RSC Advances最新文献

This study presents a novel strategy to enhance the energy storage performance of asymmetric supercapacitors (ASCs) by utilizing nanoporous NiCoN flower structures as the positive electrode material. The NiCoN material is synthesized via a straightforward hydrothermal method, followed by calcination in a nitrogen atmosphere. The resulting electrode demonstrates exceptional electrochemical properties, including a high specific capacity of 773 C g⁻¹ (1955 F g⁻¹), excellent rate capability, and outstanding cycling stability. The hierarchical architecture of the NiCoN electrode, composed of interconnected porous nanosheets, facilitates efficient charge transfer and enhanced electrolyte ion diffusion. When paired with activated carbon (AC) as the negative electrode in the NiCoN//AC ASC configuration, the device achieves an impressive energy density of 36 W h kg⁻¹ at a power density of 775 W kg⁻¹. Moreover, the device exhibits remarkable cycling stability, retaining 85% of its initial capacitance after 5000 charge–discharge cycles. These findings underscore the potential of NiCoN as a high-performance electrode material for ASCs, offering a promising pathway for advancements in next-generation energy storage technologies.

The increasing demand for rare earth elements (REEs) necessitates the development of more efficient and environmentally friendly leaching methods. This study investigates the use of biological pretreatment to improve metal recovery from REE ore obtained from the Mushgia Khudag deposit. Characterization of the ore revealed a total REE content of 6.99%, with X-ray diffraction analysis identifying calcite and apatite as the dominant minerals, while REEs were primarily found in the forms of monazite and parisite. Experimental results demonstrated that ore pre-treated with a mixed thiobacteria culture (Tmix) achieved a 1.40-fold increase in metal recovery compared to direct acid leaching. Additionally, Bacillus sp. (B. sp.) bacteria improved recovery by 1.07-fold. Monitoring changes in pH, oxidation–reduction potential (ORP), and zeta potential during the pre-treatment process indicated that the bacteria did not directly dissolve the REEs but rather modified the surface charge and mineral structure of the ore, facilitating more efficient acid leaching. The use of Tmix bacteria for pretreatment significantly improved leaching efficiency, reduced acid consumption, and minimized environmental impact.

The recovery of precious metals from secondary sources is becoming increasingly important due to their natural scarcity and rising industrial demand. This study introduces a novel adsorbent, N-triethoxysilylpropyl-N′-benzoylthiourea-modified silica gel (TESP-BT-SG), developed for the selective recovery of platinum (Pt) and palladium (Pd) from aqueous solutions that simulate refinery wastewater. The extraction capabilities of TESP-BT-SG were compared with those of an amine-bearing adsorbent, (3-aminopropyl)triethoxy-silane-modified silica gel (APTES-SG), previously recognized for Pt and Pd recovery. Under optimal conditions, TESP-BT-SG achieved extraction efficiencies of 97% for Pt and 99% for Pd. Both adsorbents demonstrated rapid adsorption kinetics for Pd relative to Pt, reaching equilibrium within 3 hours for Pd and within 6 hours (TESP-BT-SG) and 24 hours (APTES-SG) for Pt. In solutions with elevated competing ion concentrations (5–100 mg L⁻¹), both adsorbents retained high selectivity (>97%) for Pt and Pd. Adsorption isotherms and kinetic models were applied to elucidate the adsorption mechanisms, with the Langmuir isotherm and pseudo-second-order models providing the best fits, indicating monolayer coverage and chemisorption, respectively. Notably, the APTES-SG sorbent demonstrated enhanced performance with an increased loading capacity of 2.45 mmol g⁻¹ compared to the previously reported 1.15 mmol g⁻¹, achieved through our improved synthesis method. This modified APTES-SG showed significantly higher affinity for Pd (98%), Pt (97%), and iridium (Ir) (89%) compared to previous values of 8%, 33%, and 42%, respectively. The exceptional efficiency and selectivity of these silica-anchored adsorbents underscore their potential as cost-effective solutions for industries seeking to recover precious metals.

In the absence of photoredox catalyst (PC), we have successfully achieved radical borylation and lactonization of propargyl acetates under light irradiation using N-heterocyclic carbene borane (NHC-borane), leading to the synthesis of various substituted 4-(NHC-boryl)-2(5H)-furanones. The reaction is triggered from the generation of an NHC-boryl radical, which is formed via hydrogen atom transfer (HAT) of NHC-borane with tert-butyl peroxide derived from the light-induced homolytic cleavage of di-tert-butyl peroxide (DTPB). During the lactonization process, carbon boron formation, carbon–carbon bond formation and cleavage are observed. This approach offers a facile and mild method for the construction of borylated furanones, opening a new possibility in radical borylation chemistry.

