Search Results (25)

Non-stoichiometric copper sulfide (Cu_2-xS) nanomaterials are promising antibacterial agents, but the role of morphology in regulating their bactericidal performance remains poorly understood. Herein, we rationally design two types of Cu_2-xS nanostructures, namely nanoplates (NPs) and superparticles (SPs). Both materials were prepared via a ligand-directed synthesis method with the comparable sizes, surface ligands, and crystal phase. The antibacterial behaviors of Cu_2-xS NPs and Cu_2-xS SPs against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were investigated under dark and 808 nm near-infrared (NIR) light irradiation. The results showed that under NIR light irradiation, Cu_2-xS SPs exhibit a markedly higher bactericidal efficiency against both E. coli and S. aureus than Cu_2-xS NPs, leading to almost complete eradication of bacterial colonies. Notably, S. aureus shows more sensitive than E. coli, and significant growth inhibition is observed even in the absence of laser irradiation. Mechanistic investigations reveal that hierarchical assembly of primary nanoparticles in SPs can promote multiple internal light scatterings, thereby significantly enhancing light harvesting efficiency and further improving the photothermal conversion efficiency. In addition, the SPs exhibited higher peroxidase-like activity, resulting in enhanced reactive oxygen species (ROS) generation and aggravated oxidative damage, and the accelerated Cu²⁺ release kinetics strengthens ionic toxicity. Full article

Rouaite (Cu₂(OH)₃NO₃) long hexagonal multilayered nanoplates with high purity and high crystallinity were prepared from acidic reaction solution (pH = 4.4–4.8) with the assistance of ZnO. The ZnO-assisted strategy is remarkably different from the conventional synthetic protocol that was regularly carried out in alkaline solution (pH > 11). The rouaite multilayer nanoplates displayed exceptionally high catalytic activity in the catalytic wet peroxide oxidation (CWPO) of Congo red (CR). The catalytic efficiency for CR decolorization achieved an impressive 96.3% in 50 min under near-neutral (pH = 6.76) and ambient conditions (T = 20 °C, p = 1 atm), without increasing the temperature and/or decreasing the pH value to acidic region (pH = 2–3) as is commonly employed in CWPO process for improved degradation efficiency. Full article

The catalytic esterification of levulinic acid (LA) to methyl levulinate (ML) was investigated using copper molybdate (Cu₃(MoO₄)₂(OH)₂) as a heterogeneous catalyst. The catalyst, synthesized via chemical precipitation, exhibited a monoclinic structure with self-assembled nanoplates forming spherical mesostructures. Structural characterization confirmed its high crystallinity, while textural analysis revealed a BET surface area of 70.55 m² g⁻¹ with pore sizes in the nanometric range (1–6 nm). The catalytic performance was systematically evaluated under varying reaction conditions, including temperature, catalyst dosage, reaction time, methanol-to-LA molar ratio, alcohol type, and catalyst reusability. Optimal conversion of 99.3% was achieved at 100 °C, a 1:20 methanol-to-LA molar ratio, 5% catalyst loading, and a reaction time of 4 h. Comparative analysis with other heterogeneous catalysts demonstrated superior efficiency and stability of Cu₃(MoO₄)₂(OH)₂, with minimal activity loss over four reuse cycles (final conversion of 77.1%). Mechanistic insights suggest that its high activity is attributed to Lewis and Brønsted acid sites, facilitating efficient esterification. This study underscores the potential of copper molybdate as a sustainable and recyclable catalyst for biofuel additive synthesis, advancing green chemistry strategies for biomass valorization. Full article

The detection of dopamine is of great significance for human health. Herein, Pd nanoparticles were loaded on Cu nanoplates (Pd/Cu NPTs) by a novel liquid phase reduction method. A novel dopamine (DA) electrochemical sensor based on the Pd NPs/Cu/glass carbon electrode (Pd/Cu NPTs/GCE) was constructed. This sensor showed a wide linear range of 0.047 mM to 1.122 mM and a low limit of detection (LOD) of 0.1045 μM (S/N = 3) for DA. The improved performance of this sensor is attributed to the obtained tiny Pd nanoparticles which increase the catalytic active sites and electrochemical active surface areas (ECSAs). Moreover, the larger surface area of two–dimensional Cu nanoplates can load more Pd nanoparticles, which is another reason to improve performance. The Pd/Cu NPTs/GCE sensor also showed a good reproducibility, stability, and excellent anti–interference ability. Full article

