New Journal of Chemistry最新文献

Energy consumption remains a significant challenge in the removal of recalcitrant pollutants through advanced oxidation processes. In this study, a core–shell structural catalyst with graphitic carbon, encapsulating Fe₃C and Fe₃N (FeNC@C), was synthesized via pyrolysis for norfloxacin (NOR) degradation without extra energy. And we investigated several key parameters that influence the degradation of NOR, including H₂O₂ concentration, FeNC@C dosage, initial pH, and co-existing ions. The FeNC@C exhibits a degradation efficiency of 90% and total organic carbon removal exceeding 47% with 60 min. Our findings provide evidence that ˙OH is the primary reactive species in the process of NOR degradation. Additionally, we also propose a rational reaction mechanism and identify potential degradation intermediates. This study will facilitate further exploration of the heterogeneous catalyst as a potential approach for energy-efficient antibiotic decomposition.

The controlled growth of oriented hexagonal ZnO nanosheets (ZnONSs) on a nitinol (NiTi) fibre substrate without a seeding layer was presented by using ZnCl₂ as a precursor and KCl as a supporting electrolyte and a capping agent. The effect of the electrolytic composition and electrodeposition parameters on the morphology of ZnONSs was investigated. After annealing, novel porous ZnONSs (P-ZnONSs) were obtained and the overall morphology of oriented hexagonal ZnONSs was well maintained. The P-ZnONS coated NiTi (NiTi@P-ZnONS) fibre was used for solid-phase microextraction (SPME) coupled to HPLC-UV and showed good adsorption selectivity for polycyclic aromatic hydrocarbons (PAHs). As compared with that of the ZnONS coated NiTi (NiTi@ZnONS) fibre, the adsorption efficiency of the NiTi@P-ZnONS fiber was further improved. Moreover, the NiTi@P-ZnONS fibre showed superior adsorption capability for PAHs compared to typical commercially available 7-μm polydimethylsiloxane and 85-μm polyacrylate fibres. After the optimisation of SPME conditions with the NiTi@P-ZnONS fibre, good linearity was obtained in the range of 0.03–200 μg L⁻¹ (R² ≥ 0.9980) with low limits of detection (0.011–0.115 μg L⁻¹) and limits of quantification (0.037–0.383 μg L⁻¹). The intra-day and inter-day relative standard deviations (RSDs) of the proposed method with a single fibre ranged from 3.02% to 4.75% and 3.20% to 5.83%, respectively. Meanwhile, the proposed method was used for the selective preconcentration and determination of trace target PAHs in real water samples. Relative recoveries varied from 82.8% to 105% with RSDs from 3.34% to 8.58%. Additionally, this fibre presented good solvent resistance to perform a whole analytical process.

Metallacycles are structurally diverse molecular entities that have attracted significant research interest due to their potential applications in sensing, catalysis, and biomedicine. In this study, we report the synthesis of two discrete neutral Schiff base-derived dinuclear Cu(II) metallacycles [Cu₂L₂] (1) and [Cu₂L′₂] (2) achieved through coordination driven self-assembly using ligands N,N′-bis(3,5-di-tert-butylsalicylidene)-2,2′-diaminodiphenyl ether (H₂L) and (N,N′-bis(3,5-di-tert-butylsalicylidene)-hydrazine) (H₂L′), respectively. 1 and 2 are characterized by infrared, UV-vis, fluorescence, and electron paramagnetic resonance spectroscopy. The X-ray diffraction analysis confirms that 1 adopts a double helical structure while 2 exhibits a butterfly shape. The magnetic and electrochemical properties of metallacycles are investigated using superconducting quantum interference device (SQUID) magnetometry and cyclic voltammetry. The results revealed that the macrostructure of the metallacycles significantly influences their photophysical, magnetic and electronic properties. In addition, the catalytic efficiency of metallacycles towards ring-opening polymerization of ε-caprolactone is evaluated.

