New Journal of Chemistry最新文献

The electrochemical conversion of CO₂ to valuable hydrocarbons, particularly methane (CH₄), presents a promising approach for combating climate change; however, it remains challenged by competing side reactions and complex multi-electron transfer mechanisms. This study presents a novel catalyst comprising carbon nanofiber-supported amorphous CuSiO₃ (CuSiO₃/CNFs), which demonstrates significantly enhanced CH₄ selectivity. Compared to pure CuSiO₃, the CH₄ selectivity of CuSiO₃/CNFs is increased by up to 1.9 times, achieving a FE_CH4 of 67.8% at −1.6 V (vs. RHE). Remarkably, after 10 h of sustained operation at 100 mA cm⁻² within a flow cell, the FE_CH4 remains above 50%. Characterization through CO₂-TPD and ATR-FTIR reveals that the enhanced performance is attributed to the formation of stable and well-dispersed Cu–O–Si active sites in situ on the CNF surface and the optimized reaction interface that promotes H₂O and CO₂ adsorption and activation. This study offers critical insights into structural regulation strategies for designing effective catalysts for CO₂ reduction, paving the way for advancements in sustainable hydrocarbon production.

Lanthanum vanadate (LaVO₄) nanoparticles and PANI–LaVO₄ nanocomposites with varying LaVO₄ loadings (2, 4 and 6 wt%) were synthesized and systematically investigated for supercapacitor applications. XRD confirmed the monoclinic crystal structure of LaVO₄, while FESEM and EDX analyses revealed uniform incorporation of nanoparticles within the PANI matrix. Electrochemical characterization demonstrated that the PANI–LaVO₄ 2 wt% nanocomposite exhibited superior capacitive performance, delivering a high specific capacitance of 1013 F g⁻¹ at 2 A g⁻¹ with excellent cycling stability (>95% retention after 2000 cycles). To harness this performance, an asymmetric supercapacitor device (ASC) was fabricated using PANI–LaVO₄ (2 wt%) as the positive electrode and activated carbon (AC) as the negative electrode, achieving a specific capacitance of 546 F g⁻¹ at 1 A g⁻¹. The device exhibited outstanding stability with 90% capacitive retention after 2000 cycles, alongside an energy density of 75 Wh kg⁻¹ and a maximum power density of 8.3 kW kg⁻¹. These findings highlight the promising potential of PANI–LaVO₄ nanocomposites, particularly at optimized loading for superior electrochemical storage technologies.

The densities of magnesium sulfate (MgSO₄) solutions in water, ethanol, and water–ethanol mixtures, and the respective solvents, were determined by RD bottle at temperatures of 303.15–323.15 K. The density of the solvents increased with the addition of MgSO₄, while a temperature rise had a decreasing effect. The densities of the solvents and solutions were utilized for evaluating the apparent molar volume (V_ϕ) of MgSO₄ solutions. The V_ϕ decreased with increasing concentration of MgSO₄, whereas it increased with a change in solvent from pure water to ethanol and with a temperature rise. Limiting apparent molar volume (V^o_ϕ) was evaluated by Masson's and Redlich, Rosenfeld, and Meyer's (RRM) equations. V^o_ϕ was split into its ionic components, to evaluate the ionic contributions. The structure-making/breaking nature of MgSO₄ was characterized by Hepler's constant (δ²V^o_ϕ/δT²)_P. Hepler's constant is negative, confirming the structure-breaking conduct of MgSO₄, which is very well supported by the positive values of limiting apparent molar volume of transfer (Δ_tV^o_ϕ) and trends of thermodynamic parameters.

Amidated collagen (A-COL) with good biocompatibility was synthesized via carbodiimide-mediated coupling of L-arginine to native collagen (COL). The structure and charge type of A-COL and COL were characterized by FTIR, zeta potential analysis and elemental analysis (EA). A-COL was incorporated into the foam detergent as both an antibacterial agent and foam stabilizer. The antibacterial activities of A-COL against E. coli and S. aureus were analyzed, along with its impact on, and mechanism for enhancing, the detergent's foaming capacity and foam stability. The results showed that A-COL inhibited both bacteria, with MIC values of 0.312 mg mL⁻¹ and 0.078 mg mL⁻¹, respectively. The antimicrobial mechanism of A-COL involves its positively charged and synergistically active structure, which enhances electrostatic interactions and destroys the cell's integrity. Foam stability with A-COL was 1.43-fold higher than without A-COL. The addition of A-COL enhances the foam stability of the foam detergent through its long-chain molecules forming an interweaving network structure. The detergent containing A-COL exhibited no skin irritation, excellent biocompatibility, and a predicted shelf life of over 3 years as determined by accelerated thermal stability testing. The dual-functional A-COL significantly enhances the detergent's antibacterial efficacy, storage stability, foam-stabilizing capacity, and biocompatibility, demonstrating considerable potential for application in biomass-based detergents.

