. These findings were suggestive of pheochromocytoma. She was pre-treated with alpha blockade and subsequently had a robotically assisted laparoscopic right adrenalectomy. Postoperatively, the patient was hypotensive and required vasopressors. She was eventually weaned off vasopressors and discharged on lisinopril 20 mg daily. Soon after discharge, the patient was complaining of hypotension and this dose was halved. 4 weeks postoperatively, laboratory evaluation showed normalization of plasma normetanephrines to 0.83 nmol/L (0-0.89 nmol/L). Surgical pathology revealed an infarcted benign adrenal cortical proliferative lesion with background of cortical hyperplasia, fibrotic adrenal medullary region, and hemosiderin deposition. There was no identifiable medullary neoplasm and no residual medulla.Pheochromocytomas are highly vascular tumors as angiogenesis is a critical step in tumor growth, which can lead to frequent infarcts. This case shows classic biochemical evidence of pheochromocytoma. Interestingly, the resulting clinical examination displayed obliteration of the medullary tissue. Complete disappearance of both tumor and residual normal medulla is extraordinarily rare. The pre-operative hormonal levels in association with findings of complete absence of neoplastic and nonneoplastic medullary tissue cannot be explained. Presentation: 6/1/2024

CD44: A Stemness Driver, Regulator and Marker - all in one?

Although the concept of cancer stem cells is still controversial, previous studies have shown that blood cancers, as well as specific types of solid cancers such as colorectal cancer, rely on stem cells during the onset of tumor growth and further tumor development. Moreover, resistance to therapeutic treatment in leukemias such as acute myeloid leukemia and in colorectal cancer can be attributed to a small population of cells with stemness properties known as minimal residual disease. In this review, we look back on the discovery of cancer stem cells and the contribution of the findings in blood cancer to a parallel discovery in solid cancers. We focus on CD44 as a stem cell marker, both in blood cancers and in several types of solid cancers, particularly of the gastro-intestinal tract. This review highlights newly discovered molecular mechanisms of action of CD44 which indicate that CD44 has indeed a function in stemness, stem cell maintenance and drug resistance. We attempt here to make the link between the functions of CD44 isoforms in stemness and their involvement in specific steps of tumor growth and metastasis.

Exploring the mechanisms of benzanilide crystal growth and morphology: Crystal surface structure, solvent diffusion and solvent-interface interactions

Flaky crystals are fragile, rendering them unsuitable for various applications including use, processing, storage and transportation. This work investigates the growth and morphology regulation mechanisms of flaky crystals using benzanilide as a model material. Initially, block-like crystals are prepared by solvent screening and cooling crystallization with its morphology greatly improved. Subsequently, growth kinetics of (111), (1–10) and (020) faces are established with crystal growth experiments. The crystal growth of (001) face is also determined to follow a two-dimensional nucleation model with the microscopic surface analysis using atomic force microscopy. The changes of the surface integration resistance and the growth step height are regarded as kinetic mechanisms of the growth behavior and crystal morphology modulation by solvent and supersaturation. Finally, the molecular mechanism of the modulation of the solvent in crystal morphology is revealed base on crystal surface structure analysis and molecular dynamics simulations. The weak solvent-interface polar interactions facilitate the incorporation of benzanilide molecules into the weak polarity (001) face, leading to the surface roughening and increased crystal thickness when employing strongly polar solvents such as acetonitrile. Unlike the former, the relatively weak hydrogen bonding interactions between solvents and strong polarity (020) face, and the higher diffusion ability of molecules promote the rapid growth and disappearance of (020) face in ethanol and acetonitrile with strong hydrogen bond formation ability. This study can contribute to a deeper understanding of the solvent effect on crystal morphology and provide guidance for optimizing crystallization conditions to obtain shape-tailored crystal products.

Role of silicon in the growth of ZSM-5 synthesized with coal fly ash as raw materials

In this work, single-phase ZSM-5 zeolite was synthesized using solid waste coal fly ash (CFA) as raw material, providing a potential alternative for creating high-value-added products from this waste. X-ray diffraction (XRD), scanning electron microscopy, X-ray fluorescence, Fourier transform infrared spectroscopy, N2 physisorption, and other techniques were used to evaluate the crystallization and morphology of the ZSM-5 obtained. The results indicated that ZSM-5 can be synthesized by the simple method of mixing, stirring, and heating. A well-defined hexagonal shape of ZSM-5 with a specific surface area of 162 m2/g and mesoporous structure was obtained at the temperature of 160 °C during hydrothermal treatment for 72 h. Theoretically, the mechanism of crystal growth of ZSM-5, i.e. the liquid phase nucleation and step growth models, was clarified. These results open the possibility of exploring the crystallization of ZSM-5 and the utilization of CFA. Simultaneously, the critical roles of silicon in framework formation and crystallization control during the formation and growth of zeolites were elucidated.