One of the main climate change-related variables limiting agricultural productivity that ultimately leads to food insecurity appears to be drought. With the use of a recently discovered nanopriming technology, seeds can endure various abiotic challenges. To improve seed quality and initial growth of 8-day-old field pea seedlings (cv. NS Junior) under optimal and artificial drought (PEG-induced) laboratory conditions, this study aimed to assess the efficacy of priming with three different nanomaterials: Nanoplant Ultra (Co, Mn, Cu, Fe, Zn, Mo, and Se), Nanoplant Ca-Si (Ca, Si, B, and Fe), and Nanoplant Sulfur (S). The findings indicate that nanopriming seed treatments have a positive impact on seed quality indicators, early plant growth, and drought resilience in field pea plants established in both optimal and drought-stressed conditions. Nevertheless, all treatments showed a positive effect, but their modes of action varied. Nanoplant Ultra proved to be the most effective under optimal conditions, whereas Nanoplant Ca-Si and Nanoplant Sulfur were the most efficient under drought stress. After a field evaluation, the examined comprehensive nanomaterials may be utilized as priming agents for pea seed priming to boost seed germination, initial plant growth, and crop productivity under various environmental conditions. Full article

Thin films consisting of quadrilateral nanoplates of CuO on the surface of a Cu plate were successfully synthesized in a two-dimensional microspace by the hydrothermal oxidation of a Cu plate using aqueous (NH₄)₂S₂O₈ solution as the oxidizer. Selective crystal growth was clearly observed in the two-dimensional microspace formed between the Al₂O₃ and the Cu plates, and a highly crystalline CuO quadrilateral nanoplate thin film was formed on the surface of the Cu plate that faced the Al₂O₃ plate. Similar experiments were performed by replacing the Al₂O₃ plate with Cu, Ti, or SUS316L plates as the substrate, to investigate the effect of the substrate facing the Cu plate. Using different substrates resulted in significant differences in the morphology of the CuO thin film on the Cu plate facing the substrate. The present study demonstrates that the use of a two-dimensional microspace can be extremely effective in controlling the nanostructure of thin films. Full article

The necessity for complex functionality materials is increasing due to the emergence of high-tech technologies and the deepening needs of B-to-B companies in the industry. Study on advanced multifunctional materials is also increasing due to interest in fields such as the the Internet of Things (IOT), Fourth Industrial Revolution, and artificial intelligence (AI). Nanomaterials have the advantage of having a large surface area, making it easier to express more efficient properties, and they have been widely applied recently in various fields. When designing new materials for specific applications, it is often important to control the shape, size distribution, surface properties, dispersion, and agglomeration stability of synthetic nanoparticles, as well as the elemental and nanocrystalline compositions of the materials. Nanomaterials have infinite potential, but there are not many cases of collection and structural classification. Therefore, I attempted to conduct an in-depth systematic review by categorizing nanomaterials into nanoparticles, nanoplates, nanowires, and nanorolls according to their nanostructures. Additionally, the representative materials of nanowires include CuNW (copper nanowire), AgNW (silver nanowire), and GaAsP single nanowire. Moreover, nanoroll-type materials include SWCNTs (single-walled carbon nanotubes), DWCNTs (double-walled carbon nanotubes), and MWCNTs (multi-walled carbon nanotubes). In conclusion, this study, through a systematic review, is intended to provide a cornerstone for application plans when designing cutting-edge chemosensors. Full article

A magnesium–aluminum-layered double hydroxide (Mg-Al LDH) with a nano-lamellar morphology was prepared by using a homogeneous precipitation and hydrothermal method, and a calcination product (Mg-Al LDO) of the Mg-Al LDH was also obtained in this work. The XRD, TEM, SEM, FTIR, N₂ ad/desorption, and TG-DTG techniques were employed to characterize the microstructures, morphologies, and thermostability levels of these two materials in detail. The results showed that both the Mg-Al LDH and Mg-Al LDO had mesoporous structures and nanoplate morphologies, with diameters of 50~200 nm. The Mg-Al LDH was transformed into Mg-Al LDO at 773 K in an air atmosphere. The adsorption properties of the Mg-Al LDH were investigated systematically with a copper chloride solution as a simulated waste. The experimental results demonstrated that the pH value of the solution had an obvious influence on its Cu²⁺ adsorption capacity, and the optimal pH value was approximately 5.0. The adsorption kinetics results showed that the Mg-Al LDH had a rapid adsorption rate, and the equilibrium adsorption capacity was 62.11 mg/g. Additionally, the Cu²⁺ adsorption could be commendably described using a pseudo-second-order model, demonstrating that the adsorption behavior is regulated by chemical sorption. The adsorption thermodynamic results indicated that the adsorption process was spontaneous at temperatures above 318 K. Moreover, the ΔG⁰ values decreased as the temperature was raised, which indicated that a higher temperature can cause a greater impetus for Cu²⁺adsorption. In addition, the positive values of the ΔH⁰ indicated that the Cu²⁺ adsorption was endothermic, and the positive ΔS⁰ values revealed an increase in the confusion at the solid–liquid interface of the adsorbent. Full article

