New Journal of Chemistry最新文献

ZIF-8, a metal–organic framework that has significant benefits such as a substantial specific surface area, abundant active sites, and high porosity, has extensive application in environmental remediation. However, ZIF-8 is powdery and easily agglomerated, making it difficult to separate ZIF-8 from aqueous solutions and thus limiting its practical application in wastewater treatment. In this work, sodium alginate was chosen as a gel matrix, and CaCl₂ as a cross-linking agent to form a calcium cross-linked MOF gel material (ZIF-8/SA). The batch adsorption investigations demonstrated that the saturated adsorption capacities of ZIF-8/SA in single Mn²⁺ pollution solution and Mn–Cu–Cd composite pollution solution are 179.86 mg g⁻¹ and 101.86 mg g⁻¹, respectively. Specifically, the adsorption of Mn²⁺ followed the Langmuir model and exhibited monomolecular layer adsorption. Furthermore, the adsorption of Cu²⁺ and Cd²⁺ followed the quasi-first-order kinetic model, which is primarily physical adsorption. The adsorption order of ZIF-8/SA for contaminants in the adsorption process is as follows: Cu²⁺ > Cd²⁺ > Mn²⁺. The SEM-EDS, FT-IR, and XPS studies revealed that the adsorption mechanism of ZIF-8/SA mostly involves ion exchange, coordination of carboxyl/hydroxyl/amino groups, and electrostatic attraction. To summarize, the experimental findings of this study demonstrate that the synthetic ZIF-8/SA hydrogel has promising applications for practical pollution treatment.

A layered nanoelectrode design was based on the high surface area of graphene oxide and reduced graphene oxide; these layers were decorated with n/p-type palladium oxide nanoparticles (NPs) and cadmium sulfide NPs. The building of electron transfer through n/p-type eases the movement of electrons and increases electron clouds for the supercapacitor efficiency of fabricated nanoelectrodes, and their electrochemical characteristics were investigated using electrochemical impedance spectroscopy (EIS) data. Applications as supercapacitors and other energy storage devices were supported by the construction, development, and surface modification of electron transport that was measured by EIS. The values of capacitance detected for GO@PdO@rGO (16.4 μF cm⁻²) and GO@PdO@rGO.CdS (21 μF cm⁻²) refer to the improvement in the electron transfer by the unique electrode. At 100 cycles, the capacitance retention of the nanoelectrodes was measured via a cyclovoltammetry device to reveal the high stability of GO@PdO@rGO (96%) and GO@PdO@rGO.CdS (97%) compared to the other electrode. The electroactive mass was determined to be 0.3396 mF cm⁻² for GO@PdO@rGO and 0.426 mF cm⁻² for GO@PdO@rGO.CdS; the electrochemical surface area (ECSA) was calculated to be 1007.8 for GO@PdO@rGO and 3058.5 for GO@PdO@rGO.CdS. The study suggests that these novel fabricated nanoelectrodes provide high efficiency for supercapacitors, batteries, water desalination, and energy storage, so they are promising candidate nanoelectrodes for energy applications.

Highly efficient three-dimensional (3D) lead-free halide perovskites that produce blue light emission with outstanding stability have attracted global research attention. In order to increase the light emission efficiency of Rb₂LiBiBr₆ perovskites, band structure engineering can be performed by doping Cu²⁺ ions. In this work, the structural, chemical and optical characteristics of pure Rb₂LiBiBr₆ (RLBB) and Cu²⁺-doped Rb₂LiBiBr₆ (RLBBC) phosphors produced through conventional wet chemical processes are reported. A narrow and comparatively unique blue emission was exhibited by Cu²⁺-doped Rb₂LiBiBr₆ double perovskites (DPs) as a result of electron–phonon interactions. The phase purity and microstructure of the Rb₂LiBiBr₆:Cu²⁺ DP were assessed using X-ray diffraction and scanning electron microscopy, respectively. All the synthesized samples showed a orthorhombic crystal structure, and B sites had a substantial impact on the Pnma space group in the Rb₂LiBiBr₆ DP framework. The Bi³⁺ ions at the B′ sites were replaced by the doped Cu²⁺ ions, which distributed themselves to an equilibrium valence state and showed minimal variation in the ionic radius. Photoluminescence (PL) spectra were used to explore the corresponding mechanism of the Cu²⁺ → Bi³⁺ energy-transfer process. The Cu²⁺-doped Rb₂LiBiBr₆ (RLBBC) phosphors exhibited a blue emission at 469 nm when excited at 367 nm. It showed an optical bandgap of 2.87 eV at room temperature. This as-prepared perovskite showed outstanding stable chromaticity with (x,y) coordinate values of (0.1367, 0.0596) under a continuous irradiation of 367 nm UV light. This lead-free and highly effective Cu²⁺-Rb₂LiBiBr₆ DP has a wide range of applications in the rarest blue photonic and optoelectronic domains as it demonstrates the potential to overcome the obstacles of extreme toxicity and inadequate stability.