Molybdenum dioxide has emerged as a promising anode material for lithium-ion batteries (LIBs), owing to its distinct advantages of high theoretical specific capacity, efficient charge transfer kinetics, and multivalent oxidation states. Its layered crystal structure facilitates rapid Li⁺ diffusion, while its multielectron transfer mechanism enables enhanced energy storage density, positioning it as a competitive alternative to conventional graphite anodes. We achieve the layered structure by synthesizing amorphous molybdenum dioxide (MoO_2−x) through a solution-based approach combined with low-temperature annealing. This tackles the critical challenges of structural degradation and restricted conductivity commonly encountered in transition metal oxide anodes. The non-crystalline structure of the as-prepared material induces reconfigured atomic arrangements, leading to a marked improvement in electronic conductivity and an enhancement in the kinetic response of Li⁺ insertion/extraction reactions during extended charge–discharge cycles. Electrochemical tests demonstrate that the optimized amorphous MoO_2−x anode demonstrates an exceptional reversible discharge capacity of 817.1 mAh g⁻¹ at a current density of 0.1 A g⁻¹. Moreover, the material exhibits exceptional cycling durability, retaining a capacity of 436.3 mAh g⁻¹ even after 500 charge–discharge cycles at an elevated current density of 5.0 A g⁻¹. Empirical evidence demonstrates that amorphous phase engineering significantly enhances both the structural integrity and cycling stability of MoO_2−x, facilitating its real-world implementation as a superior anode material in next-generation lithium-ion battery systems. This observation highlights the potential of non-crystalline design strategies as a systematic approach for optimizing transition metal oxide-based anodes for advanced energy storage technologies.

This article presents the results of experimental and theoretical studies on the physico-chemical properties of metal–organic compounds, using silver clusters and the drug “methotrexate”. The thermodynamic parameters for adsorption and the energy levels of the orbitals for several models of these compounds were calculated to better understand the features of their adsorption on metal clusters. It was found that the adsorption of methotrexate onto the surface of nanoparticles occurs through the carboxyl groups on the molecule. A specific Raman band corresponding to adsorption was revealed at 1586 cm⁻¹ and confirmed with DFT calculations. Analyses using critical point calculations, quantum theory of atoms in molecules (QTAIM), indices of conceptual density functional theory (CDFT), visualization of electron localization function (ELF), localized orbital locator (LOL), non-covalent interaction (NCI), interaction region indicator (IRI) isosurfaces, and RDG graphs were also carried out for metal–organic complexes. The possibility of charge transfer from the cluster to the molecule is demonstrated when the complex is excited at a wavelength of 532 nm and the calculated energy parameter is 2.33 eV. The obtained results clarify the issues of surface chemistry during the design of SERS sensors based on silver nanoparticles and highlight the critical spectral shifts for the registration of the drug “methotrexate”.

The present study investigates the corrosion inhibition performance of a Cu–metal–organic framework (Cu–MOF) functionalized with bay leaf-derived carbon dots (MOF@CDs) for Q235B steel in 1 M HCl solution. The electrochemical tests (open circuit potential, potentiodynamic polarization curves, and electrochemical impedance spectroscopy) results demonstrated that the MOF@CDs could effectively inhibit steel corrosion, characterized by shifting the corrosion potential in the negative direction and decreasing the corrosion current density with the increase of the inhibitor concentration. The MOF@CDs function as an effective mixed-type corrosion inhibitor, primarily suppressing the anodic dissolution process while also hindering cathodic hydrogen evolution. Surface characterization using Fourier transform infrared spectroscopy (FTIR) confirmed the adsorption of MOF@CDs onto the steel surface through interactions involving hydroxyl, carboxyl, and aromatic groups. UV-vis spectroscopy further confirmed the adsorption behavior of MOF@CDs on the steel surface by suggesting the complexation between the metal and inhibitor. The presence of bay leaf-derived CD components in the MOF structure enhanced its corrosion inhibition capability, as the polyphenolic and oxygen-rich constituents facilitated strong surface interactions. Additionally, atomic force microscopy (AFM) demonstrated a substantial reduction in surface roughness after inhibitor adsorption, highlighting the protective barrier formation.

