Growth Method Research Articles

Gold Nanoprobes for Detection of a Crucial EGFR Deletion for Early Diagnosis of Non-Small-Cell Lung Cancer

Gold nanoparticles (AuNPs) exhibit improved optical and spectral properties compared to bulk materials, making them suitable for the detection of DNA, RNA, antigens, and antibodies. Here, we describe a simple, selective, and rapid non-cross linking detection assay, using approx. 35 nm spherical Au nanoprobes, for a common mutation occurring in exon 19 of the epidermal growth factor receptor (EGFR), associated with non-small-cell lung cancer cells. AuNPs were synthesized based on the seed-mediated growth method and functionalized with a specific 16 bp thiolated oligonucleotide using a pH-assisted method. Both AuNPs and Au nanoprobes proved to be highly stable and monodisperse through ultraviolet-visible spectrophotometry, dynamic light scattering (DLS), and electrophoretic light scattering (ELS). Our results indicate a detection limit of 1.5 µg mL−1 using a 0.15 nmol dm−3 Au nanoprobe concentration. In conclusion, this work presents an effective possibility for a straightforward, fast, and inexpensive alternative for the detection of DNA sequences related to lung cancer, leading to a potential platform for early diagnosis of lung cancer patients.

Layer-by-layer growth of Cu3(HHTP)2 films on Cu(OH)2 nanowire arrays for high performance ascorbic acid sensing

Growing three-dimensional (3D) metal organic frameworks (MOFs) via heterogeneous epitaxial growth on metal hydroxide arrays are effective for constructing electrochemical sensor. However, the growth of MOFs is difficult to control, resulting in thick and irregular morphologies and even damage the metal hydroxide template. In this work, Cu3(HHTP)2 (HHTP = 2, 3, 6, 7, 10, 11-hexahydroxytriphenylene) films with controllable thickness and morphology were successfully prepared on Cu(OH)2 nanowire arrays (NWAs) through layer-by-layer (LBL) growth method. We have discovered that the LBL cycle and the reaction solvent composition are crucial for growing homogenous MOF thin films. The Cu3(HHTP)2 based ascorbic acid (AA) sensor, fabricated in ethanol within 10 LBL cycles, generated an ultrahigh sensitivity of 821.64 μA mM−1 cm−2 in the range of 6–981.41 μM, a low detection limit of 60 nM as well as the great selectivity, stability and reproducibility. Moreover, the relative deviation for AA detection in two fruit juices were 3.22 % and 3.71 %, and the test result for human sweat fall within the normal AA concentration range, verifying the feasibility of as-prepared sensor for practical application.

Zeolite A Thin Film Growth on Silica Optical Fibers

Thin films of zeolite A (Linde type A, LTA) were fabricated on silica optical fibers using dip coating method, followed by a secondary growth process. Zeolite A seed crystals with an average crystal size of 247.3 nm were synthesized through hydrothermal method. Then, the dip coating technique was applied to coat silica optical fibers. The one and two-time dip coating resulted in island-like growth, while three-time dip coating process led to the intergrowth of seed crystals, resulting in nearly continuous films on the optical fiber. The seed crystals, initially deposited as a monolayer, were grown by secondary growth method, leading to film thicknesses of 255.3 nm ± 10.1 nm (average ± standard deviation). Upon extending the secondary growth reaction time from 2 hours to 4 hours, the film thickness increased from 255.3 nm ± 10.1 nm to 649.6 nm ± 28.1 nm. Epitaxial growth was identified as the mechanism through which the seed crystals grow. The nanoporous zeolite A films formed on the optical fiber exhibit potential applications as gas sensors. These sensors function by detecting changes in optical reflection caused by the differential adsorption of gases.

