Diamond and Related Materials最新文献

B, Ni, and CNTs co-doped diamond-like carbon (B, Ni, CNTs co-doped DLC) films were synthesized on the surface of AZ91D magnesium alloy by electrodeposition with low cost. The effect of CNTs concentration on the microstructure, microhardness, tribological properties and corrosion behavior of B, Ni, CNTs co-doped DLC films were evaluated. Results revealed that the B, Ni, CNTs co-doped DLC films were hydrogenated amorphous carbon films. Raman spectra showed that the D and G peaks of DLC films appear near 1330 cm⁻¹ near 1580 cm⁻¹, respectively. When the concentration of CNTs was 0.25 g/L, the CNTs were evenly distributed, making the structure of co-doped DLC films uniform, dense and flat. At this time, since the combined synergistic effect of reticulation of CNTs and the network-like structure of DLC films, the microhardness of the co-doped DLC films reached the maximum of 248.3 HV. The tubular structure of CNT supports and lubricates the substrate, which weakens the frictional resistance between the friction partners and reduces the friction coefficient to the lowest value of 0.128. The wear loss was the minimum with 0.1 × 10⁻⁵ kg/m, which is the result of CNTs exerting their self-lubricating properties to improve the wear resistance of the DLC film so that less wear occurs during the repeated friction process. Meanwhile, the positive corrosion potentials of B, Ni, CNTs co-doped DLC films indicate that the three elements co-doped DLC films can improve the corrosion resistance of magnesium alloy substrates.

Clozapine is vital for managing schizophrenia and other psychiatric disorders. As a potent medication with risks of severe side effects, accurate detection ensures effective treatment monitoring, patient safety, and optimization of therapeutic outcomes. Herein, niobium carbide two-dimensional transition metal carbides (Nb₂CT_x MXene) was prepared by etching niobium aluminum carbide (Nb₂AlC), which was next partially oxidized by a hydrothermal method to niobium oxide (Nb₂O₅)/Nb₂CT_x and ultrasonically bound to carboxylated multi-walled carbon nanotubes (MWCNTs-COOH). It was modified onto a glassy carbon electrode for the detection of the antipsychotic drug clozapine ingested by humans. The morphology and electrochemical properties of MXene-based nanocomposite electrode were verified by scanning electron microscopy, X-ray diffractometry, Raman, cyclic voltammetry and electrochemical impedance characterization methods. The results showed that electrode responded well to clozapine solutions, with good linearity (R² = 0.9979 and 0.9995) of the peak currents with clozapine concentrations (0.01–1.0 μM and 1.0–10.0 μM) and that this sensor had good immunity, repeatability, reproducibility and stability. The limit of detection was 8.38 nM and the recovery was 92.5 % ~ 106.5 % in real serum and urine samples. The MXene-based sensors offer excellent analytical performance and hold promise for cost-effective generalisation to the detection of nanomolar clozapine in a variety of clinical applications.

The main purpose of this research is to form highly effective and novel electrocatalysts for water splitting procedure, a pivotal step in the generation of sustainable energy. Cost-effective metal oxides exhibited superior benefits compared to alternative materials when used for oxygen evolution reactions (OER) in alkaline electrolyte. Our study focuses on the preparation of ZnAl₂O₄@g-CN composite by utilizing hydrothermal approach for electrocatalytic water splitting. The electrocatalytic potential of prepared electrocatalyst was observed by a comprehensive series of tests. Numerous electrochemical approaches such as chronoamperometry and electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were implemented to analyze catalytic procedure and durability in basic medium. The electrocatalytic tests of ZnAl₂O₄@g-CN composite reveal a remarkable overpotential of 209 mV, enabling the attainment of current density (C_d) 10 mA/cm². Additionally, the composite shows significantly lower Tafel value (36 mV/dec) and has remarkable durability for 30 h. These characteristics mutually designate that electrocatalyst is well-suited for OER procedure. Therefore, the fabricated composite exhibited excellent efficacy in OER procedure as well as for several other upcoming applications.

A relatively simple metasurface structure is proposed to achieve a dynamically tunable slow light effect. The metasurface consists of two horizontal graphene strips and two vertical continuous graphene strips. Strong interference between the bright and dark modes enables the metasurface to generate a significant triple plasmon-induced transparency (PIT). Varying the coupling distance between the horizontal strips, double-PIT and triple-PIT can be transformed into each other. During the reduction of the transparent window, electromagnetic waves undergo strong phase changes, resulting in a higher group index. After structural optimization, the maximum time delay and group index can be as high as 2.624 ps and 3934, surpassing comparable slow light devices. The proposed patterned graphene metasurface provides theoretical guidance for designing high-performance slow light devices for optical storage, nonlinear optics and quantum optics.