Herein, β-PbF₂:Eu³⁺/K⁺ glass ceramics (GCs) were synthesized and characterized by X-ray diffraction (XRD), photoluminescence (PL) and decay curves. Based on the XRD analysis, it was inferred that Eu³⁺ and K⁺ ions were doped in the β-PbF₂ lattice by substituting Pb²⁺ ions. Compared with the interstitial fluorine (F_i⁻) (Eu³⁺ + F_i⁻ = Pb²⁺), K⁺ substitutional doping (Eu³⁺ + K⁺ = 2Pb²⁺) was the preferential charge-compensating mechanism with the introduction of K⁺ ions in the β-PbF₂:Eu³⁺ GCs. Consequently, this is the first report on the anomalous emission of the ⁵D₀/⁷F₄ transition in β-PbF₂:Eu³⁺ GCs. Based on this anomalous ⁵D₀/⁷F₄ transition, a new lattice site with D_4d symmetry occupied by Eu³⁺ ions was proposed for the first time in β-PbF₂:Eu³⁺ GCs. Moreover, according to the intensity ratio of I(⁵D₀/⁷F₀)/I(⁵D₀/⁷F₂) (I₀₀/I₀₂), I(⁵D₀/⁷F₂)/I(⁵D₀/⁷F₁) (I₀₂/I₀₁) and I(⁵D₀/⁷F₄)/I(⁵D₀/⁷F₁) (I₀₄/I₀₁), the breaking of the local lattice symmetry around the Eu³⁺ ions induced by K⁺ ions was demonstrated in detail. With the introduction of K⁺ ions in β-PbF₂:Eu³⁺ G

Photodynamic therapy (PDT) is a minimally invasive treatment that shows promise in replacing traditional surgery, chemotherapy, and radiotherapy. In this study, 15 NO-type porphyrin ferulic acid derivatives were synthesized using acyl chlorination, substitution, and complexation with metal salts. After 10 s of light irradiation, the NO-type porphyrin–ferulic acid derivatives could effectively quench DPBF, among which compounds 6a–6e and compounds 7a–7e reduce the fluorescence intensity of DPBF to below 30, indicating that they have a good ability to produce singlet oxygen. Additionally, NO-type porphyrin–ferulic acid derivatives rapidly released NO in 5 min and substantially increased its level within 60 min. The anti-tumour activity experiments showed that NO porphyrin ferulic acid derivatives could produce different degrees of phototoxicity toward A549 cells and HepG2 cells under light conditions. The compounds with shorter alkyl chains showed better antitumor activity, while the elongation of alkyl chains reduced the activity of the compounds. Among these compounds, compound 7a showed optimal inhibition (IC₅₀ = 43.82 ± 2.50) and had the potential to be a combination therapeutic agent for photodynamic therapy and chemotherapy.

The photocatalytic conversion of endless solar energy into storable and usable chemical energy, such as photocatalytic hydrogen peroxide production, is promising and attractive. However, a satisfactory hydrogen peroxide yield has not been achieved using photocatalysts due to the rapid recombination of photoexcited carriers and the rapid decomposition of H₂O₂. Herein, a polymer polyethyleneimine (PEI)-assisted Pd metal loading BiOCl nanosheet photocatalyst (Pd/PEI/BOC) is designed to achieve higher photocatalytic activity. Experimental results show that compared to the Pd/BOC catalyst with a Pd loading of only 0.26 wt%, the Pd/PEI/BOC catalyst can achieve a higher Pd loading of 0.45 wt%, which is due to the obvious shifting of the isoelectric point (IEP) of BiOCl from the pH value of 4.1 to 8.4 in the presence of PEI, leading to enhanced immobilization. Furthermore, H₂O₂ decomposed more slowly for the Pd/BOC catalyst modified by PEI. In addition, Pd can significantly enhance the separation of electrons–holes and light absorption range, especially for visible light. Therefore, under simulated sunlight, this Pd/PEI/BOC catalyst displayed a higher H₂O₂ production ability of 3700.23 μmol g⁻¹ h⁻¹.

