New Journal of Chemistry最新文献

Given the pervasive existence and toxicity of organic dyes, especially benzidine-derived dyes, it is imperative to develop effective wastewater treatment solutions. In this study, a straightforward method was developed to prepare succinic anhydride-modified glucose-based carbon microspheres (SA-CMS). The key functionalization step was performed in molten succinic anhydride without adding organic solvents. By adding a certain amount of succinic anhydride as a functionalization reagent to the reaction system, a large number of functional groups were generated on the surface of the glucose-based carbon microspheres (CMS), which improved their adsorption capacity and selectivity for the cationic dyes, methylene blue (MB) and methyl violet (MV). The maximum adsorption capacity Q_m of SA-CMS for MB and MV reached 571.43 mg g⁻¹ and 500.00 mg g⁻¹ at pH 8 and 25 °C, respectively, and the adsorption data of the cationic dyes by SA-CMS were in accordance with the Langmuir isotherm model and the pseudo-second-order model. SA-CMS demonstrated a stronger affinity for cationic dyes (500.00–571.43 mg g⁻¹) than for anionic dyes (44.38–118.33 mg g⁻¹), and the removal rates of MB and MV by SA-CMS remained above 75% after five adsorption–desorption cycles, confirming its highly selective separation ability and reusability. Systematic characterization revealed that the adsorption mechanisms of MB and MV by SA-CMS mainly included hydrogen bonding and electrostatic interactions. These results indicate that SA-CMS, a green carbon-based adsorbent material prepared by hydrothermal carbonization of glucose, is an environmentally friendly, low-cost, and effective adsorbent with high reusability, offering significant potential for removing cationic dyes from wastewater. Additionally, this adsorbent also exhibits an enhanced adsorption capacity with an increase in ionic strength, which is a systematically studied phenomenon. It is expected to be valuable in industrial wastewater treatment, with considerable economic and social benefits.

Mononuclear palladium(II) complexes (Pd8MOQL^1–4) were obtained by reacting 8-methyl-2-oxo-1,2-dihydroquinoline-3-carboxaldehyde-4(N)-substituted thiosemicarbazones (8MOQL^1–4) with K₂[PdCl₄]. The ligands (8MOQL^1–4) and the corresponding Pd(II) complexes (Pd8MOQL^1–4) were characterized by FT-IR, UV-visible, and ¹H NMR spectroscopic analyses. The monomeric nature of the complexes Pd8MOQL¹, Pd8MOQL² and Pd8MOQL⁴ was revealed by X-ray crystallographic analysis, and the stoichiometry of the complex Pd8MOQL³ was confirmed from its mass spectral data. The ligands coordinated with the palladium ion through quinolone oxygen, azomethine nitrogen and thiolate sulphur atoms. The catalytic potential of the synthesized complexes was revealed through the bromoamination reactions of various α,β-unsaturated keto alkenes in the presence of N-bromosuccinimide (NBS) and p-toluenesulfonamide as bromo and amino sources, respectively. Optimization studies indicated that the complex Pd8MOQL² exhibited the best catalytic efficiency among the synthesized complexes. Appreciable yield of the coupled products was obtained with minimal catalyst loading (0.05 mol%), and the obtained chiral products were confirmed through ¹H and ¹³C NMR, mass and CD spectroscopy analyses. A plausible mechanism was proposed for the formation of bromoaminated products based on the isolated α-bromo β-chloro dihalogenated keto alkane, and theoretical confirmation of the optimized intermediates (C, D1 and F1) and final product (P1) was performed through DFT studies.

The harmonic and anharmonic rate constants, kinetic parameters, and thermodynamic parameters of the combustion mechanism for NH₃/PODE₁ mixed fuels were calculated over a temperature range from 300 K to 4000 K. The influence of both pressure and tunneling effects was thoroughly investigated. In this study, bimolecular reactions show a more pronounced anharmonic effect than unimolecular reactions. Analysis of the frequencies of the reactions studied in this work reveals that the harmonic and anharmonic frequencies are primarily distributed in the high-frequency (2500–4000 cm⁻¹) and low-frequency (0–1500 cm⁻¹) regions. In the reactions of PODE₁ with radicals NO₂ and NH₂, the primary consumption pathway for PODE₁ is the reaction with NH₂. In summary, the computational outcomes have enhanced the accuracy of the combustion reaction mechanism for NH₃/PODE₁ mixed fuels.

Layered double hydroxides (LDHs) have attracted a lot of interest because of their tunable layered structure, high surface area, and redox activity, which lead to good electrochemical energy storage performance. The electrochemical performance of carbonate-intercalated Ce-doped NiCoAl LDH, synthesized by a simple hydrothermal route followed by anion exchange, was investigated in this work. The structural and morphological characterizations confirmed the effective doping and intercalation, which enhanced the electrochemical properties. Electrochemical studies showed that carbonate-intercalated Ce-doped NiCoAl LDH had the highest specific capacitance of about 2500 F g⁻¹ at 10 mV s⁻¹, which delivered both high rate capability and outstanding long-term cycling stability of about 88.4% after 10 000 cycles. These results show that carbonate-intercalated Ce-doped NiCoAl LDH is a promising candidate for high-performance energy storage.