Defects Detection of Lithium-Ion Battery Electrode Coatings Based on Background Reconstruction and Improved Canny Algorithm

Aiming to address the problems of uneven brightness and small defects of low contrast on the surface of lithium-ion battery electrode (LIBE) coatings, this study proposes a defect detection method that combines background reconstruction with an enhanced Canny algorithm. Firstly, we acquire and pre-process the electrode coating image, considering the characteristics of the electrode coating process and defects. Secondly, background reconstruction and the difference method are introduced to achieve the rough localization of coating defects. Furthermore, the image with potential defects undergoes enhancement through improved Gamma correction, and the PSO-OTSU algorithm with adaptive searching is applied to determine the optimal segmentation. Finally, precise defect detection is accomplished using the improved Canny algorithm and morphological processing. The experimental results show that, compared with the maximum entropy method, the region growth method, and the traditional Canny algorithm, the algorithm in this paper has a higher segmentation accuracy for defects. It better retains defect edge features and provides a more accurate detection effect for defects like scratches, dark spots, bright spots, metal leakage, and decarburization, which are difficult to recognize on the background of coating areas of electrodes. The proposed method is suitable for the online real-time defect detection of LIBE coating defects in actual lithium-ion battery industrial production.

Hydrothermal synthesis of highly cross‐linked PtZn@Silicalite‐1 structured catalysts for propane dehydrogenation

AbstractStructured catalysts coatings exhibit excellent performance on non‐adiabatic gas–solid process, deriving from their enhanced heat and mass transfer properties. However, the coating catalysts prepared by traditional hydrothermal method of zeolite encapsulating noble metal are prone to spalling, especially under conditions of large flow rate and high temperature. Herein, we prepared PtZn clusters encapsulated in silicalite‐1 zeolite coating on stainless steel with high bonding strength by an improved in situ growth method. The optimized catalyst exhibited ultra‐thin, uniform, continuous, and high degree of crosslinking, thereby enhancing mass transfer and thermal stability. In propane dehydrogenation reaction, the optimized PtZn@S‐1‐R showed a high specific activity of 14.7 molPt−1 s−1 and a propylene selectivity above 99% at 600°C with a high weight hourly space velocity of 120 h−1. The metal‐encapsulated zeolite coating catalysts broaden the application avenue for heterogeneous catalysis with great application prospects.

Preparation and application of soil conditioner using iron ore tailings-biochar composite material

Iron ore tailings (IOT) are industrial solid wastes that pose environmental threats. This study prepared IOT-biochar composite materials as multifunctional soil conditioners through an in-situ growth method. Biochar served as a carrier to improve the dispersity and reactivity of IOT in soil. The IOT-biochar composite (FeOT-BC) showed balanced impacts on soil properties, increasing pH, organic matter and available nutrients compared to IOT alone. This was due to the buffering effects of biochar. In pot experiments, FeOT-BC significantly promoted rice plant growth compared to IOT alone. The improvements were attributed to the improved soil fertility and increased microbial activities induced by biochar. The results suggest that integrating IOT with biochar can mitigate the negative effects of tailings and convert them into a value-added product. The biochar component can optimize the performance of IOT by moderating soil acidification, enhancing nutrient release from iron minerals, and stimulating microbial activities. The IOT-biochar composite materials integrate the functionalities of both components for optimized soil conditioning effects, providing a promising strategy for comprehensive tailings utilization.

Novel application of high temperature solution growth method in simultaneously preparing SiC/Ti3SiC2/TiC using photovoltaic Si waste and Ti-bearing blast furnace slag

Photovoltaic silicon wastes (PVSWs) and Ti-bearing blast furnace slag (TBBFS) are typical new energy solid waste and traditional industrial solid waste respectively. The collaborative treatment of PVSW and TBBFS can realize the utilization of Si and Ti resources, as well as safeguard the ecosystems. Herein, an effective approach was proposed to prepare SiC, Ti3SiC2, and TiC using these two wastes as raw materials based on the innovative application of High Temperature Solution Growth Method (HTSGM). A Ti–Si alloy, which is rich in TiSi2 phase (stable) with a low melting point is synthesized from TBBFS through silicothermal reduction at a low operating temperature of HTSGM. Subsequently, the directional solidification process effectively optimized the segregation and carbon solubility of Ti–Si alloy, leading to the formation of TiC, Ti3SiC2, and SiC. The effect of directional solidification rate and the electromagnetic field is analyzed on in situ carburizing behavior and segregation of Ti–Si alloy, as well as controlled precipitation interval of the three carbides. Through the microcrystalline materialization treatment strategy of the associated waste slag, the entire process is devoid of solid waste or other pollution, achieving high-value and complete utilization of the two solid wastes. This work provides an innovative process for the green, clean, efficient, and high-quality collaborative treatment of PVSW and TBBFS.

