ChemNanoMat最新文献

This study demonstrates a one-pot combustion synthesis of a type-II ZnO/CdMoO₄ heterojunction for highly efficient solar-driven hydrogen peroxide (H₂O₂) production. The optimized heterojunction exhibited a remarkable H₂O₂ generation rate of 332.86 μmol g⁻¹ h⁻¹ under simulated sunlight in the presence of methanol as a sacrificial agent, which is 3.2 times higher than that of pure ZnO. A series of characterization techniques (including XRD, SEM, TEM, XPS, UV-DRS) confirmed the successful formation of a close heterointerface with favorable staggered band alignment, which facilitates efficient charge separation and transfer. Mechanistic investigations revealed that the type-II heterojunction not only enhances the spatial separation of photogenerated electron–hole pairs but also promotes the two-electron oxygen reduction reaction for H₂O₂ production. This work offers a facile and scalable strategy for designing high-performance photocatalysts toward sustainable chemical synthesis.

The extended cycle life, excellent safety, and affordability of liquid metal batteries (LMBs) make them a viable option for large-scale stationary energy storage. However, stable stratification in the positive electrode inhibits convective mixing and causes extreme concentration polarization, which limits their discharge performance. In this study, we employ the finite element method to investigate the influence of external magnetic fields on the charge and discharge behavior of three-layer battery composed of Mg|LiF–LiBr|Te. Simulation results show that when a 120 mT magnetic field is applied, the discharge voltage rises by 24.43% at a current density of 300 mA cm⁻². Strong magnetic effects are observed at a higher current density of 700 mA cm⁻², where merely 80 mT magnetic field increases the discharge voltage by 62.66%. Additionally, we model and investigate three different LMB topologies with electrolyte thicknesses of 13 mm, 8 mm, and 5 mm. The voltage generated by the 5 mm-thick electrolyte LMB is 0.24 V higher than that of the 13 mm-thick electrolyte LMB by indicating that higher operating voltages are produced by thinner electrolytes. The findings enhance LMB performance and demonstrate that proper control of fluid flow is crucial for achieving better efficiency.

Graphitic carbon nitride (g-C₃N₄) holds great promise for photocatalytic hydrogen evolution, yet its efficiency is often limited by structural imperfections. Herein, we report a synthesis strategy that systematically engineers the polymerization process by controlling the intermediate-stage temperature and precursor (dicyandiamide, DCY) mass. The optimized sample (CCN-3.5), prepared at 240°C with 3.5 g of DCY, exhibits enhanced crystallinity and a remarkable hydrogen-evolution rate of 4355 μmol h⁻¹g⁻¹, which is 5.71 times that of the pristine polymer. This superior performance is attributed to the optimized structure that facilitates charge migration. In contrast, excess precursor was found to disrupt structural integrity and impair photocatalytic activity. This work highlights the critical role of polymerization control in developing high-performance g-C₃N₄ photocatalysts.

The oxygen evolution reaction (OER) limits the efficiency of electrochemical water splitting, making the development of low-cost, stable, and efficient catalysts a key challenge. In this work, nickel sulfide (NiS₂) nanostructures are grown on cone-shaped graphite electrodes and further modified via annealing in the presence of urea or NaH₂PO₂, introducing N or P element to alter the electronic environment around Ni²⁺ centers. Comprehensive characterization (XRD, FE-SEM, EDX, ICP-AES, XPS, and electrochemical techniques) confirms successful doping. The OER activity follows the trend N-NiS₂ > S-NiS₂ > P-NiS₂, correlating with the elemental electronegativity order of N > S > P. N-doped NiS₂ achieves a low overpotential of 260 mV at 10 mA cm⁻² and a Tafel slope of 53 mV dec⁻¹ in 1 M KOH. Urea-derived ammonia treatment creates a porous, high-surface-area architecture that enhances easy mass transport and catalytic efficiency. This simple, scalable strategy presents a cost-effective route to high-performance OER electrocatalysts.

Breast cancer is one of the most common malignancies. Despite the continuous advancement in therapeutic approaches, the emergence of multidrug resistance (MDR) in cancer cells against chemotherapeutic agents such as doxorubicin (DOX) has posed significant challenges to cancer treatment, highlighting an urgent need for the development of novel therapeutic strategies. Studies have demonstrated that the antisense oligonucleotide MB1 and microRNA MiR489 can inhibit the expression of P-glycoprotein and Smad3, respectively, which are associated with tumor MDR. Additionally, Cu²⁺ can disrupt cellular metabolism, trigger proteotoxic stress responses, and induce cuproptosis in cells. Therefore, in this study, functional nucleic acids (MB1 and miR489), Cu²⁺, and DOX were assembled into an integrated novel nanodrug system DOX/Cu²⁺@(MB1+MiR489). This system enables the delivery of membrane-impermeable functional nucleic acids into cells without the need for additional carriers, thereby enhancing the inhibitory effect of DOX on drug-resistant breast cancer cells. The results showed that DOX/Cu²⁺@(MB1+MiR489) reduced the IC₅₀ of DOX against MCF-7/ADM cells by 18-fold, significantly alleviated the resistance of drug-resistant breast cancer cells to DOX, and markedly inhibited their proliferation and migration.