An adaptive fatigue crack growth model at the welded joints of steel bridge

Under the influence of random loads such as those from vehicles, the welded details in steel bridges tend to gradually develop into macrocracks, typically originating from manufacturing defects or stress concentration points. As the service life of the steel bridge increases, the continuous generation and propagation of fatigue cracks lead to a decline in the bridge's service performance, potentially resulting in catastrophic failures such as bridge collapse. Accurately analyzing the fatigue crack growth patterns at welded joints is a prerequisite for reliably assessing the structural service performance. The analysis of fatigue crack propagation depends on both the crack growth step size and the cyclic stress–strain response at the welded joint under loading. Considering the complexity of the material properties and stress concentration at the welded joint, which leads to a lack of analytical solutions for the cyclic stress–strain characteristics at the crack tip, numerical analysis was employed to obtain the cyclic stress–strain response at the crack tip of the welded joints. Using the size of the cyclic plastic zone at the crack tip as an adaptive crack growth step size, a model for fatigue crack growth was developed based on the plastic strain energy of the cyclic plastic zone. Fatigue test specimens extracted from the welded toe of cruciform welded joints were tested, providing cyclic stress–strain (Ramberg-Osgood material parameters) and fatigue damage characteristics (Manson-Coffin material parameters) of the material at the welded toe. High-cycle fatigue tests using cruciform welded joint specimens determined a good correlation between the crack propagation characteristic dimensions obtained from the adaptive numerical analysis model and the experimental results. The experimental findings confirmed the applicability of the established adaptive numerical analysis model for studying fatigue crack growth in cruciform welded joints. The parameters introduced in this model are physically meaningful, easy to obtain, and suitable for engineering applications.

High-Quality SiC Crystal Growth by Temperature Gradient Control at Initial Growth Stage

A modified process condition has been proposed for the growth of high-quality 6-inch 4H-SiC single crystal. Temperature gradient (dT[°C] = Tbottom-Tupper) was controlled by changing coil position in order to investigate the effect of the temperature gradient on the SiC crystal quality. SiC ingot surface and etch pit density (EPD) of etched SiC wafer were investigated according to different dT conditions at the initial stage of SiC crystal growth. The surface of SiC crystal ingots grown with different dT for 10h were observed by OM and etched SiC wafers were prepared from SiC crystal ingots after main growth step for 100h. Different dT conditions in the initial growth stage resulted in dramatically different surface images and the crystal quality evaluated by EPD.

The Complement System Is Essential for Arteriogenesis by Enhancing Sterile Inflammation as a Relevant Step in Collateral Artery Growth.

Arteriogenesis is an inflammatory driven mechanism, describing the growth of a natural bypass from pre-existing collateral arteries to compensate for an occluded artery. The complement system component C3 is a potent natural inflammatory activator. Here, we investigated its impact on the process of collateral artery growth using C3-deficient (C3 -/-) and wildtype control mice in a murine hindlimb model of arteriogenesis. Induction of arteriogenesis by unilateral femoral artery ligation resulted in decreased perfusion recovery in C3 -/- mice on day 7 as shown by Laser Doppler imaging. Immunofluorescence staining revealed a reduced vascular cell proliferation in C3 -/- mice. Gene expression analysis displayed a significant reduction in monocyte chemoattractant protein-1 (MCP-1) expression in C3 -/- mice. Interestingly, 3 days after induction of arteriogenesis, the number of macrophages (CD68+) recruited to growing collaterals was not affected by C3 deficiency. However, a significant reduction in inflammatory M1-like polarized macrophages (CD68+/MRC1-) was noted. Forced mast cell activation by Compound 48/80 as well as exogenous MCP-1 application rescued the number of M1-like polarized macrophages along with perfusion recovery in C3 -/- mice. In summary, this study demonstrates that complement C3 influences arteriogenesis by mediating MCP-1 expression, which is essential for the induction and enhancement of sterile inflammation.

