ChemNanoMat最新文献

A simple strategy for the conjugation of copper-1,4-benzene dicarboxylic (CuBDC) MOF with zinc oxide (ZnO) matrix for the fabrication of CuBDC/ZnO is presented—a tandem electrocatalyst with excellent electrochemical stability and electrocatalytic performance toward selective electroreduction of CO₂ (ERCO₂). The tandem action and easy mass transport in mesostructured CuBDC/ZnO are demonstrated to facilitate efficient, facile, and selective production of methane, ethylene, and ethane from ERCO₂. Conjugation with ZnO results in a sevenfold increase in specific activity of CuBDC MOF for ethylene evolution, along with a twofold decrease in its H₂ evolution activity. The exceptional electronic, mass transfer, and positive synergism among the different components in CuBDC/ZnO composite are demonstrated to endow it with excellent electrocatalytic performance (overall Faradaic efficiency (FE) of 77.5% for hydrocarbons, with FEC₁= 50.9% and FEC₂= 26.6%), lower Tafel slopes, enhanced exchange current density, appreciably low resistance to charge transfer, and electrochemical stability towards ERCO₂ (>14 h). The presented investigations suggest that the enhanced electronic conductivity, the open metal centers, the mixed valence states (Cu¹⁺ and Cu²⁺), and tandem catalytic sites (Cu and Zn) for asymmetric *CO adsorption, hydrogenation, and CO bond dissociation endow the CuBDC/ZnO with excellent activity toward ERCO₂ for production of hydrocarbons.

For the first time, a copper oxide (CuO)-containing lithium titanate (Li₄Ti₅O₁₂, LTO) is prepared via an air annealing approach in which copper oxalate (CuC₂O₄) and the commercial LTO are employed as the starting materials. As demonstrated by the X-ray diffractometer and X-ray photoelectron spectroscopy characterization results, CuO and LTO are indicated to be the main components of all prepared samples. Above all, all prepared samples, especially sample b, exhibit much better electrochemical performance than the commercial LTO. Particularly, the high-rate performances delivered by all synthesized samples, especially sample b, are significantly superior to that of the commercial LTO. For instance, the discharge capacity of sample b at 40 C after 500 cycles is about 40 mAh g⁻¹, which is about 14.8 times higher than that of the commercial LTO (2.7 mAh g⁻¹). In the full-cell test, the discharge capacity of the cell assembled by sample b and the modified lithium iron phosphate (LiFePO₄, LFP) at 10 C after 500 cycles (40.3 mAh g⁻¹) is significantly larger than that of the full-cell assembled by the commercial LTO and the modified LFP (0.1 mAh g⁻¹).

The green synthesis of perovskite quantum dots (PQDs) has garnered significant attention as a sustainable strategy to mitigate the environmental and safety concerns associated with conventional synthesis methods. This review systematically examines green and ecofriendly synthesis approaches for PQDs, with a particular focus on nontoxic green solvents. Based on their chemical properties and sources, these solvents can be categorized into three classes: polar solvents, bio-based solvents, and ionic liquids, each offering distinct advantages in terms of production yield, material stability, and optical performance. Notably, solvent polarity plays a crucial role in controlling the size distribution of PQDs, optimizing surface chemistry, and enhancing luminescence properties. Additionally, current challenges and future research directions in green synthesis are discussed, emphasizing the need for innovative solutions to improve process efficiency and scalability.

The present study explores innovative design principles for cationic lipid-basedgene delivery agents.It is demonstrated that cardanol, a blend of phenolic lipids with varying degrees of unsaturation, serves as an effective lipid moiety for cell transfection. A series of asymmetric, cardanol-based quaternary ammonium compounds (QACs) for gene delivery in K562 cell lines is synthesized. The resulting liposomes, characterized by their asymmetric tails, exhibit enhanced fusogenicity. Notably, lipids featuring cardanol as one tail and an aliphatic C12 or C14 chain as the second tail achieve higher transfection efficiency. The present study contributes to the development of key methodologies for optimizing transfection efficiency in K562 cell lines.

Submicron nanoparticles (NPs) of several semiconductors, such as Se or Te, exhibit pronounced dielectric Mie resonances in the visible range, which can be exploited for enhancing the efficiency of heterogeneous photocatalysis at the NP surface. Herein, it is demonstrated for the first time how dielectric Mie resonances in 190 nm amorphous a-Se NPs and a-Se/Ag₂Se hetero-NPs can enhance the efficiency of the model photocatalytic reactions involving organic (leuco-methylene blue) and inorganic (K₄[Fe(CN)₆]) redox-active species. Formation of the local enhanced electromagnetic field near a-Se NPs surface governs efficient photogeneration of e-h pairs either in a-Se core or Ag₂Se shell. The photoredox activity of a-Se NPs depends on many factors and can be altered via formation of the secondary semiconductor shell. Particularly, formation of several nm thick Ag₂Se shell on the surface of a-Se NPs increases photocatalytic activity governed by dielectric Mie resonances in a-Se/Ag₂Se core-shell NPs as compared to bare a-Se NPs. It is believed that submicron a-Se/M_xSe_y (M = Ag, Cu, etc.) core-shell NPs can be a promising platform for advanced semiconductor photocatalysts with enhanced activity in vis–NIR range and tunable redox properties.