Growth of Sb[formula omitted]Te[formula omitted] thin films on Ge(111) sample by thermal deposition: Morphological and electronic properties

Sb2Te3 is a well-known thermoelectric material and a topological insulator and its utilization is foreseen for many applications, such as quantum computing, mode-locking of laser systems, and cooling systems. Various methods have been used to grow thin Sb2Te3 films on different substrates, such as molecular beam epitaxy or electrodeposition. Often, such methods require performing laborious and rigid steps in order to optimize film growth and reduce the amount of defects. For this reason, we investigate a simplified growth method: thermal deposition starting from Sb2Te3 lumps followed by annealing. By means of various surface science techniques (LEED, STM, XPS), we show that it is possible to obtain a single crystalline Sb2Te3 film on a Ge(111) substrate. The film, which is amorphous after deposition, undergoes a phase transition and becomes crystalline after annealing at 573 K. This is clearly shown by a 1x1 surface termination typical of a (0001) surface with hexagonal lattices. The presence of several quintuple-layer steps was observed by scanning tunneling microscopy. Photoelectron spectroscopy characterization confirms that the grown chalcogenide film presents the expected stoichiometry (Te/Sb=1.5). The proposed method simplifies the growth phase and seems to reduce the number of defects induced by the growth technique, major advantages for many applications.

Synthesis of N-doped graphene film with tunable graphitic and pyridinic doping content

Nitrogen-doped (N-doped) graphene films with up to a 17.39 at.% doping level were synthesized with the chemical vapor deposition growth method. An extensive range of tunable nitrogen doping levels was achieved by selecting organic molecules as precursors grown at a wide temperature range of 300 to 1000 °C. The benzene rings in the precursor significantly reduced the energy requirements of N-doped graphene. The incorporation of bridgehead nitrogen and amino groups ensured a high nitrogen doping level and offered the tunable modulation of nitrogen dopant concentrations. The influence of temperature on the nitrogen content was investigated, distinguishing the graphitic and pyridinic dopant types, each demonstrating unique trends considering the dopant stability and growth mechanism. Specifically, the proportion of graphitic doping could be modulated from 40 % to 100 %. Notably, the pyrrolic type was absent at lower temperatures and was nearly negligible at elevated temperatures. Therefore, we developed a synthesis method for N-doped graphene growth that allowed for the selective and prioritized tuning of nitrogen dopant types. This method is particularly favorable when specific nitrogen dopants at certain doping levels are required for electrical and chemical catalytic applications.

Tuning the Geometry and Optical Chirality of Pentatwinned Au Nanoparticles with 5-Fold Rotational Symmetry.

Chirality transfer from chiral molecules to chiral nanomaterials represents an important topic for exploring the origin of chirality in many natural and artificial systems. Moreover, developing a promising class of chiral nanomaterials holds great significance for various applications, including sensing, photonics, catalysis, and biomedicine. Here we demonstrate the geometric control and tunable optical chirality of chiral pentatwinned Au nanoparticles with 5-fold rotational symmetry using the seed-mediated chiral growth method. A distinctive growth pathway and optical chirality are observed using pentatwinned decahedra as seeds, in comparison with the single-crystal Au seeds. By employing different peptides as chiral inducers, pentatwinned Au nanoparticles with two distinct geometric chirality (pentagonal nanostars and pentagonal prisms) are obtained. The intriguing formation and evolution of geometric chirality with the twinned structure are analyzed from a crystallographic perspective upon maneuvering the interplay of chiral molecules, surfactants, and reducing agents. Moreover, the interesting effects of the molecular structure of peptides on tuning the geometric chirality of pentatwinned Au nanoparticles are also explored. Finally, we theoretically and experimentally investigate the far-field and near-field optical properties of chiral pentatwinned Au nanoparticles through numerical simulations and single-particle chiroptical measurements. The ability to tune the geometric chirality in a controlled manner represents an important step toward the development of chiral nanomaterials with increasing architectural complexity for chiroptical applications.