Monitoring the dynamics of nanozeolite formation by combined in situ coherent small angle X-ray scattering techniques

Understanding the dynamics of zeolite formation is key to synthesising high-quality zeolitic materials with controllable properties, in order to develop more efficient and performant materials. X-ray photon correlation spectroscopy (XPCS) using coherent X-rays offers new possibilities for in situ observation of nano to micron-scale fluctuation dynamics during crystal growth. An in situ cell, which is capable of collecting time-resolved coherent X-ray scattering data under hydrothermal conditions has been developed and used to study, by in situ XPCS combined with small and wide angle X-ray scattering, zeolite formation and dynamics. Analysis of the results using two-time correlations enables to accurately identify the successive growth and crystallisation steps, revealing the dissolution process of the LTA topology during the SOD growth. This approach opens a powerful new avenue for studying the dynamics of nanomaterials formation, phase transitions and growth processes under in situ conditions that will enable profound insights into the nanoscale synthesis mechanisms.

Re-designing nano-silver technology exploiting one-pot hydroxyethyl cellulose-driven green synthesis.

Re-designing existing nano-silver technologies to optimize efficacy and sustainability has a tangible impact on preventing infections and limiting the spread of pathogenic microorganisms. Advancements in manufacturing processes could lead to more cost-effective and scalable production methods, making nano-silver-based antimicrobial products more accessible in various applications, such as medical devices, textiles, and water purification systems. In this paper, we present a new, versatile, and eco-friendly one-pot process for preparing silver nanoparticles (AgNPs) at room temperature by using a quaternary ammonium salt of hydroxyethyl cellulose (HEC), a green ingredient, acting as a capping and reducing agent. The resulting nano-hybrid phase, AgHEC, consists of AgNPs embedded into a hydrogel matrix with a tunable viscosity depending on the conversion grade, from ions to nanoparticles, and on the pH. To investigate the synthesis kinetics, we monitored the reaction progress within the first 24h by analyzing the obtained NPs in terms of particle size (dynamic light scattering (DLS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM)), Z-potential (ELS), surface plasmon resonance (UV-VIS), crystallographic phase (XRD), viscosity, and reaction yield (inductively coupled plasma-optical emission spectrometry (ICP-OES)). To explore the design space associated with AgHEC synthesis, we prepared a set of sample variants by changing two independent key parameters that affect nucleation and growth steps, thereby impacting the physicochemical properties and the investigated antimicrobial activity. One of the identified design alternatives pointed out an improved antimicrobial activity in the suspension, which was confirmed after application as a coating on nonwoven cellulose fabrics. This enhancement was attributed to a lower particle size distribution and a positive synergistic effect with the HEC matrix.

Synthesis of Ag Doped ZnO Nanowire by Hydrothermal Method and its Characterization

This research is mainly focused over synthesizing zinc oxide (ZnO) nanowire (NW) and silver doped zinc oxide nanowires (Ag/ZnO) using two step hydrothermal method which comprises of seed layer deposition and hydrothermal nanowire growth step. Hydrothermally grown nanowires are of great significance. The synthesized nanowires were characterized by UV-Vis Spectroscopy (UV-Vis), X- ray Diffraction Spectroscopy (XRD), Energy Dispersive Spectroscopy (EDS), Field Emission Scanning Electron Microscopy (FE-SEM) and High-Resolution Transmission Electron Spectroscopy (HR-TEM). XRD pattern revealed as-synthesized materials are of crystalline nature having crystallite size of 166.27 nm and 42.32 nm for ZnO nanowire and Ag doped nanowire, respectively. Further confirmation was done by EDS, SEM and TEM. The microscopic images of SEM and TEM evidenced for successful fabrication of nanowires.

Protein inclusion into ice can dissociate subunits

An antifreeze protein's inclusion into ice can be used to purify it from other proteins and solutes. Domains that are covalently attached to the antifreeze protein are also drawn into the ice such that the ice-binding portion of the fusion protein can be used as an affinity tag. Here we have explored the use of ice-affinity tags on multi-subunit proteins. When an ice-binding protein was attached as a tag to multisubunit complexes a substantial portion of each multimer dissociated during overgrowth by the ice. The protein subunit attached to the affinity tag was enriched in the ice and the other subunit was appreciably excluded. We suggest that step growth of the advancing ice front generates shearing forces on the bound complex that can disrupt non-covalent protein-protein interactions. This will effectively limit the use of ice-affinity tags to single subunit proteins.

Early Stages of FUS Droplet Formation via Liquid-Liquid Phase Separation.