This article explores the enhancement of piezocatalytic performance in barium titanate (BaTiO₃) through doping with iron (Fe) and copper (Cu). Density functional theory calculations using the Spanish Initiative for Electronic Simulations with Thousands of Atoms method are conducted to evaluate formation energies for interstitial and substitutional doping. In the interstitial case, a single Fe or Cu atom is inserted into a BaTiO₃ matrix of 135 molecules, while substitutional doping involved replacing barium (Ba) or titanium (Ti) atoms, yielding Ba₀.₉₇Fe₀.₀₃TiO₃, BaTi₀.₉₇Fe₀.₀₃O₃, and the corresponding Cu analogs. Results showed that substitution at the Ba site is energetically most favorable. Hydrothermal synthesis, followed by X-ray diffraction field emission scanning electron microscopy and X-ray photoelectron spectroscopy confirmed successful Fe and Cu incorporation predominantly at the Ba site. Piezocatalytic performance is assessed by Congo red dye degradation, where doped samples demonstrated superior activity compared to pure BaTiO₃ with Cu doping showing the highest efficiency. Scavenger experiments confirmed that degradation is mainly driven by piezocatalysis. The enhanced activity is attributed to increased charge carrier density and improved catalytic sites, highlighting the promise of Fe- and Cu-doped BaTiO₃ for environmental remediation applications.

Rice husk-derived biomass carbon holds strong potential in supercapacitor applications due to its sustainability and low cost. Herein, rice husk carbons are activated using KOH, NaOH, and their mixture, and their electrochemical properties are systematically evaluated. The NaOH-activated sample achieves the highest specific capacitance of 160.53 F g⁻¹ at 0.5 A g⁻¹, indicating superior charge storage ability. The mixed alkali-activated sample exhibits the best cycling stability, retaining 102.41% capacitance after 10000 cycles, along with the lowest internal resistance (0.05 Ω), reflecting excellent long-term performance and conductivity. The KOH-activated sample shows balanced behavior across (97.18% after 10000 cycles, 0.06 Ω, 154.12 F g⁻¹ at 0.5 A g⁻¹). These results suggest that the electrochemical performance is governed by the combined effects of multiple structural and chemical parameters rather than a single dominant factor. This comparative study highlights the distinctive advantages of each activation route and provides valuable insight for tailoring biomass carbon materials toward specific energy storage requirements. This study provides practical guidance for optimizing activation strategies to achieve high-performance, cost-effective supercapacitor electrodes from agricultural waste.

Water-soluble Bi₂O₃ and Bi₂S₃ quantum dots (QDs) are successfully synthesized using a novel, simple, and environmentally friendly one-pot method. X-ray diffraction and transmission electron microscopy analyses indicate that both Bi₂O₃ and Bi₂S₃ QDs are well-crystallized, with average diameter of 1.84 ± 0.02 and 2.96 ± 0.05 nm, respectively. The prepared QDs exhibit excellent fluorescence properties that remain stable over the long term. Notably, their fluorescence can be selectively quenched by Fe³⁺ with remarkable anti-interference capability. Furthermore, the fluorescence intensity demonstrates a strong linear correlation with the concentration of ferric ions across a wide range, facilitating effective detection of Fe³⁺. The mechanism underlying the fluorescence quenching by Fe³⁺ is primarily attributed to the overlap between the absorption spectrum of Fe³⁺ and either the excitation light or emission spectrum of Bi₂O₃ and Bi₂S₃ QDs. In addition, when compared to atomic absorption spectrophotometry and ultraviolet spectrophotometry for detecting Fe³⁺, the fluorescence method utilizing these prepared QDs offers enhanced operational efficiency and user-friendliness. This study not only broadens the application scope of bismuth oxide and bismuth sulfide in environmental monitoring but also provides significant insights for synthesizing water-soluble bismuth-based QDs.

Herein, the synthesis and catalytic performance of cobalt-based M–N–C materials are reported for the transfer hydrogenolysis of lignin-derived compounds. The Co-800 catalyst, comprising cobalt nanoparticles (CoNPs) and sub-nanometric Co(II) species embedded in a nitrogen-doped carbon matrix, demonstrates high activity and selectivity for CO bond cleavage in oxidized β-O-4 lignin model substrates using formic acid as a hydrogen donor. Subsequent acid treatment removes the CoNPs, yielding Co-800-AT, which retains significant catalytic activity, indicating that atomically dispersed cobalt species contribute to the observed reactivity. Both catalysts operate efficiently under mild conditions, with Co-800 maintaining high conversion and recyclability over multiple cycles. These findings underscore the promise of Co-based M–N–C systems as sustainable and robust catalysts for lignin depolymerization.

The current work shows how catalyst-free carbon nanospheres (CNS) can be produced utilizing straightforward one-step pyrolysis methods employing biowaste Caesalpinia sappan pods as a carbon precursor. The manufactured CNS with a particle size range of 40–50 nm that is obtained show a porous nature and contain more than 87% carbon. The synthesized CNS are used as potential antibacterial agents against E. coli and S. aureus by microscopic analysis. By observing the distorted cell envelopes of both E. coli and S. aureus compared with those of untreated cells, it is well understood that CNS, by binding to the outer envelope of cells, renders some changes in the peptidoglycan layer of both Gram-positive and Gram-negative microbes, which in turn restricts their further growth. This study confirms the first report of use of CNS as an effective antibacterial agent.