Zone‐based failure risk assessment of fatigue crack growth caused by initial defects in powder turbine disc

AbstractIn this research, A zone‐based failure risk assessment (FRA) method of fatigue crack growth (FCG) caused by initial defects in the FGH96 alloy turbine disc is developed. Firstly, the initial defects distribution in the FGH96 alloy turbine disc is calculated based on the defect data. Subsequently, a probabilistic short FCG life model is established, taking into account the dispersion in grain size. Meanwhile, a probabilistic long FCG life model is established, incorporating the life dispersion factor. To calculate the Stress Intensity Factor (SIF) at any position of the disc, the general weight function method and the rectangular plate model are established. Finally, the zoning process is established, enabling a FRA that considers the FCG due to initial defects. The results indicate that the number of cycles corresponding to a 0.13% failure probability of the turbine disc is 7150, and the percentage of failures in each zone is analyzed.

Zero-dimensional organic-inorganic hybrid cuprous halide of (C20H20OP)CuCl2 with high anti-water stability

Recently, copper(I)-based metal halides have gained increasing attention due to their diverse structures and desirable optoelectronic properties. Herein, we report a novel zero-dimensional (0D) Cu-based halide (C20H20OP)CuCl2 [C20H20OP+ = (Methoxymethyl)triphenylphosphonium chloride cation], single crystals (SCs) of which were synthesized by a simple solution growth method. The bulk assembly of the periodic 0D structure is formed by the organic cation [C20H20OP]+ surrounding isolated [CuCl2]- units. The (C20H20OP)CuCl2 single crystals emit broadband yellow light upon UV excitation. Similarity to hybrid Br−/I− based copper compounds, as-synthesized compound displays remarkable resistance to water, maintaining its photoluminescence (PL) intensity at over 94% even after being immersed in water for 24 h. This work demonstrates the potential of constructing luminescent materials with high water resistance, which will pave the way for a new approach to developing water-resistant materials based on lead-free metal halides.

Facile construction of a novel S-scheme Fe2TiO5/BiVO4 photocatalyst for efficient visible light-driven fenton-like degradation of ciprofloxacin

The rational design and fabrication of stable and efficient heterogeneous Fenton-like catalyst is of great significance for wastewater treatment, but is still fraught with obstacles. In this paper, a novel S-scheme Fe2TiO5/BiVO4 nano-heterojunction with high visible-light photocatalytic performance was synthesized by an in-situ growth method. The optimized Fe2TiO5 (20 wt%)/BiVO4 composite exhibited remarkable photocatalytic activity and rapid degradation ability towards CIP (50 mg/L) with the addition of H2O2 (20 mM), achieving a removal efficiency of 94.2 % within 90 mins. This performance is significantly superior to that of pure BiVO4 (43.8 %) or pure Fe2TiO5 (48.2 %). The S-scheme heterojunction formed between Fe2TiO5 and BiVO4 facilitates efficient charge separation, and preserves the powerful photogenerated electrons in CB of Fe2TiO5 and holes in the VB of BiVO4, contributing to the fast degradation of CIP. The synergistic effects of the S-scheme heterojunction and H2O2 activation account for the excellent performance of Fe2TiO5/BiVO4 photocatalyst. The prepared photocatalyst demonstrates remarkable efficiency, non-selectivity, exceptional stability, and adaptability to various environmental conditions. This study proposes a novel approach for designing and synthesizing photo-assisted Fenton-like S-scheme photocatalysts for efficient removal of organic pollutants in wastewater.

Crystal growth, Hirshfeld analysis, optical, thermal, mechanical, and third-order non-linear optical properties of Cyclohexylammonium picrate (CHAP) single crystal

The organic single crystals of Cyclohexylammonium picrate (CHAP) had been grown using the method of slow evaporation solution growth. A determination was made regarding the solubility of the substance. The crystal's lattice cell parameters and morphology were characterized using single-crystal X-ray diffraction and powder X-ray diffraction techniques. The HRXRD techniques were utilized to assess the crystal quality. The functional groups of CHAP material were identified through the use of FT-IR and FT-Raman analysis. A Hirshfeld surface analysis was performed to investigate the formation of hydrogen bonds between N–H⋯O and C–H⋯O molecules. The grown crystals were examined in optical and thermal investigations utilizing UV–visible and TGA, DSC techniques. Mechanical analysis is used to quantify surface properties, such as work hardening coefficient and void volume. Z-scan analysis was utilized to calculate the non-linear refractive index (n2), nonlinear absorption (β), and third-order non-linear susceptibility (χ3).