The synthesis of mesoporous carbon was successfully performed through solid–solid phase reaction employing banana peel powder as the carbon source and silica gel 60 (SG-60) as the hard template. The synthesis was initiated by hydrothermal heating to introduce the banana powder to SG-60 surface, followed by the carbonization process to form the mesoporous carbon. FTIR, Raman, XRF, and XRD characterization confirmed the success of the carbonization step, while N₂ physisorption and TEM characterization confirmed the mesoporous structure formation of the synthesized carbon with the template. At an optimum carbon-to-silica precursor ratio of 3 : 1, the synthesized carbon with SG-60 templates proceeds to a specific surface area of 476.97 m₂ g⁻¹, which is around 55-fold higher than the one synthesized without any template. Furthermore, evaluation of the capacitance performances was done by creating composite electrodes with nickel foam as the support and polyvinylidene difluoride as the binder. The evaluation was carried out using cyclic voltammetry in 3.0 M KOH, galvanic charge–discharge, and electrochemical impedance spectroscopy confirming a high correlation between the specific surface area and the specific capacitance. The banana peels-derived mesoporous carbon demonstrates a specific capacitance value of 23.1 F g⁻¹, measured using the cyclic voltammetry method. Good stability of the prepared electrode over 2500 voltammetric cycles was also demonstrated, indicating that the use of SG-60 as the hard template is suitable for synthesizing carbon with mesoporous structure from biomass.

For the first time, a novel mono Schiff base of a quinoline-based reversible fluorescent-colorimetric receptor (L) has been designed for the detection of Pb²⁺ ions in a semi-aqueous medium. The receptor L exhibited a very good selective fluorescent-colorimetric quick on–off response when exposed to Pb²⁺. The colorimetric assay showed a sensitivity of 1.2 × 10⁻⁶ M, while the fluorescent assay exhibited a sensitivity of 9.9 × 10⁻⁷ M for Pb²⁺. A 1 : 1 stoichiometric complexation between L and Pb²⁺ was determined using ESI-MS spectra and Job's plot measurements. Pb²⁺ was successfully measured using receptor L in both real samples and in an aqueous solution of the protein bovine serum albumin, as well as in the construction of an INHIBIT-type molecular logic gate.

Oxazolidinones are five-membered N-heterocycle rings containing a carbamate moiety and are known for their industrial applications as antibiotics, herbicides and electrolytes in Li batteries. Considering the projected ecological transition, they have the potential to be recognized as a green solvent according to the European standards for bio-based solvents, if they can be synthesized via an eco-friendly synthetic route. Herein, a strategy is proposed for the kilogram scale synthesis of N-isobutyl-5-methyloxazolidinone (BMOX) in two steps, starting from the renewable resources from sugar industry and without using any organic solvent. The first step was the addition of bio-based isobutylamine to chloropropanol in basic aqueous solution to afford an amino-alcohol. In the second step, to this amino-alcohol, diethyl carbonate was added in the presence of a bio-based imidazolium salt catalyst to afford the desired oxazolidinone containing more than 62% bio-based carbon atoms. This study elucidates the physicochemical properties of this new bio-sourced oxazolidinone.

A practical and efficient approach for the acid-catalysed synthesis of bis(1-imidazo[1,5-a]pyridyl)arylmethane (BimPy) derivatives has been described. Interestingly, these BimPys showed potential cytotoxicity against various cancer cell lines (SK-LU-1, MCF-7, HepG2).

1,4:3,6-Dianhydro-α-D-glucopyranose (DGP) is one of important biomass pyrolysis anhydro sugar products that derive from the cellulose and hemicellulose components. There is no reliable method for the preparation of DGP at present, which contributed to its high cost with limited market supply and restricted applied research. In this study, we provided a novel method for the synthesis of DGP from methyl 3,6-anhydro-α-D-glucopyranoside for the first time. A mild and environmentally friendly synthetic approach for 3,6-anhydro glucopyranoside was developed via the intramolecular cyclization of 6-O-tosyl glucopyranoside, promoted by a catalytic amount of TBAF. And the preparation of DGP was achieved through the stabilization effect on carbocation intermediates by HFIP in the intramolecular cyclization of 3,6-anhydro glucopyranoside. Further sensory evaluation studies revealed that DGP had a sweetness similar to that of sucrose.

Sulfinamides play a crucial role in organic synthesis and pharmaceuticals. In this study, we introduce a highly effective method for the deoxygenative radical addition to N-tritylsulfinylamine, which produces sulfinamides via photoredox catalysis. This method is compatible with a diverse array of functional groups and the resulting sulfonamides were achieved in moderate to high yields. Furthermore, the synthetic applications to access various sulfur(VI)-centered functional groups highlight the practicality of this approach.