New Journal of Chemistry最新文献

Developing efficient, metal-free electrocatalysts for the oxygen reduction reaction (ORR) is essential for advancing sustainable energy technologies. In this work, we report the synthesis of nitrogen-doped (N–GS) and phosphorus-doped (P–GS) graphene spherical shells as high-performance, non-metallic ORR catalysts. N–GS was directly synthesized via chemical vapor deposition using acetonitrile as a dual carbon and nitrogen source, while P–GS was prepared through post-phosphorylation of undoped graphene shells. Elemental analysis confirmed nitrogen and phosphorus doping levels of 8.59 at% and 2.80 at%, respectively. The three-dimensional spherical architecture effectively prevents graphene sheet aggregation and increases accessible surface area. Heteroatom doping introduces lattice distortions and defect sites, which enhance ORR activity. Both N–GS and P–GS exhibited half-wave potentials close to that of commercial Pt/C (0.82 V), and superior kinetics with Tafel slopes of 70 and 75 mV dec⁻¹, respectively. Electrochemical impedance spectroscopy revealed low charge transfer resistance, and Koutecky–Levich analysis confirmed a four-electron ORR pathway for both materials. These results demonstrate that heteroatom-doped graphene shells are promising metal-free catalysts for ORR, offering a cost-effective alternative to precious metal-based catalysts in fuel cell applications.

The concentrated sulfuric acid leachate of laterite nickel ore was treated with ascorbic acid as the leaching agent to regulate the valence states of metals. Ascorbic acid treatment was combined with component separation and a regulatory strategy to prepare a multi-metallic spinel-structured lithium-ion battery anode, G-FNMMA, directly. The anode material consisted of multiple spinel phases, as represented by (Fe, Ni, Mn, Mg, and Al)O₄. It had a stable microspherical structure with a gradient architecture. Characterization by XRD, SEM, TEM, and XPS indicated that this structure and crystal defects of the anode material favored electrochemical activity. Electrochemical tests proved that upon the first discharge, the specific capacity of the optimal sample G-FNMMA[Fe5] reached 1121.2 mAh g⁻¹. The material still maintained a reversible capacity of 740.2 mAh g⁻¹ after 500 cycles at a current density of 1000 mA g⁻¹, indicating excellent cycling stability and rate performance. The anode's exceptional performance was mainly attributed to the high stability of the spinel structure and the dominance of pseudo-capacitive lithium-ion storage. The direct transformation of laterite nickel ore into a high-performance lithium-ion battery anode was studied in detail to substantiate a new, feasible pathway for the high-value, green utilization of laterite nickel ore and smelting solid waste.

The disposal of fish scales (FSs), a proteinaceous waste material, is a challenging task, especially in underdeveloped countries. The reuse of this abundant undervalued resource to manufacture green composites is a sustainable approach to maintain the ecology by reducing waste and carbon footprint and fostering prosperity through innovative economic opportunities for fish sellers. This study investigates the utilization of fish scales as a sustainable reinforcement material and maleic anhydride-modified acrylated epoxidized soybean oil (MAESO) as the matrix for green composite development, with an emphasis on optimizing the surface treatment of FS for improved performance. Fish scale waste was subjected to water, acid and alkali treatments, and the physicochemical properties were studied in order to optimize the most suitable method of treatment. Both the treated fish scales and composites were characterized using various analytical techniques. Water-treated FS exhibited superior mechanical performance, achieving a tensile strength of 267 MPa compared with 147 MPa and 52 MPa for the acid- and alkali-treated samples, respectively. Composites reinforced with water-, acid-, and alkali-treated fish scale powder (FSP) exhibited tensile strengths of 4.38, 4.08, and 3.78 MPa, respectively, and their flexural strengths were 5.64, 3.81, and 2.80 MPa, respectively. The water-treated composite also exhibited maximum hardness (Shore D 65) and impact strength (60.81 J m⁻¹). Overall, the water-treated FSP-based composites demonstrated better mechanical, thermal, and chemical resistance, as well as reduced water uptake. These findings demonstrate the potential of fish scale-derived materials as eco-friendly, value-added fillers for sustainable composite applications.