This work investigates the feasibility of increasing the electric conductivity of an AA1370 aluminium wire by using pulse-reverse electrodeposition to realize Cu-Graphene composite coating. The graphene adopted was in the form of nanoplates (GnP). To study the effects of plating parameters, a 2³ factorial plan was developed and tested. During the tests, the following process parameters were varied: the current density, the frequency and the duty cycle. The ANalysis Of VAriance (ANOVA)) was adopted to evaluate their influence on the coated wires’ morphology and electrical conductivity resistance. The results show that all the tested conditions allow good compactness to the coating, and the amount of graphene is well incorporated within the microstructure of the copper deposit. In addition, in the best conditions, the electrical resistivity decreases up to 3.4% than the uncoated aluminum. Full article

There are growing interests in the development of bifunctional semiconducting nanostructures for photocatalysis and real-time monitoring of degradation process on catalysts. Defect engineering is a low-cost approach to manipulating the properties of semiconductors. Herein, we prepared CuS nanoplates by a hydrothermal method at increasing amounts of thioacetamide (CS-1, CS-2, and CS-3) and investigated the influence of sulfur vacancy (V_s) on surface-enhanced Raman spectroscopy (SERS) and photocatalysis performance. SERS intensity of 4-nitrobenzenethiol on CS-3 is 346 and 17 times that of CS-1 and CS-2, respectively, and enhancement factor is 1.34 × 10⁴. Moreover, SERS is successfully applied to monitor the photodegradation of methyl orange. In addition, CS-3 also exhibited higher efficiency of Cr(VI) photoreduction than CS-1 and CS-2, and removal rate is 88%, 96%, and 73% under 2 h UV, 4 h visible, and 4 h near-infrared illumination, respectively. A systematic study including electron paramagnetic resonance spectra, photoelectrochemical measurements, and nitrogen adsorption isotherms were conducted to investigate the underlying mechanism. This work may help to understand the impact of vacancy defect on SERS and photocatalysis, and provide an effective and low-cost approach for the design of multifunctional materials. Full article

Using safe and environmentally benign materials is considered one of the green chemistry approaches to avoid waste production. This research reported the biogenic synthesis of CuO nanoplates using Saussurea costus root extract assisted by a microwave sample preparation system. The phytochemical contents in the Saussurea costus root aqueous extract work as the reducing and capping agents for the nanoparticles. The biosynthesized CuO nanoplates were analyzed using UV–Vis spectroscopy, FT-IR, XRD, HR-TEM, DLS, FESEM, and EDS techniques. According to the HR-TEM and FE-SEM results, the CuO nanoparticles exhibited a plate-like shape with a mean size of 29 nm. Furthermore, the XRD results showed a typical agreement with the pattern of the monoclinic phase of copper oxide. The catalytic efficiency of the CuO nanoplates in the reduction of 4-nitrophenol to 4-aminophenol using NaBH₄ was examined in terms of environmental catalytic activity. The reaction time took less than 10 min. Thus, CuO nanoplates synthesized via Saussurea costus root aqueous extract show high catalytic-activity potential for the environmental catalytic application of the removal of nitro pollutants. Full article

Plasmonic nanostructures, featuring near infrared (NIR)-absorption, are rising as efficient nanosystems for in vitro photothermal (PT) studies and in vivo PT treatment of cancer diseases. Among the different materials, new plasmonic nanostructures based on Cu_2−xS nanocrystals (NCs) are emerging as valuable alternatives to Au nanorods, nanostars and nanoshells, largely exploited as NIR absorbing nanoheaters. Even though Cu_2−xS plasmonic properties are not linked to geometry, the role played by their size, shape and surface chemistry is expected to be fundamental for an efficient PT process. Here, Cu_2−xS NCs coated with a hydrophilic mesoporous silica shell (MSS) are synthesized by solution-phase strategies, tuning the core geometry, MSS thickness and texture. Besides their loading capability, the silica shell has been widely reported to provide a more robust plasmonic core protection than organic molecular/polymeric coatings, and improved heat flow from the NC to the environment due to a reduced interfacial thermal resistance and direct electron–phonon coupling through the interface. Systematic structural and morphological analysis of the core-shell nanoparticles and an in-depth thermoplasmonic characterization by using a pump beam 808 nm laser, are carried out. The results suggest that large triangular nanoplates (NPLs) coated by a few tens of nanometers thick MSS, show good photostability under laser light irradiation and provide a temperature increase above 38 °C and a 20% PT efficiency upon short irradiation time (60 s) at 6 W/cm² power density. Full article

