RSC Advances最新文献

The growing demand for electronic storage devices with faster charging rates, higher energy capacities, and longer cycle lives has led to significant advancements in supercapacitor technology. These devices typically utilize high-surface-area carbon-based materials as electrodes, which provide excellent power densities and cycling stability. However, challenges such as inadequate electrolyte interaction, hydrophobicity that impedes ion transport, and high manufacturing costs restrict their effectiveness. This study aims to enhance carbon-based materials by grafting polymer chains onto their surfaces for supercapacitor applications. A simple solution plasma process (SPP), followed by heating, prepared the polymer-grafted carbon materials. Carbon nanoparticles were synthesized from benzene through plasma discharge in liquid under ambient conditions, forming free radical sites on the carbon surface. Subsequently, benzene molecules were grafted onto the surface via radical polymerization during heating. We investigated the structural and morphological properties of the synthesized materials using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), and Raman spectroscopy. Additionally, N₂ absorption–desorption isotherms were measured, pore structure was analyzed with the Dubinin–Astakhov (DA) average pore size model, and specific surface area was determined using the Brunauer–Emmett–Teller (BET) equation for all synthesized samples. The results indicated that the grafting process was influenced by heating time and drying temperature. Furthermore, the electrical properties of the samples were evaluated using cyclic voltammetry (CV), which demonstrated enhancements in both areal capacitance and cycling stability for the polybenzene-grafted carbon compared to the non-grafted variant. This research illustrates that polymer grafting can effectively improve the performance and stability of carbon-based materials for supercapacitor applications. Future work will aim to optimize these materials for broader applications.

In recent years, there has been a discernible shift in research focus towards investigating the intricate interplay between topological states and intrinsic magnetic orders within the realm of condensed matter physics. Embedded within this evolving landscape, our study unveils an intriguing spin nodal box structure within the ferromagnetic compound K₃NiCl₆, manifesting under both spin directions. This distinctive configuration features a simplistic two-band crossing pattern that stands distinctly apart from other bands, making it amenable to both experimental validation and thorough theoretical exploration. The elucidation of the formation mechanism behind this spin nodal box has been meticulously achieved through systematic symmetry analyses, while the criteria for band crossings have been rigorously scrutinized using the Hubbard U method. Broad distribution of the surface state is derived from the Wannier tight-binding Hamiltonian and it is also well separated from the bulk band projection. More importantly, the band structure and the correlated surface states can be properly maintained even under the spin orbital coupling effect, attributed to the contributions from the light element orbitals associated with the relevant topological bands. Overall, the K₃NiCl₆ compound demonstrates a diverse array of advantages, positioning it as a promising candidate for experimental investigation, particularly in relation to its magnetic properties.

Ozone in the troposphere poses significant environmental and health risks, contributing to global warming and being linked to respiratory diseases, making it critical to find effective methods to remove ozone from the atmosphere. This study investigates the adsorption of ozone on boron nitride (BN) monolayers doped with metal-free elements, specifically carbon, silicon, oxygen, and phosphorus, using first-principles calculations based on Density Functional Theory (DFT). Our results showed that ozone adsorbed on boron nitride doped with carbon exhibited physisorption and had an adsorption energy of −0.272 eV. Ozone adsorbed on silicon-doped boron nitride dissociated into an oxygen atom and an O₂ molecule and showed chemisorption with an energy of −8.074 eV. Notably, phosphorus-doped boron nitride dissociated ozone, leading to the release of O₂ and bonding of a single oxygen atom to the boron nitride monolayer. These findings highlight how carbon and silicon-doped boron nitride can be useful in removing ozone from the troposphere and the potential of phosphorus-doped boron nitride to adsorb ozone and release a much safer O₂ molecule.

The selective oxidative dehydrogenation of cyclohexane to cyclohexene was conducted using molybdenum oxide (MoO_x) as a catalyst and hydroxyapatite (HAP) and Ca₅(OH)(PO₄)₃ as carriers. Two series of MO_x/HAP catalysts with varying MoO_x loading capacity and calcination temperature were prepared via the co-impregnation method. The impact of dispersibility and chemical environment on the catalytic performance of MoO_x was investigated. The catalysts were characterized using XRD, XPS, H₂-TPR, and UV-Vis spectra. These MoO_x/HAP catalysts were employed for the oxidative dehydrogenation (ODH) of cyclohexane to cyclohexene. MoO_x/HAP catalysts with lower loading capacity exhibited higher dispersion of MoO_x and selectivity towards cyclohexane. The calcination temperature directly influenced the chemical environment of MoO_x, thereby affecting its catalytic performance. Samples calcinated at lower temperatures (500 °C and 600 °C) demonstrated higher conversion rates for cyclohexane, while samples calcinated at higher temperatures (above 700 °C) displayed greater selectivity towards cyclohexane. At 430 °C, when the conversion rate of cyclohexane reached 13.1%, the selectivity of cyclohexene over MHAP-0.05-800 catalyst reached 58.2%.

New Re carbon nanodots with narrow size distribution, good water solubility and high cell membrane permeability were prepared from a herbal extract. They exhibited high inhibitory effects on renal cancer A498 cells and renal cell carcinoma. They could stimulate the production of ROS, induce mitochondrial dysfunction, and accelerate the release of intracellular calcium ions in the A498 cells. Transcriptomic tests were performed on A498 cells after administration, and the results were analyzed by qPCR and immunofluorescence. The results suggested that the Re carbon nanodots could downregulate the abnormally activated PI3K/AKT signaling pathway and perform cell cycle arrest in the S phase along with the inhibition of cell proliferation. Finally, in conjunction with the abnormal mitochondrial function, the Re carbon nanodots could ultimately promote the apoptosis of the A498 cells. In vivo tumor-bearing mouse experiments further showed that the Re carbon nanodots had a strong inhibitory effect on xenograft kidney cancer tumors. The prepared Re carbon nanodots have good anti-renal cancer A498 cell and renal cell carcinoma bioactivity and are expected to be a potential drug for the treatment of kidney cancer with low toxicity and high safety.