Ga₂O₃/MCM-41-x (x = 0.4, 0.5, 0.6) heterogeneous catalysts, each with varying levels of Br doping, were synthesized using mesoporous molecular sieves (MCM-41) as a carrier and employed in the synthesis of propylene carbonate (PC) from propylene oxide (PO) and carbon dioxide (CO₂). The reaction was conducted under solvent-free and additive-free conditions. Various techniques were utilized to characterize the catalysts’ chemical composition, morphology, and structure. The effects of varied reaction conditions on PO conversion and PC selectivity using Ga₂O₃/MCM-41-0.5 catalysts were investigated. Under the reaction conditions of 120 °C, 3.5 MPa, 10 h and catalyst dosage of 2.6 wt%, the PO conversion and PC selectivity reached 99.7% and 99.1%, respectively. The catalytic impact correlates strongly with the doping amounts of Ga₂O₃ and Br, primarily due to the interaction of Ga₂O₃ with the surface of MCM-41, leading to the generation of more basic sites and, consequently, a greater abundance of alkali centers. As a nucleophilic reagent, Br functions synergistically with Ga₂O₃/MCM-41, augmenting the ring-opening rate of PO and improving the activation ability of CO₂. The stability of the catalyst underwent evaluation, revealing a slight decrease in activity after repeated use. The reaction mechanism underlying PC synthesis catalyzed by Ga₂O₃/MCM-41-0.5 was speculated.

A ZIF-derived carbon framework offered abundant platforms for the rational design and construction of high-performance nonprecious-metal catalysts. In this study, a Co-coordinated ZIF-derived carbon framework was synthesized by substituting Co for Zn in ZIF-8, followed by pyrolysis. The resultant Co–Zn@C–N, wrapped by carbon nanotubes (CNTs), exhibited superior catalytic performance in the selective oxidation of benzyl alcohol (BnOH), achieving an optimal BnOH conversion of 92% and a benzaldehyde (BzH) selectivity of 92% at room temperature. Characterization results confirmed that the reaction proceeded through a free-radical mechanism, and the CNTs, formed through catalytic graphitization induced by Co nanoparticles, provided solid–liquid reaction interfaces and enhanced the electron transfer between radicals and skeletons. The Co and Zn species, acting as the primary active sites, exhibited a synergistic effect that enabled the good performance of the Co–Zn@N–C catalyst. Moreover, the elevated graphitic degree, substantial content of Co⁰ and graphitic N collectively contributed to the enhanced catalytic performance. Additionally, the catalyst had excellent reusability and stability, manifesting negligible variations in activity across four consecutive experimental cycles. This Co–Zn@N–C catalyst system provides a promising foundation towards the design of highly active non-noble catalysts for organics oxidation reactions under mild conditions.

The utilization of resins combined with nanoparticles represents the prevailing method for fabricating superhydrophobic fabrics. Nevertheless, a notable drawback in this approach has been the limited durability of these fabrics, constraining their practical applications. In our ground-breaking study, we introduce an innovative and reliable solution to address this durability issue. We demonstrate, for the first time, that biopolymer resins offer a significantly enhanced level of durability to superhydrophobic fabrics when compared to their synthetic counterparts, whether organic or inorganic. Our proposed method employs the dip-coating technique, enabling us to create fabrics capable of maintaining their anti-wetting properties even in the face of mechanical stress. The deposition of this coating on the fabric surface elevates the water contact angle to an impressive 157°, with a sliding angle measuring below 10°. In terms of oils, the fabric surface exhibits superoleophilic behavior, with a contact angle of 0°. Furthermore, our coating exhibits outstanding thermal stability, enduring temperatures of up to 250 °C, while also demonstrating UV resistance for up to 50 hours without any loss of superhydrophobicity. Mechanical stability was also assessed, and the coating proved resilient against abrasion until the appearance of tears on the fabric, without compromising its superhydrophobic properties. Our coated fabric has been effectively employed in separating oil/water mixtures, achieving an exceptional separation efficiency of 99%, a performance that remains consistent across multiple cycles. We envision that these superhydrophobic/superoleophilic fabrics, characterized by their cost-effectiveness, eco-friendliness, remarkable durability, and ease of industrial scale application, hold immense potential for applications in clothing manufacturing and water/oil separation.

Rechargeable zinc–air batteries have been extensively studied as a potential solution for overcoming the challenges of energy crises and achieving sustainable development. The primary bottleneck of zinc–air batteries is the lack of efficient and low-cost dual-functional catalysts. In this study, we successfully prepared carbon nanotube-encapsulated bimetallic Co/Cu (Co/Cu_0.2@NC) catalysts that exhibit excellent ORR (E_1/2 = 0.838 V) and OER (overpotential of 322 mV at 10 mA cm⁻²) performances, exceeding those of the commercial RuO₂ and Pt/C catalysts. Furthermore, rechargeable liquid zinc–air batteries prepared using the Co/Cu_0.2@NC catalysts show a high power density (171.44 mW cm⁻²), a high open circuit voltage (1.485 V), and a long life with stability for 2400 cycles (or 400 h). More importantly, flexible zinc–air batteries prepared using this catalyst exhibit a peak power density of 70.8 mW cm⁻² and a superior stability for 480 cycles (or 80 h). This excellent dual-functional catalyst has great potential for zinc–air battery and other energy storage applications.