Compared with gold and silver, cheap copper has attracted more attention and can potentially be applied in non-enzymatic electrochemical sensors due to its excellent conductivity and catalytic activity. In this paper, copper nanoplates were rapidly synthesized using copper bromide as the copper precursor, polyethyleneimine as the stabilizer, and ascorbic acid as a reducing agent in the presence of silver nanoparticles at a reaction temperature of 90 °C. The Cu nanoplates with an average side length of 10.97 ± 3.45 μm were obtained after a short reaction time of 2 h, demonstrating the promoting effect of an appropriate amount of silver nanoparticle on the synthesis of Cu nanoplates. Then, the electrochemical dopamine sensor was constructed by modifying a glass carbon electrode (GCE) with the Cu nanoplates. The results obtained from the test of cyclic voltammetry and chronoamperometry indicated that the Cu-GCE showed a significant electrochemical response for the measurement of dopamine. The oxidation peak current increased linearly with the concentration of dopamine in the range of 200 µmol/L to 2.21 mmol/L, and the corresponding detection limit was calculated to be 62.4 μmol/L (S/N = 3). Furthermore, the anti-interference test showed that the dopamine sensor was not affected by a high concentration of ascorbic acid, glucose, uric acid, etc. Therefore, the constructed Cu-GCE with good selectivity, sensitivity, and stability possesses a high application value in the detection of dopamine. Full article

Copper selenide-sulfide nanostructures were synthesized using metal-organic chemical routes in the presence of Cu- and Se-precursors as well as S-containing compounds. Our goal was first to examine if the initial Cu/Se 1:1 molar proportion in the starting reagents would always lead to equiatomic composition in the final product, depending on other synthesis parameters which affect the reagents reactivity. Such reaction conditions were the types of precursors, surfactants and other reagents, as well as the synthesis temperature. The use of ‘hot-injection’ processes was avoided, focusing on ‘non-injection’ ones; that is, only heat-up protocols were employed, which have the advantage of simple operation and scalability. All reagents were mixed at room temperature followed by further heating to a selected high temperature. It was found that for samples with particles of bigger size and anisotropic shape the CuSe composition was favored, whereas particles with smaller size and spherical shape possessed a Cu_2−xSe phase, especially when no sulfur was present. Apart from elemental Se, Al₂Se₃ was used as an efficient selenium source for the first time for the acquisition of copper selenide nanostructures. The use of dodecanethiol in the presence of trioctylphosphine and elemental Se promoted the incorporation of sulfur in the materials crystal lattice, leading to Cu-Se-S compositions. A variety of techniques were used to characterize the formed nanomaterials such as XRD, TEM, HRTEM, STEM-EDX, AFM and UV-Vis-NIR. Promising results, especially for thin anisotropic nanoplates for use as electrocatalysts in nitrogen reduction reaction (NRR), were obtained. Full article

Ru is a key component of electrocatalysts for hydrogen evolution reaction (HER), especially in alkaline media. However, the catalytic activity and durability of Ru-based HER electrocatalysts are still far from satisfactory. Here we report a solvothermal approach for the synthesis of PdCuRu porous nanoplates with different Ru compositions by using Pd nanoplates as the seeds. The PdCuRu porous nanoplates were formed through underpotential deposition (UPD) of Cu on Pd, followed by alloying Cu with Pd through interdiffusion and galvanic replacement between Cu atoms and Ru precursor simultaneously. When evaluated as HER electrocatalysts, the PdCuRu porous nanoplates exhibited excellent catalytic activity and durability. Of them, the Pd₂₄Cu₂₉Ru₄₇/C achieved the lowest overpotential (40.7 mV) and smallest Tafel slope (37.5 mV dec⁻¹) in an alkaline solution (much better than commercial Pt/C). In addition, the Pd₂₄Cu₂₉Ru₄₇/C only lost 17% of its current density during a stability test for 10 h, while commercial Pt/C had a 59.5% drop under the same conditions. We believe that the electron coupling between three metals, unique porous structure, and strong capability of Ru for water dissociation are responsible for such an enhancement in HER performance. Full article