Halide perovskites have exhibited great research impact for developing innovative materials with novel properties. Here, we report the synthesis of different caesium lead bromide perovskites using different (Cs/Pb) molar ratios and fabrication of their corresponding perovskite/polyvinylidene fluoride (PVDF) composites, as well as study of their structural and UV-photodetection properties. Spin-coated perovskite/PVDF composite thin films revealed strong oriented XRD diffraction peaks along the c-axis direction (00l) with homogeneously distributed perovskite microcrystals in the polymer matrix. The high-Cs containing perovskite/PVDF composite, with Cs/Pb (3/1) molar ratio, demonstrated the highest green emission under UV light and its corresponding UV-photodetector exhibited the highest UV photo-responsivity. These results highlight the importance of structural modulation and additive manufacturing for tailoring the optoelectronic properties of halide perovskites.

The effectiveness of g-C₃N₄ as photocatalyst is hindered by the rapid recombination of photo-generated electron/hole pairs. To improve its photocatalytic performance, the incorporation of g-C₃N₄ with co-catalysts can promote charge separation efficiency and enhance redox capabilities. In our study, a two-step approach involving calcination and solvothermal method was utilized to fabricate a proficient MnO_x/g-C₃N₄ heterojunction photocatalyst with high photocatalytic activity. MnO_x is effective at capturing holes to impede the recombination of electron/hole pairs. The MnO_x/g-C₃N₄ composite shows a notable improvement in photocatalytic degradation of SMX, obtaining an 85% degradation rate, surpassing that of pure g-C₃N₄. Furthermore, the MnO_x/g-C₃N₄ composite exhibits remarkable and enduring catalytic degradation capabilities for sulfamethoxazole (SMX), even after four consecutive reuse cycles. The intermediates produced in the MnO_x/g-C₃N₄ system are found to be less hazardous to common aquatic creatures such as fish, daphnids, and green algae when compared to SMX. With its high tolerance, exceptional degradation ability, and minimal ecological risk, the MnO_x/g-C₃N₄ composite emerges as a promising candidate for eliminating antibiotics from wastewater resources.

Underground coal gasification (UCG) can convert coal resources to high-calorific value syngas, which is important for the exploration of resources and the application of clean coal technology. This study investigated the gasification process of lignite in Heilongjiang Province through an oxygen enrichment approach and examined the impact of the oxygen concentration on the gasification efficiency. Furthermore, a high-fidelity Aspen Plus process model was designed to predict the gasification products of lignite. These findings indicate that the abrupt increase in the gasification temperature and pressure is governed by the concentration of oxygen in the gasification agent. An increased concentration of oxygen results in a higher gasification temperature, thereby influencing the thermodynamic reaction processes within the gasifier. The combustion reaction of lignite transitions into a coke reaction when the oxygen concentration is elevated to 90%. At this time, the relative concentration of CO₂ generated from lignite combustion progressively diminished from 78.33%, while the relative concentrations of H₂ and CO produced through coke reactions gradually increased from 3% and 2.07%, respectively. When the oxygen concentration reaches 100%, the relative contents of H₂ and CO generated through gasification reach their respective maxima, measuring 18.90% and 23.91%. The calorific value attained a peak of 6.65 MJ N⁻¹ m⁻³ simultaneously. Furthermore, the ash yield of lignite may be a critical factor influencing the process of underground coal gasification. The gasification efficiency of lignite near T₆ is suboptimal when the oxygen concentration falls below 100%, potentially attributable to the influence of ash. In summary, lignite in Heilongjiang Province can be effectively developed through underground gasification technology via an oxygen enrichment process. Furthermore, the Aspen Plus model we developed can effectively assist in predicting the products of lignite gasification in Heilongjiang Province.

Here, two alkylated dibenzo[a,h]anthracene (DBA) derivatives with linear n-dodecyl (C12-DBA-C12) and ring-containing pentyl-cyclohexyl (Cy5-DBA-Cy5) moieties were successfully synthesized. Their chemical and thermal stability were both notably high, with the molecular arrangement of C12-DBA-C12 and Cy5-DBA-Cy5 being greatly influenced by the alkyl groups. C12-DBA-C12 formed a 2D lamellar herringbone packing structure and its blade-coated film exhibited high layered crystallinity and high carrier mobility up to 2.97 cm² V⁻¹ s⁻¹. By contrast, the arrangement of Cy5-DBA-Cy5 in the crystal exhibited a packing motif where π-cores and alkyl chains were intertwined due to the C–H⋯π proximity of cyclohexyl moieties and DBA cores. Meanwhile, Cy5-DBA-Cy5 demonstrated relatively poor film-forming capacity and moderate mobility of about 0.45 cm² V⁻¹ s⁻¹. These findings could expand the possibilities of using DBA instead of pentacene in developing high-performance OSCs for organic electronics, and offer insights into manipulating molecular arrangement through alkyl engineering.

Toward a selective and facile method for the synthesis of CF₃-containing pyrazolo[1,5-c]quinazolines, we developed a [3 + 2] cycloaddition/1,3-H shift/rearrangement/dehydrogenation cascade involving in situ generated CF₃CHN₂ and 3-ylideneoxindoles with DBU as a base. The reaction is distinguished by its mild conditions, metal-free process, operational simplicity, and broad functional group tolerance, thus presenting a convenient protocol for the construction of pyrazolo[1,5-c]quinazolines that are of interest in medicinal chemistry.