Salt-Assisted Vapor-Liquid-Solid Growth of 1D van der Waals Materials.

The method of salt-assisted vapor-liquid-solid (VLS) growth is introduced to synthesize 1D nanostructures of trichalcogenide van der Waals (vdW) materials, exemplified by niobium trisulfide (NbS3). The method uses a unique catalyst consisting of an alloy of Au and an alkali metal halide (NaCl) to enable rapid and directional growth. High yields of two types of NbS3 1D nanostructures, nanowires and nanoribbons, each with sub-ten nanometer diameter, tens of micrometers length, and distinct 1D morphology and growth orientation are demonstrated. Strategies to control the location, size, and morphology of growth, and extend the growth method to synthesize other transition metal trichalcogenides, NbSe3 and TiS3, as nanowires are demonstrated. Finally, the role of the Au-NaCl alloy catalyst in guiding VLS synthesis is described and the growth mechanism based on the relationships measured between structure (growth orientation, morphology, and dimensions) and growth conditions (catalyst volume and growth time) is discussed. These results introduce opportunities to expand the library of emerging 1D vdW materials to make use of their unique properties through controlled growth at nanoscale dimensions.

Multilayered BCST/PZT thin films on GaN substrate for ultraviolet photodetector applications

In the realm of photodetection, there has been growing interest in Ferroelectric/semiconductors heterostructures due to the interfacial charge coupling resulting from ferroelectric polarization. In this study, we created a thin film consisting of alternating layers of Ba0.86Ca0.14Ti0.9Sn0.1O3 and PbZr0.52Ti0.48O3 (referred to as BCST/PZT) using a sol-gel growth method on a (0001) GaN/c-sapphire template. Our objective was to examine the impact of these films on the optoelectronic properties of ferroelectric/GaN heterojunctions. Our findings indicate that the BCST/PZT multilayer films possess improved ferroelectric properties. Furthermore, the multilayer structure demonstrates outstanding optoelectronic performance compared to the individual BCST/GaN or PZT/GaN structures, particularly within the 1 V to 3 V bias range. Notably, the multilayer thin film/GaN devices exhibit a responsivity of 121.4 mA/W and a detectivity of 1.44 × 1011 Jones under a 1 V bias voltage. In contrast to other GaN-based materials documented in the literature, our straightforward sol-gel techniques yielded devices exhibiting UV photodetection characteristics that are either comparable to or superior than those reported.

A highly sensitive SERS optical fiber probe with PSS modified gold nano-bipyramids for trace detection of water contamination

The combination of surface-enhanced Raman scattering (SERS) and optical fiber has led to the development of SERS optical fiber probe, which demonstrates potential for real-time, in-situ, and flexible detection of water contamination. In this paper, a highly sensitive SERS optical fiber probe of gold nano-bipyramids (Au NBPs) was successfully developed for the first time. The Au NBPs were controllably synthesized by a heat-treated seed growth method. Surface modification of the Au NBPs was carried out by adding poly (sodium 4-styrenesulfonate) (PSS) instead of hexadecyl trimethyl ammonium bromide (CTAB), which changed the Zeta potential of the Au NBPs solution from positive to negative. The SERS properties of the Au NBPs can be significantly enhanced by optimizing the parameters of PSS content. The optical fiber end face was pretreated with silane coupling agent to introduce amino groups and exhibit positive charge. As a result, highly sensitive SERS optical fiber probes were prepared through electrostatic adsorption of the Au NBPs. The performance of the SERS optical fiber probe was evaluated. The crystalline violet (CV) limit concentration of 10−10 mol/L was detected by the optimized SERS optical fiber probe with satisfactory reproducibility and stability. Additionally, a limit concentration of 10−5 mol/L for thiram could also be detected by the SERS optical fiber probe. Finally, the SERS enhancement mechanism was further discussed. The finite element method was utilized to analyze the electromagnetic field distribution of Au NBPs, optical fibers, and SERS optical fiber probes, theoretically explaining the performance advantages of Au NBPs SERS optical fiber probes. Based on our results, the Au NBPs SERS optical fiber probe holds significant value for trace detection of water contamination and biomolecules.