The phase behavior of complex biomolecular solutions may explain different cellular processes, including the organization of cells by membraneless organelles. The early stages of phase separation are crucial to understanding the underlying mechanism and identifying biomolecules that trigger or drive the transition. Here, we analyze the early events of liquid-liquid phase separation (LLPS) of FUS by multiangle time-resolved static and dynamic light scattering. LLPS was triggered by TEV-catalyzed cleavage of the MBP-tag from FUS-MBP. The light scattering measurements revealed the existence of at least two fractions of FUS-MBP aggregates already prior to the onset of LLPS. The orders of magnitude of the aggregate size in these two fractions are 10 and 100 nm, respectively. LLPS started after an induction period, which depended on the concentration of FUS-MBP. The data from time-dependent light scattering revealed a coalescence of droplets also denoted as a step growth process. A step growth process instead of nucleation and growth via monomer addition suggests that LLPS takes place within the spinodal rather than between the binodal and the spinodal.

Data-driven constitutive meta-modeling of nonlinear rheology via multifidelity neural networks

Predicting the response of complex fluids to different flow conditions has been the focal point of rheology and is generally done via constitutive relations. There are, nonetheless, scenarios in which not much is known from the material mathematically, while data collection from samples is elusive, resource-intensive, or both. In such cases, meta-modeling of observables using a parametric surrogate model called multi-fidelity neural networks (MFNNs) may obviate the constitutive equation development step by leveraging only a handful of high-fidelity (Hi-Fi) data collected from experiments (or high-resolution simulations) and an abundance of low-fidelity (Lo-Fi) data generated synthetically to compensate for Hi-Fi data scarcity. To this end, MFNNs are employed to meta-model the material responses of a thermo-viscoelastic (TVE) fluid, consumer product Johnson’s® Baby Shampoo, under four flow protocols: steady shear, step growth, oscillatory, and small/large amplitude oscillatory shear (S/LAOS). In addition, the time–temperature superposition (TTS) of the material response and MFNN predictions are explored. By applying simple linear regression (without induction of any constitutive equation) on log-spaced Hi-Fi data, a series of Lo-Fi data were generated and found sufficient to obtain accurate material response recovery in terms of either interpolation or extrapolation for all flow protocols except for S/LAOS. This insufficiency is resolved by informing the MFNN platform with a linear constitutive model (Maxwell viscoelastic) resulting in simultaneous interpolation and extrapolation capabilities in S/LAOS material response recovery. The roles of data volume, flow type, and deformation range are discussed in detail, providing a practical pathway to multifidelity meta-modeling of different complex fluids.

Self-powered broadband photodetectors based on Bi2O2Se with asymmetric contact areas

Self-powered broadband photodetectors are widely used in military reconnaissance, outdoor environmental sensing, wearable medical monitoring. Current commercial broadband photodetectors based on conventional materials are structurally complex, high cost, and external power consumption. 2D materials emerge as promising candidates for the development of novel photodetectors with superior performances. The construction of self-powered photodetectors predominantly employs the heterostructures or metal–semiconductor–metal (MSM) configurations, which still suffer from either multiple steps of material growth, transferring, alignment or various photolithography, film deposition techniques. Herein, a simple and effective asymmetric contact strategy is proposed to fabricate Bi2O2Se-based self-powered broadband photodetectors with asymmetric Au contact areas. The photodetector exhibits excellent performance under 350–1150 nm illumination. The responsivity is as high as 1.38, 4.76, and 0.63 A/W under 350, 550, and 1050 nm, respectively, which are much higher than those of the previously reported self-powered photodetectors based on Bi2O2Se nanosheets. Meanwhile, the self-powered photodetector has a high external quantum efficiency of 1073.16 % at 550 nm. In addition, the photodetector has excellent stability in the air and enables both imaging and optical communication. Owing to the simple architecture, cost-effectiveness, straightforward manufacturing process, and impressive performance, the proposed self-powered photodetectors hold considerable promise for future applications.

Lead-free methyl ammonium tin iodide perovskite thin film growth in single step via plasma enhanced chemical vapour deposition technique and its optoelectronic properties

In the present work, lead free methyl ammonium tin iodide (CH3NH3SnI3 or MASnI3) perovskite thin films have been deposited via single step plasma enhanced chemical vapour deposition (PECVD) technique. In our earlier work, we reported lead based methyl ammonium lead iodide (CH3NH3PbI3 or MAPbI3) perovskite thin film deposition in 2-step, using sputtering technique for the PbI2 thin films and PECVD technique for CH3NH3I (MAI) thin films. Similarly, CH3NH3SnI3 perovskite thin films are deposited in this work using PECVD technique in single step. Lead is substituted with tin due to its toxic behaviour, environmental and health related issues. CH3NH3SnI3 perovskite is doped n-type via changing the molar ratio of SnI2 and CH3NH3I. SnI2/CH3NH3I ratio is changed from 0.33 to 2 to study the n-type doping of CH3NH3SnI3 perovskite. Deposited CH3NH3SnI3 perovskite thin films are deposited over p-type silicon wafer to make n-type doped n-CH3NH3SnI3/p-Si heterojunction photodiode.