The excessive intake or deficiency of folic acid (FA), also known as vitamin B₉, can lead to several health problems. Therefore, significant research priority is required to develop facile analytical methods for FA detection. Herein, a V-shaped aggregation-induced emission (AIE) luminogen SDASA was introduced by condensing 4,4′-sulfonyldianiline with two equivalents of salicylaldehyde. The weakly fluorescent SDASA in DMSO showed yellow emission upon increasing the fractions of HEPES buffer (H₂O, 10 mM, pH 7.4) from 80% to 95% because of the combined effects of AIE and ESIPT. The formation of self-aggregates of SDASA was supported by SEM and DLS analyses. AIEgen SDASA (f_HEPES 95%) was employed as probe 1 for FA detection. The fluorescence emission of AIEgen SDASA (λ_em = 550 nm, λ_ex = 390 nm) was blue-shifted and enhanced at 475 nm by FA. The results of DFT, fluorescence lifetime, zeta potential, DLS, and UV-vis absorption studies revealed that the interaction that occurred between FA and SDASA inhibited the intramolecular charge transfer and aggregate morphology of SDASA. With probe 1, the FA concentration can be detected down to 0.83 μM. Further studies with SDASA in DMSO showed strong green emission at 525 nm upon complexation with Zn²⁺ ions. The in situ generated SDASA–Zn²⁺ complex was used as probe 2 for the fluorescent turn-off detection of hemoglobin and glucose with a detection limit of 0.57 nM and 0.32 μM, respectively. Finally, the analytical utility of the developed probes was examined by detecting selective analytes in real blood serum.

Selectivity control of aniline oxidation and low reactant conversion in traditional synthesis methods are great challenges, and it is desirable to develop a green, low-cost and highly efficient catalytic route toward value-added products. Herein, an Rb-promoted Fe/CeO₂ nanocatalyst was prepared to understand the effects of Rb-promoter on the catalytic performance for the selective oxidation of aniline to azoxybenzene using H₂O₂ as an oxidant. The 0.1 M Rb-4% Fe/CeO₂ (Rb–Fe/CeO₂) catalyst showed a high aniline conversion of 100% with 91% selectivity of azoxybenzene. This is because the existence of Rb contributes to the electron transportation property, decreases activation energy and leads to lattice distortion of Fe/CeO₂ and further formation of oxygen vacancies and Ce³⁺, which contributes to improving the activity of Fe/CeO₂ nanocatalysts for aniline conversion reaction. The Rb used to modify Fe/CeO₂ nanocatalysts can not only passivate the strong Brønsted acid sites and stability of Fe/CeO₂ but also enhance the Fe dispersion and induce an electron-rich chemical environment for the supported Fe species and promote the activation of the substrate. All these effects lead to the desirable catalytic performance. The increased basic strength of the cation-promoted catalyst improves the electron density of the active Fe species, resulting in a higher yield of the desired aromatic azo compounds. This compensates for electronic deficiencies in the Fe, enhancing its catalytic activity without interference. Experiments were conducted as a function of catalyst loading (20–100 mg), time (2–24 h), temperature (25–100 °C), types of solvent and solvent amount (0.5–2 ml) in 50 ml round bottom flask with reflux condenser. Our work proposes a facile approach to develop and promote non-noble metal catalysts for the effective conversion of aniline into azoxybenzene under mild reaction conditions.

Here, we synthesized three covalent organic polymers (COPs) with varying π–π conjugation and coordination numbers. COP-H3, as a luminesent probe, exhibited a highly selective sensing of OH-containing nitro-explosives, while COP-H2 exhibited high selectivity for trinitrophenol and 2,6-DNP. Their sensing behavior could be well explained by the absorption competition quenching mechanism.