In recent years, vacuum ultraviolet (VUV) radiation has garnered significant attention for its capacity to photodissociate organic compounds and reduce transition metals. However, the exploration of VUV-based Cu(II)/PMS systems has been notably absent. This study explores the efficiency and influencing factors of sulfamethazine (SMZ) degradation utilizing a VUV/Cu(II)/PMS approach. Firstly, the removal efficiencies of different systems were compared. VUV demonstrated significantly superior removal capability to UVC, owing to excellent photolytic capability. Secondly, SMZ degradation in the VUV/Cu(II)/PMS system showed pH independence, minimal anion effects, but high susceptibility to concentrated organic matter. The electron spin resonance (ESR) and quenching experiments indicate that hydroxyl radicals (˙OH) and sulphate radicals (SO₄˙⁻) play a significant role in the degradation mechanism of SMZ, in the presence of Cu(II) reducing the contribution of SO₄˙⁻. Furthermore, quantitative experiments on Cu(I) across different systems demonstrate that VUV exhibits superior reducing power. Finally, degradation products were detected using LC-MS, and four degradation pathways were thereby proposed including Smiles rearrangement, nitration, and breaking of the S–N bond and the C–N bond.

Compared to single-function inhibitors, the novel multifunctional corrosion inhibitor developed in this study—oleic acid polyethylene glycol ester phosphate (OPP400)—achieves synergistic corrosion inhibition through molecular engineering that integrates multiple active functional segments. Its corrosion inhibition behavior and mechanism on Mg and Mg alloy in 3.5 wt% NaCl solutions were systematically investigated. The corrosion inhibition performance of OPP400 was evaluated using a combination of EIS, PDP, SEM, AFM, and contact angle measurements. The results demonstrate that at the optimal concentration of 100 mg L⁻¹, OPP400 achieves corrosion inhibition efficiencies of 89.07% for pure Mg and 79.55% for Mg alloy. The PDP curves reveal OPP400 to be a mixed-type corrosion inhibitor. EIS reveals a marked increase in charge transfer resistance and a marked decrease in double-layer capacitance, which indicates the formation of a dense adsorbed film on the metal surface. Mott–Schottky analysis further corroborates that OPP400 selectively blocks Cl⁻ ions by reducing the carrier density in the oxide film and enhancing the energy barrier of the passivation film. Surface analysis reveals that OPP400 significantly reduces the surface roughness of the substrate and enhances its hydrophobicity, thereby increasing the water contact angle from 37° to more than 66°. The inhibition mechanism is attributed to the synergistic effects of chemical adsorption, hydrophobic layer formation, and ionic barrier action, which collectively block the penetration of corrosive species (e.g., Cl⁻ and H₃O⁺). This study offers critical theoretical basis and practical guidance for the molecular design of corrosion inhibitors targeting Mg and Mg alloy.

In this work, a novel polydopamine (PDA)-decorated CoMoO₄ (PDA@CoMoO₄) composite was fabricated and employed to catalyze peroxymonosulfate (PMS) towards tetracycline hydrochloride (TCH) decomposition from aqueous solutions. It was discovered that the PDA@CoMoO₄ exhibited excellent performance and enhanced TCH decomposition. The results revealed that the system with a catalyst dosage of 80 mg L⁻¹ and a PMS dosage of 1.0 mM could decompose 98.0% of 15 mg L⁻¹ TCH after 50 min. Electron paramagnetic resonance (EPR) analyses and reactive oxygen species (ROS) capture tests verified that multiple ROS, including singlet oxygen (¹O₂), superoxide anions (O₂˙⁻), sulfate radicals (SO₄˙⁻), and hydroxyl radicals (˙OH), were involved in TCH decomposition. A potential catalytic mechanism of PDA@CoMoO₄ catalyzed PMS was proposed, mainly involving the promotion of Mo⁶⁺/Mo⁴⁺ and Co³⁺/Co²⁺ redox cycles by electrons provided by PDA, and the synergistic effect of Mo⁶⁺/Mo⁴⁺ and Co³⁺/Co²⁺ redox cycles in catalyzing PMS. Following four consecutive cycles, the TCH elimination efficiency remained above 87%, suggesting that the PDA@CoMoO₄ composite has good reusability. In short, the PDA@CoMoO₄ composite is a good candidate material for wastewater treatment.