Impact of Particle Size on the Nonlinear Magnetic Response of Iron Oxide Nanoparticles during Frequency Mixing Magnetic Detection.

Magnetic nanoparticles (MNPs), particularly iron oxide nanoparticles (IONPs), play a pivotal role in biomedical applications ranging from magnetic resonance imaging (MRI) enhancement and cancer hyperthermia treatments to biosensing. This study focuses on the synthesis, characterization, and application of IONPs with two different size distributions for frequency mixing magnetic detection (FMMD), a technique that leverages the nonlinear magnetization properties of MNPs for sensitive biosensing. IONPs are synthesized through thermal decomposition and subsequent growth steps. Our findings highlight the critical influence of IONP size on the FMMD signal, demonstrating that larger particles contribute dominantly to the FMMD signal. This research advances our understanding of IONP behavior, underscoring the importance of size in their application in advanced diagnostic tools.

Improving luminescence response in ZnGeN2/GaN superlattices: defect reduction through composition control

Color-mixed (cm) light-emitting diodes (LEDs) are theoretically the most efficient white light emitters, projected to improve white light luminous efficacy by 34% compared to incumbent phosphor converted LEDs. Since white light technology is pervasive and essential, small improvements in LED technology can result in energy savings. However, cm-LEDs are not yet realized due to poor efficacy in green and amber emitting materials, a spectral region colloquially referred to as the Green Gap. ZnGeN2 is nearly isostructural and closely lattice-matched to GaN and can be heteroepitaxially integrated with existing GaN devices; ZnGeN2/GaN hybrid structures are theorized to emit green (~530 nn) light with a spontaneous emission rate 4.6–4.9 times higher than traditional InGaN LEDs when incorporated into III-N LED structures. In this report we demonstrate the molecular beam epitaxy (MBE) growth of GaN and ZnGeN2 superlattices, an important step towards realizing multiple quantum well structures required for efficient LEDs. Elemental analysis, including atom probe tomography, shows that Ga and Ge are observed in both ZnGeN2 and GaN layers, degrading the structural uniformity. The lack of elemental abruptness also leads to increased defect luminescence and reabsorption of band edge luminescence. The source of unintentional Ga distributed throughout the ZnGeN2 layers was identified as excess flux escaping from around the closed MBE shutter. The source of unintentional Ge, which tended to incorporate as a single delta-doped layer in GaN, was identified as Ge riding along the cyclical metal-rich Ga adlayer used for high quality GaN, incorporating during subsequent nitrogen-rich growth step. Modifying the growth strategy results in improved structural quality, elemental abruptness, and luminescence response. This realization of structurally and elementally abrupt interfaces demonstrates the potential of heteroepitaxially integrated binary and ternary nitrides for energy-relevant devices.

Effect of cooling rate on the precipitation characteristics and growth mechanism of Bi3Ni in liquid lead‑bismuth eutectic

Austenitic stainless steel is a promising candidate structural material for direct contact components with lead‑bismuth eutectic (LBE) in lead-cooled fast reactor (LFR). However, the preferential dissolution of Ni from austenitic steels at low oxygen concentrations will lead to the precipitation of Ni-containing phases in the low-temperature parts of reactors, which has a risk of pipe clogging. In this paper, three samples, comprising one extracted from a corrosion tank after prolonged operation and two prepared, respectively, by quenching in liquid nitrogen and cooling in the furnace, were obtained to investigate the effect of cooling rate on the precipitation characteristics and growth mechanism of Bi3Ni that forms by the reaction of dissolved Ni and Bi in LBE. The results showed that rod-like Bi3Ni was found in all three Ni-containing LBE samples. As the cooling rate increased, the width of Bi3Ni decreased. The Bi3Ni in all three samples displayed a pseudo-hexagonal prismatic shape and had a typical faceted growth character; the cooling rate had no effect on the morphology of them. The crystallographic analysis showed that the growth axis of Bi3Ni was in the 〈010〉 direction, and the prism planes were composed of {001} and {101}. In addition, the precipitation of Bi3Ni inevitably increased the content of Pb7Bi3, which would in turn enhance the volumetric expansion of solid LBE samples. For the growth mechanism, Bi3Ni phases were controlled by the screw dislocation mechanism, with the step growth rate of the dislocation core being greater than that of the outer edges. Given the low cooling rate and low Ni content in the LBE coolant of reactors, the precipitation of Bi3Ni with a rod-like morphology seems to be inevitable.