This work presents a novel approach for the removal of chlorpyrifos (CPF) from wastewater effluents through adsorption onto agricultural wheat straw waste. Wheat straw was thermally treated to convert it into wheat straw ash and wheat straw biochar, which served as bio-adsorbents for chlorpyrifos (CPF) from aqueous media. The effect of different factors, such as the mass of WSA and WSB, the concentration of chlorpyrifos (CPF), contact time, reaction temperature, and the pH of the aqueous chlorpyrifos (CPF) solution, was analyzed to determine the set of optimum conditions at which both WSA and WSB showed their maximum adsorption capacities of 3.44 and 3.60 mg g⁻¹, respectively, which correspond to percentage removal values of 86 and 90%, respectively. The kinetic analysis revealed that the adsorption of chlorpyrifos (CPF) onto WSA and WSB is a pseudo-first-order reaction. The adsorption of chlorpyrifos (CPF) on WSA and WSB strongly obeyed the Freundlich and Temkin adsorption isotherms, whereas a relatively weak correlation was observed with the Langmuir adsorption isotherm due to the multilayered adsorption phenomenon. The thermodynamic parameters indicated that the adsorption of chlorpyrifos (CPF) on WSA and WSB is an exothermic and spontaneous process, accompanied by a decrease in orderliness. A reaction mechanism for the adsorption of chlorpyrifos onto WSA and WSB was proposed based on the electrostatic interactions, whereas a comparative analysis with the previously published adsorption studies was also carried out to establish the efficiency and novelty of the reported method.

Isoindoline-based chelates, in particular bis(arylimino)isoindolines, have shown extensive metal binding chemistry. Although this chemistry has been explored for the middle and late transition metal ions, little work has been carried out on early transition metal complexes. In this article, we present the first examples of vanadium coordinated using four bis(arylimino)isoindolines, in which the aryl groups are pyrazole, indazole, benzimidazole, and pyridine (ligands 1–4, respectively). We isolated five complexes using vanadyl sulfate or vanadyl acetylacetonate as the vanadium source. In all cases, the ligands bound in a meridional mode, and for four of the complexes, the vanadium ion was observed in the V(V) oxidation state. Three of the ligands (1–3) formed VO₂ complexes with vanadyl sulfate and vanadyl acetylacetonate, but the bis(pyridylimino)isoindoline (ligand 4) formed a V(V) oxosulfonato complex with the former starting material and a vanadyl V(IV) acetylacetonate with the latter starting material. All metal compounds were structurally elucidated by X-ray crystallographic methods, and we probed their electronic structures using DFT methods.

Methane adsorption in coal nanopores is governed by the molecular structure of coal and by nanoscale confinement. In this study, an idealized coal slit-pore model was constructed to examine pore-size-dependent methane adsorption under simplified nanopore conditions. Slit pores of 0.5, 1, 2, and 3 nm were generated by inserting vacuum layers between coal molecular cells. The coal macromolecular structure was optimized by molecular mechanics and molecular dynamics annealing, and methane adsorption was then simulated by grand canonical Monte Carlo calculations at 298 K over a fugacity range of 0.01–10 MPa. The adsorption isotherms were compared with the Langmuir–Freundlich model to evaluate adsorption capacity and surface heterogeneity. The results show that methane uptake increases with fugacity and pore size. At 10 MPa, the absolute adsorption capacity increases from 118.9 to 176.5 ml g⁻¹ as the pore size increases from 0.5 to 3 nm. The isosteric heat indicates progressive occupation of adsorption sites with different interaction strengths, and spatial adsorption maps show preferential occupation of near-surface high-affinity regions at low fugacity followed by gradual filling of pore-center regions at higher fugacity. These results provide molecular-level insight into confinement-controlled methane adsorption in idealized coal slit pores and clarify how pore size modifies adsorption capacity, adsorption energetics, and methane spatial distribution.