This work illustrates the production of highly electrochemically active graphene by liquid phase exfoliation technique for ultrasensitive electrochemical sensors. An airless high-pressure spray technique was designed to exfoliate bulk natural graphite into nm-scaled flakes (referred as HP50). Transmission electron microscopy, Raman and X-ray photoelectron spectroscopy studies reveal that the HP50 sample has a mixed structure composed of amorphous carbon and a few-layer graphene fraction with high amount of edge plane defects. The HP50 flakes are drop cast on glassy carbon electrodes to test the simultaneous and selective electrochemical detection of hydrogen peroxide, ascorbic acid, and dopamine. In cyclic voltammetry measurements, hydrogen peroxide reduces at −0.2 V vs Ag/AgCl (1 M), while ascorbic acid and dopamine oxidize at 0.1 V vs Ag/AgCl (1 M) and 0.3 V vs Ag/AgCl (1 M), respectively. Linear sweep voltammetry demonstrates high sensitivity (164, 739, and 3357 μA mM⁻¹ cm⁻²) and low limit of detection (15, 1.7, and 2.1 μM) for the three analytes, respectively. Interference studies confirm a high sensitivity and selectivity towards the different chemical species. The HP50-based multianalyte sensors are also tested against different environmental and commercial samples, illustrating their viability in practical applications.

Recent studies found nanostructured carbon particles (NCPs) in various food products due to advanced cooking methods that carbonized the food components. The NCPs are formed in the food production processes, but their potential health effects are still unknown. Hence, this work aimed to isolate nanostructured carbon particles from processed foods and investigate their impact on the cytotoxic features using Human Mesenchymal Stem Cells (hMSCs) as a model. The NCPs were isolated through combined techniques, including centrifugation, dialysis, and filtration. The isolated NCPs morphological features were examined using transmission electron microscopy (TEM). In TEM images, we observed 5–20 nm in diameter dot-like carbon nanostructures. To predict the NCP's toxicological profile, we evaluated the NCP's impact on hMSC viability, mitochondrial health, and expression of genes. The NCPs reduce 18 % and 32 % of hMSCs viability at 400 μg/mL treatment for 24 and 48 h, respectively. Also, NCP exposure triggers alterations in the expression of GSR and NFKB1. These findings suggest that NCPs present in processed foods can influence the gene expression of hMSCs and moderately affect cellular processes. The NCPs could apply to biomedical applications, including bio-imaging and antioxidant therapy.

This study focuses on the development of hydrophobic layer on Portland cement using graphenoid materials to enhance impermeability and hydrophobicity. X-ray diffraction analysis indicated that characteristic peaks associated with concrete, such as ettringite, calcium hydroxide, and calcite, remained intact. The application of graphenoid material produced by non-thermal plasma resulted in the formation of carbonaceous structures, minimally affecting the overall cement structure. Raman spectroscopy provided detailed insights into the composition, highlighting the presence of specific and indicating boundary defects. Moreover, contact angle measurements confirmed a substantial increase in hydrophobicity for the graphene-coated cement, with an average angle of 117° ± 4.72° demonstrated graphenoid material layers deposited over structural defects, effectively waterproofing and enhancing local hydrophobicity.

Materials made of amorphous carbon that includes nitrogen have been extensively researched for use as negative electrodes in systems that store energy like lithium-ion batteries (LIBs). Graphene platelets (GP) covered with polyaniline (PANi) were effectively created through polymerization and utilized as anode material for lithium-ion batteries. The prepared AGP composite material, utilized in lithium-ion batteries as an anode material (AM), was evaluated for its electrochemical properties. It produced a specific capacity (SC) of 450 mAhg⁻¹ for 160 electrochemical cycles at a current density (CD) of 100 mAg⁻¹ and 256 mAhg⁻¹ for 500 cycles at a high current density (CD) of 1 Ag⁻¹. These suggest that it could be a good option for the anode material (AM) in lithium-ion batteries (LIBs).

Carbonaceous materials have great prospects in microwave absorption due to their lightweight and corrosion resistance. However, their high conductivity leads to poor impedance matching, posing a significant challenge for obtaining outstanding microwave absorption (MA) materials from carbonaceous materials. In this work, the core-shell ZnO/C nanorods (ZCNs) are prepared by covering conductive carbon on the surface of ZnO nanorods through a simple stirring process in ambient temperature and calcination treatment. The thickness of carbon shell is carefully regulated to realize appropriate impedance matching and strong microwave dissipation capability. ZCN with 30.2 nm of carbon shell achieves outstanding microwave absorption in low frequency and broadband microwave absorption because of the synergies of optimized impedance matching and enhanced dielectric loss: the reflection loss of 49.9 dB at 6.32 GHz, and the effective absorption bandwidth of 6.4 GHz at a corresponding thickness of 2.0 mm. RCS simulation results have verified its excellent performance in practical application. This study proposes a simple and effective idea for the efficient utilization of carbonaceous materials in microwave absorption.

Negatively charged nitrogen-vacancy (NV⁻) centers in diamond produce a characteristic optical zero-phonon line (ZPL) at 637 nm. This emission line can be observed under optical excitation (i.e. photoluminescence), but is rarely observed under electron excitation (i.e. cathodoluminescence). This study reports that low-temperature (80 K) and low energy (5 keV) cathodoluminescence spectroscopy is able to detect emission peak or spectral dip at the ZPL of NV⁻ centers. The spectral dip was observed in the diamond samples with high concentration of NV⁻ centers produced by high-energy (2 MeV) e-beam (EB) irradiation. The effects of EB irradiation fluence, NV⁻ centers concentration and substitutional nitrogen concentration on the formation of spectral dip were discussed, and a model based on the NV⁻ absorption of NV⁰ emission sideband is proposed.