Rate-dependent augmented finite element method for fast arbitrary crack growth

Experimental observations indicate that fast crack growth often exhibits a rate dependency, which is caused by the viscosity of the material and the dissipation of energy resulting from the branching of microcracks. To address this phenomenon in simulation modeling, this study introduces a rate-dependent augmented finite element method designed for analyzing fast arbitrary crack growth. The method utilizes the maximum principal stress criterion to simulate arbitrary crack growth and predict the path of crack growth. The elements where crack growth is expected are divided into subelements, and they are re-assembled by incorporating rate-dependent cohesive elements between them to construct augmented finite elements. The cohesive elements are based on a rate-dependent trapezoid traction–separation relationship, where the critical traction and fracture toughness are modeled as functions of the separation rate and crack growth speed. The augmented finite elements only contain external nodal degrees of freedom (DoFs), while internal nodal DoFs are condensed. They can be utilized as conventional elements. A numerical algorithm based on the proposed method was developed in this article, and it was implemented in ABAQUS via user element subroutine. The effectiveness of this method and algorithm is validated through an example of dynamic crack growth in a double cantilever beam. The results demonstrate agreement with experimental and computational findings reported in the literature. Additionally, the method was applied to other structures, yielding reasonable outcomes. Analysis of these examples confirms the method’s utility in predicting fast arbitrary crack growth under dynamic load conditions.

Resistivity size effect in epitaxial face-centered cubic Co(001) layers

Metastable face-centered cubic (fcc) Co layers are deposited by reactive magnetron sputtering in 5 mTorr N2 at 400 °C followed by vacuum annealing at 500 °C. The resulting phase-pure Co(001)/MgO(001) layers contain negligible nitrogen and exhibit a surface roughness <0.8 nm and a cube-on-cube epitaxial relationship with the substrate with Co[100]ǁMgO[100]. The measured resistivity vs thickness d = 10–1000 nm indicates a bulk resistivity ρo = 6.4 ± 0.3 μΩ cm for fcc Co at room temperature and ρo = 1.3 ± 0.1 μΩ cm at 77 K, and an effective electron phonon mean free path λ = 27 ± 2 nm and 79 ± 6 nm at 295 and 77 K, respectively. The resulting ρo × λ benchmark quantity is 3–5 times larger than that predicted from first principles, suggesting a breakdown of the Fuchs–Sondheimer model at small dimensions. The overall results indicate that fcc Co exhibits no intrinsic conductance benefit over stable hcp Co nor conventional Cu for narrow interconnects. The developed method for growth of epitaxial fcc Co(001) layers provides opportunities to study this metastable material for potential spintronic applications.

On-Substrate Fabrication of CsPbBr3 Single-Crystal Microstructures via Nanoparticle Self-Assembly-Assisted Low-Temperature Sintering.

The growth of all-inorganic perovskite single-crystal microstructures on substrates is a promising approach for constructing photonic and electronic microdevices. However, current preparation methods typically involve direct control of ions or atoms, which often depends on specific lattice-matched substrates for epitaxial growth and other stringent conditions that limit the mild preparation and flexibility of device integration. Herein, we present the on-substrate fabrication of CsPbBr3 single-crystal microstructures obtained via a nanoparticle self-assembly assisted low-temperature sintering (NSALS) method. Sintering guided by self-assembled atomically oriented superlattice embryos facilitated the formation of single-crystal microstructures under mild conditions without substrate dependence. The as-prepared on-substrate microstructures exhibited a consistent out-of-plane orientation with a carrier lifetime of up to 82.7 ns. Photodetectors fabricated by using these microstructures exhibited an excellent photoresponse of 9.15 A/W, and the dynamic optical response had a relative standard deviation as low as 0.1831%. The discrete photosensor microarray chip with 174000 pixels in a 100 mm2 area showed a response difference of less than 6%. This method of nanoscale particle-controlled single crystal growth on a substrate offers a perspective for mild-condition preparation and in situ repair of crystals of various types. This advancement can propel the flexible integration and widespread application of perovskite devices.