Natural pyrite possesses inherent advantages for heavy metal immobilization due to its natural abundance and low sulfur content, yet its effectiveness is limited by its low surface area and scarce active sites. Herein, a straightforward phosphate modification strategy via ball-milling was employed to enhance the cadmium removal performance of natural pyrite. The obtained phosphate-modified natural pyrite (FeS₂@P^bm) exhibited a markedly improved Cd(II) adsorption capacity (43.77 mg g⁻¹), which was 1.83 times than that of ball-milled natural pyrite without phosphate modification (FeS^bm₂, 23.93 mg g⁻¹). The adsorption process fitted well with the pseudo-second-order kinetic model and Langmuir isotherm, indicating a monolayer adsorption process predominantly controlled by chemisorption. Characterizations revealed that the Cd(II) adsorption mechanisms on FeS₂@P^bm involved electrostatic attraction, surface complexation, and chemical precipitation. The phosphate modification altered the surface functional groups and surface potential of FeS₂@P^bm, facilitating the chemical and electrostatic adsorption of Cd(II). Additionally, FeS₂@P^bm exhibited substantial potential for the removal of multiple metal ions, including As(III), Pb(II), Cu(II), Ag(I), Hg(II), and Zn(II). This study offers a unique strategy for fabricating highly cost-effective mineral adsorbents through phosphate modification via ball-milling, enabling effective heavy metal removal from wastewater.

We report a mild and efficient copper-catalyzed method for synthesizing amino-substituted pyrrolo[1,2-a]quinoxaline and indolo[1,2-a]quinoxaline derivatives via the insertion of o-benzoylhydroxylamines into aryl isocyanides. This one-pot cascade transformation enables the simultaneous formation of C–N and C–C bonds, facilitating the efficient construction of heterocycles from diverse o-benzoylhydroxylamines and isocyanide-substituted arene substrates.

A series of propyl phosphonic anhydride (T3P®)-mediated oxidative dimerization reactions, of aromatic and aliphatic thioamides, for the efficient synthesis of 3,5-disubstituted 1,2,4-thiadiazoles has been developed. T3P® has been demonstrated to be an efficient, greener, safer and practical reagent for this transformation, affording good yields under mild conditions. Overall, this approach provides an environmentally benign route to 3,5-disubstituted 1,2,4-thiadiazoles.

Several water bodies have been affected by potentially toxic elements and pharmaceutical derivatives. To eliminate these contaminants from the aquatic environment, wastewater treatment techniques must be developed. In this study, low cost Bryophyllum pinnatum (BP) was pretreated with acid and used as a promising adsorbent for cadmium ion (Cd²⁺) and ciprofloxacin (CIP) uptake from aqueous solution. The adsorption factors (pH, dosage and initial adsorbate concentration) were estimated after characterization of pretreated BP using Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, N₂ adsorption/desorption and zeta potential analyses. Optimum adsorption was achieved at pH 11 using an adsorbent dosage of 0.25 g, with monolayer uptake capacities of 18.51 and 11.66 mg g⁻¹ for Cd²⁺ and CIP, respectively. The Freundlich and Temkin isotherms provided the best fit for Cd²⁺ and CIP uptake, respectively, with low error values. The uptake of Cd²⁺ and CIP on the surface of pretreated BP is best explained by pseudo-second order kinetics, signifying that chemisorption and intra-particle diffusion of the adsorbates on the surface sites occurred in three stages. The adsorption process occurred spontaneously in an endothermic manner based on thermodynamic evaluation. The extent of the reusability of pretreated BP was tested after five consecutive cycles, which further proved economic viability. The characterization and adsorption analysis demonstrated the dominant role of electrostatic attraction during Cd²⁺ and CIP removal, accompanied by pore filling, hydrogen bonding and hydrophobic interactions. The present work affirms that pretreated BP is promising for application in Cd²⁺ and CIP removal from aqueous media.

Aqueous zinc-ion batteries are regarded as one of the most promising candidates for large-scale energy storage devices. However, zinc anodes suffer from uncontrollable dendrite growth and side reactions such as hydrogen evolution at the electrolyte interface, which severely compromise battery lifespan. This study employs pulse electrodeposition to fabricate a composite modified zinc anode (MBTG) incorporating micron-sized barium titanate (MBT) and graphene (Gr). Results indicate that when MBT is added at 0.8 g L⁻¹ and Gr at 0.04 g L⁻¹, the assembled symmetric cell exhibits lower voltage hysteresis and longer cycling performance compared to the bare zinc cell, achieving stable cycling for over 350 hours at both 5 mA cm⁻² and 2 mA cm⁻². Furthermore, after 650 constant-current cycles at a current density of 0.5 A g⁻¹, the assembled cell exhibited a capacity retention rate of 73%, significantly outperforming the bare zinc-assembled cell. Electrochemical tests revealed that the synergistic effect of MBT and Gr not only optimized the growth of the Zn(002) crystal plane but also enhanced zinc ion transport kinetics and ionic conductivity, facilitating uniform zinc deposition. Consequently, the composite anode exhibited lower interfacial resistance and improved corrosion resistance. This work provides a promising pathway for preparing long-cycle zinc anodes and high-performance AZIBS.

Much attention has been paid to the catalytic performance of cobalt-based nanocrystalline catalysts toward advanced oxidation of p-nitrophenol (PNP) and other organic matters. However, the application of amorphous Co-based catalysts is rare. In this study, we show that both amorphous Co–B–O–C materials prepared in the temperature range of 150–600 °C and Co–B–O–C room temperature solution are effective catalysts in activating peroxymonosulfate (PMS) for the degradation of PNP in water. The results of radical quenching experiments confirmed that the main reactive oxygen species during the advanced oxidation reaction of PNP was O₂˙⁻. Electron paramagnetic resonance analysis results showed strong signals of ¹O₂, which was believed to be transformed from O₂˙⁻. The amorphous Co–B–O–C sample could degrade 91.2% of PNP in 1 min after recycling the sample five times. Co–B–O–C also had good catalytic performance for the degradation of 2-nitrophenol. Our results provide new insight into the design of cobalt-based catalysts for degrading organic pollutants in water.