Nitrite (NO₂⁻) is a notorious pollutant that has attracted increasing concern. This study synthesizes a novel polyoxometalate (POM) nanozyme Fe₂V₄O₁₃/V₂O₅and leverages its excellent catalytic performance to develop asmartphone-based platform for the highly sensitive detection of NO₂⁻. An n–n heterojunction formed between Fe₂V₄O₁₃ and V₂O₅ induces electron redistribution, generating a built-in electric field that improves the interaction between Fe₂V₄O₁₃ and substrates in peroxidase-like (POD-like) catalysis. Given the excellent POD-like activity of Fe₂V₄O₁₃/V₂O_5, NO₂⁻ can undergo diazotization reaction with the blue oxidized product ox-TMB generated by the nanozyme catalyzing 3,3,5,5-tetramethylbenzidine (TMB), resulting in the solution color changing from blue to yellow. Consequently, a visible colorimetry is developed for NO₂⁻ detection with a low limit of detection (LOD). The method has demonstrated excellent performance in the actual detection of NO₂⁻ in water samples. This work not only offers a new construction strategy to enhance the catalytic activity of POM-based nanozymes, but also provides an efficient and practical platform for the highly sensitive NO₂⁻ detection.

A facile one-step chemical vapor deposition (CVD) synthesis of multilayer graphene-wrapped copper nanoparticles (MLG-CuNPs), followed by an air-heating step to yield hollow clusters consisiting of partially oxidized-MLG-CuNPs, is investigated for the application on hydrogen evolution electrocatalysis. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) confirm the hollow architectures of the clusters, while X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses verify the surface oxidation of MLG-CuNPs and the retention of conductive copper core. The oxidized-MLG-CuNPs electrode can drive the hydrogen evolution reaction (HER) at a current density of 10 mA cm⁻² with a small overpotential of 290 mV and the Tafel slope of 151 mV dec.⁻¹; while the overpotential values of oxidized-MLG and oxidized-CuNPs electrode for reaching the same current density are 569 mV and 417 mV, respectively. Moreover, the oxidized-MLG-CuNPs electrode remains stable in an alkaline electrolyte for 500 cycles. These results highlight the potential of oxidized-MLG-CuNPs as an efficient and durable nonprecious electrocatalyst for hydrogen evolution in alkaline electrolyte.

The glycerol hydrogenolysis reaction is a critical connection between the biodiesel industry and the production of high-value-added chemicals, underscoring its significant development potential and substantial social value. In this study, we synthesized a series of Cu-ZrO₂-Al₂O₃ catalysts and investigated the influence of Al₂O₃ on the dispersion and chemical states of Cu species, the surface acid–base properties of the ZrO₂-Al₂O₃ support, and the overall catalytic performance for the selective hydrogenolysis of glycerol to 1,2-propanediol (1,2-PDO). The results indicate that the addition of appropriate amounts of Al₂O₃ enhances the dispersion of copper active sites within the catalyst, reduces both the quantity and strength of basic sites, and increases the proportion of medium-strength acid sites on the surface. The improved dispersion of Cu active species, an optimal balance between acidity and alkalinity, along with a synergistic interaction between Cu active species and surface acid–base sites collectively facilitates the smooth progression of the dehydration–hydrogenation pathway involving acidic sites. Consequently, the optimal Cu/ZrO₂-10%Al₂O₃ catalyst exhibits excellent catalytic capability and cyclic stability under mild conditions, achieving a glycerol conversion rate of 94.1% and a selectivity toward 1,2-PDO of 96.0%. Furthermore, these copper-based catalysts may have potential applications in the efficient exploitation and utilization of biomass resource.

This study presents a detailed simulation model of a perovskite solar cell (PSC) developed using the SCAPS (Solar Cell Capacitance Simulator) software, aiming to enhance photovoltaic technology performance. In this work, the model incorporates CH₃NH₃PbI₃ as the perovskite absorber layer, PCBM (phenyl-C₆₁-butyric acid methyl ester) as the electron-transport material, and Cu₂O as the hole-transport material. This combination was selected based on its suitability for achieving efficient charge transport in CH₃NH₃PbI₃-based PSCs. The optimization process investigated how changes in layer thickness, defect density, and doping concentration influence carrier recombination and device output parameters, providing a deeper understanding of performance-limiting factors. The simulated device achieves impressive performance metrics, including an open-circuit voltage of 1.4807  V, a short-circuit current density of 25.13 mA/cm², a fill factor of 86.95%, and a maximum power conversion efficiency of 32.36%. This work addresses a key challenge in PSCs by improving charge transport and enabling better stability by using robust inorganic Cu₂O as the hole-transport layer (HTL). Cu₂O is chosen here as an alternative to conventional organic HTLs due to its low cost and excellent thermal stability. Notably, the efficiency of the PSC has been significantly improved compared to previous models, mainly through the optimization of key material properties. This simulation study serves as a valuable tool for guiding the development of PSCs, offering both design strategies and a deeper understanding of the factors governing high energy conversion efficiency.

This study explores the photocatalytic performance of ZnO nanosponge (ZnO NSp), g-C₃N₄ nanosheet (g-C₃N₄ NSh), and their composite in degrading methylene blue (MB) under UV and visible-light irradiation. ZnO NSp displayed superior activity under UV light, achieving > 99% MB removal within 30 min and exhibiting the highest pseudo-first-order rate constant (0.124 min⁻¹), outperforming both g-C₃N₄ NSh and the composite. In contrast, under visible light, the g-C₃N₄ NSh/ZnO NSp composite achieved 98% degradation within 60 min, attributed to enhanced charge separation across the heterojunction interface. The photocatalytic efficiency was influenced by pH, with neutral to alkaline conditions favoring MB removal through improved catalyst stability and adsorption capacity. Radical scavenging experiments confirmed superoxide (O₂•⁻) and hydroxyl (HO•) radicals as the dominant reactive species driving degradation. These results demonstrate the complementary advantages of ZnO NSp and g-C₃N₄ NSh in different irradiation regimes and highlight the promise of their composite as an efficient, solar-responsive photocatalyst for wastewater remediation.