The lifetime of organic solar cells (OSCs) remains a significant challenge for their commercial viability. In this study, we successfully synthesized a low band gap copolymer, P3T-IID, with an energy gap (E_g) of 1.61 eV, and HOMO and LUMO levels of −5.43 eV and −3.78 eV, respectively, using direct heteroarylation polycondensation (DAP) copolymerization of a terthiophene donor moiety with an isoindigo acceptor moiety. We investigate the stability of pristine P3T-IID copolymer films under conditions of 75% relative humidity, UV light illumination, and an elevated temperature of 85 °C for over 50 h. The results reveal significant absorbance loss due to UV-irradiation-induced processes, such as chain scission and chemical reactions involving free radicals, while the polymer integrity remains largely unaffected by high humidity and elevated temperatures. Interestingly, the copolymer demonstrates excellent thermal stability with a high decomposition temperature of 390 °C. Thermal stability studies on inverted OSCs fabricated with a 1 : 4 ratio of P3T-IID : PC₇₀BM show that the devices retained over 40% of their initial power conversion efficiency (PCE) after 24 h of annealing at 85 °C. Further investigation into the degradation mechanism reveals that the PCE loss is primarily due to the deteriorated morphology of the P3T-IID:PC₇₀BM active layer and the formation of an unwanted interlayer between the active layer and the electrodes.

Diffusion dialysis (DD) with anion exchange membranes (AEMs) as the core component is an ideal technology for acid recovery from acidic wastewater. Herein, a series of TEA–BPPO AEMs were prepared from triethanolamine (TEA) and brominated polyphenylene ether (BPPO) using the solution casting method. The structures of the prepared membranes were characterized and analyzed through nuclear magnetic resonance hydrogen spectroscopy (¹H NMR), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). In addition, the properties of the membranes, such as ion exchange capacity (IEC), linear swelling rate (LSR), water uptake (W_U), chemical stability, thermal stability and mechanical stability, were explored. In DD experiments, the optimal AEM (i.e., TEA–BPPO–M80) applied to simulate acid recovery from a mixed HCl (1 mol L⁻¹)/FeCl₂ (0.2 mol L⁻¹) solution exhibited an acid dialysis coefficient (U_H⁺) of 0.0629 m h⁻¹ and separation factor (S) of 97.78, which were significantly better than those of the commercial membrane DF-120. In addition, the TEA–BPPO–M80 AEM exhibited excellent thermal stability and acid resistance. In summary, the prepared membranes possess great potential for application in DD acid recovery.

The development of earth-abundant, highly active, and long-term durable electrocatalysts is crucial for advancing the practical applications of biofuel cells (BFCs). Herein, we demonstrate heterostructured three-dimensional (3D) iron-cobalt phosphide nanosheets on nickel oxide nanoparticles (3D FeCoP NS|NiO NP) for enhanced glucose oxidation reaction (GOR) under an alkaline electrolyte. The 3D FeCoP NS|NiO NP heterostructured electrodes are developed using a chemical etching approach followed by an electrochemical deposition strategy. The 3D FeCoP NS|NiO NP heterostructures deliver a higher catalytic anodic current density (∼10.34 mA cm⁻²) with a less positive potential (∼0.22 V (vs. Ag/AgCl)), greater mass activity (∼16.0 A g⁻¹), high double layer capacitance (∼0.88 mF cm⁻²), high electrochemically active surface area (ECSA) (∼22.12 cm⁻²), highest sensitivity (13.97 mA cm⁻²) and long-term durability (100 h). The 3D nanosheet-like surface morphology, less agglomerated structure, high ECSA, and synergistic effect of Fe and Co are responsible for the enhanced electrocatalytic GOR activity of the 3D FeCoP NS|NiO NP heterostructures. Addressing the cost-effectiveness of the 3D FeCoP NS|NiO NP heterostructures while maintaining high performance is necessary to make potential biofuel cells. Furthermore, ensuring the long-term stability of the 3D FeCoP NS|NiO NP heterostructures will guarantee reliable and sustained operation in real-world applications.