Direct electrocatalytic oxidation of benzene has been regarded as a promising approach for achieving a high-value phenol product, but remains a huge challenge. Herein, we construct a two-dimensional Lindqvist-type Mo₆O₁₉ cluster-based cobaltporphyrin organic framework (denoted as Co-PMOF) as an efficient electrocatalyst for the selective conversion of benzene to phenol via a hydrogen peroxide (H₂O₂)-assisted route. The well-defined hybrid framework integrates the redox-rich polyoxometalate (POM) clusters with catalytically active cobaltporphyrin units into an ordered architecture. Systematic comparison with a pristine cobaltporphyrin framework (lacking POM units) reveals that the incorporation of Mo₆O₁₉ clusters substantially enhances the catalytic performance. Density functional theory (DFT) calculations demonstrate that the Co-PMOF exhibits a lower maximum free energy change (ΔG_max) for the rate-determining step compared to its POM-free counterpart. This energetic advantage can be attributed to the synergistic interplay between the POM clusters and cobaltporphyrin centers: the POM units modulate the electronic environment of the cobalt active sites, facilitate more efficient H₂O₂ activation, optimize the formation of reactive oxygen species (*O species), and promote favorable phenol desorption, thereby effectively suppressing over-oxidation. This work establishes the Co-PMOF as a promising platform for mild and selective phenol electrosynthesis and underscores the potential of integrating POM clusters with porphyrin-based frameworks for the rational design of advanced catalysts for challenging C–H bond functionalization reactions.

The STING pathway is a promising target for cancer immunotherapy, but systemic activation by small-molecule agonists can cause adverse effects. We report a visible light-activatable STING agonist, BODIPY-MSA-2, enabling precise, light-dependent uncaging and restoration of STING activity in vitro, with potential to enable spatiotemporal control of immunostimulation.

Aqueous zinc–iodine batteries present an enormous potential owing to their high safety and low cost for large-scale energy storage. Nevertheless, their practical viability is severely impeded by the thermodynamic instability of Zn anodes, which triggers hydrogen evolution reactions (HER), uncontrolled dendritic growth and polyiodide corrosion. Herein, we propose a synergistic dual-additive strategy utilizing 3-mercaptopropionic acid (3-MPA) and ZnI₂ to stabilize Zn anodes via tailoring the electrode/electrolyte interface and modulating the primary solvation structure of Zn²⁺. Mechanistically, the preferential adsorption of MPA⁻ and I⁻ at the electrode/electrolyte interface regulates the in situ formation of an organic/inorganic hybrid solid electrolyte interphase (SEI) rich in ZnS and ZnI₂. This designed SEI effectively mitigates interfacial HER, suppresses polyiodide corrosion and facilitates uniform Zn²⁺ flux. Within the bulk electrolyte, these additives also reconstruct the solvation sheath of Zn²⁺ and disrupt the continuous hydrogen-bond network, thereby reducing the content of active water. Benefiting from the optimized interfacial environment, the Zn||Cu asymmetric cells achieve a high average coulombic efficiency of 98.7% over 5000 cycles. Moreover, Zn||I₂ full cells exhibit an exceptional capacity retention of 89.7% after 9000 cycles at 2 A g⁻¹. Ultimately, the electrochemical stability exhibited over a wide temperature range demonstrates the viability of this dual-additive strategy for practical all-climate energy storage applications.

This study presents a colorimetric method for the detection of Hg²⁺ and discrimination of cysteine (Cys) and homocysteine (Hcy) based on the peroxidase (POD)-like activity of copper-gold nanoparticles (CuAuNPs). CuAuNPs with an average size of approximately 15 nm were synthesized via a one-step reduction method and exhibited intrinsic POD-like activity, catalyzing the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H₂O₂ to produce a blue-colored product with a characteristic absorbance at 652 nm the addition of Hg²⁺ specifically enhances the catalytic activity of CuAuNPs, resulting in a distinct color change of the TMB–H₂O₂ solution from light blue to dark blue. Conversely, introduction of Cys or Hcy leads to competitive binding between their thiol (–SH) groups and Hg²⁺, forming stable S–Hg complexes, resulting in a concentration-dependent fading of the blue color. The distinct suppression extents between Cys and Hcy enable their discrimination. Under optimized conditions, the method enables quantitative detection of Hg²⁺ in the range of 100–900 nM (R² = 0.990) with a detection limit of 10 nM, and achieves satisfactory recoveries of 90.4–110.2% in spiked emollient water samples. For Cys and Hcy, linear responses are obtained over 5–40 µM (R² = 0.991; LOD = 2.5 µM) and 6–50 µM (R² = 0.992; LOD = 2.3 µM), respectively. The assay was successfully applied to rat serum samples, yielding recoveries of 99.4–108.1% (RSD < 6.2%) for Cys and 95.0–104.1% (RSD < 6.4%) for Hcy. The proposed method is simple, rapid, and selective, offering a promising nanozyme-based platform for environmental monitoring and biomedical diagnostics.