RSC sustainability最新文献

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This study presents the green synthesis of zinc oxide (ZnO) and hematite (α-Fe₂O₃) nanoparticles (NPs) using Livistona chinensis (Chinese fan palm) leaf extract as a natural reducing and capping agent. The synthesized NPs were characterized by UV-vis spectroscopy, FT-IR, XRD, and FE-SEM to confirm their structural and morphological features. ZnO and α-Fe₂O₃ NPs exhibited UV absorption peaks at 377 nm and 418 nm, respectively. FT-IR analysis showed characteristic Zn–O and Fe–O stretching bands at 513 cm⁻¹ and 574 cm⁻¹. The average crystallite size of ZnO NPs was 25.40 nm, and that of α-Fe₂O₃ NPs was 12.37 nm. FE-SEM images revealed the triangular-shaped morphology of ZnO NPs, whereas α-Fe₂O₃ NPs were spherical. Both NPs demonstrated significant antibacterial activity. ZnO NPs showed inhibition zones of 15 ± 0.20 and 15 ± 0.90 mm against M. luteus and S. abony at 50 μg mL⁻¹, while α-Fe₂O₃ NPs were more effective against B. subtilis, S. aureus, and E. coli at 100 μg mL⁻¹ dose concentration. Antibiofilm activity was also confirmed against B. subtilis, and moderate antioxidant activity viz. 48.63% for ZnO NPs and 36.79% α-Fe₂O₃ NPs was obtained through DPPH assay. ZnO NPs achieved 79% photocatalytic degradation against malachite green (MG) dye in 90 minutes under visible light, compared to 68% by α-Fe₂O₃ NPs. Molecular docking studies revealed favourable interactions with bacterial quorum-sensing proteins; particularly, α-Fe₂O₃ NPs exhibited strong binding affinity with LasI protein (−10.33 kcal mol⁻¹). These results suggest that the synthesized NPs hold promise for medicinal and environmental applications.

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Further to the use of renewable feedstocks, sustainable biorefining requires a holistic process-level approach encompassing techno-economic and life-cycle assessments to help bridge the gap between laboratory innovation and industrial scalability.

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The leaves of Anemone coronaria (AC) and Quercus robur (QR) were evaluated as ecological corrosion inhibitors for mild steel (MS) in 1 M HCl. Individual extracts (AC and QR) and a mixture of the two were tested at concentrations ranging from 0.1 to 0.5 g L⁻¹ to investigate potential synergistic effects. The corrosion inhibition performance was assessed using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The results showed that corrosion resistance increased with inhibitor concentration, with individual efficiencies of 93.66% (AC) and 92% (QR), while the mixture achieved a maximum inhibition efficiency of 95%, indicating a synergistic effect. Fourier-transform infrared (FT-IR) spectroscopy revealed characteristic functional groups within the extracts, while scanning electron microscopy (SEM) confirmed the formation of a protective barrier on the steel surface. The adsorption process followed the Langmuir isotherm, and thermodynamic analysis revealed a spontaneous, mixed physisorption–chemisorption mechanism. DFT calculations revealed a strong interaction between the inhibitor molecules and the mild steel surface, characterized by a low energy gap (ΔE), supporting excellent anticorrosion performance at the molecular level. These findings demonstrate that the combined use of AC and QR extracts represents a novel, eco-friendly approach to corrosion inhibition, offering high efficiency, biodegradability, and minimal environmental impact.

A solvent-minimized, two-step mechanochemical protocol has been developed for the synthesis of terpene-derived phthalimides via sequential Diels–Alder cycloaddition and iodine-mediated aromatization at room temperature. Efficient conversion of isoprene and maleimides by ball-milling yields adducts in up to 86% yield, followed by in situ aromatization using iodine and 1,1,3,3-tetramethylguanidine to furnish phthalimides in up to 82% yield. The process tolerates a range of functional groups and is sensitive to steric hindrance around the diene and dienophile. This method circumvents conventional thermal protocols, offering a scalable and operationally simple route to value-added aromatics from renewable feedstocks under ambient conditions.

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The development of sustainable catalytic methods is a crucial tool for advancing green chemistry and reducing its associated environmental impact. In this study, we present an eco-friendly approach for reducing azido and nitro compounds to their corresponding amines using a heterogeneous nickel-based catalyst supported on sulfonated biochar derived from pine needle (PiNe) valorisation. The system developed, in combination with the use of NaBH₄ as a safer reducing agent in water, enables efficient transformations under mild reaction conditions, yielding excellent results. The process also incorporates a green work-up procedure that employs bio-based, non-toxic solvents, such as 2-MeTHF, to aid in product isolation and catalyst recovery, thereby significantly reducing waste generation. Moreover, recycling studies demonstrate that Ni(B)/PiNe retains its catalytic efficiency for over five consecutive cycles. This work highlights the potential of biomass-derived materials in sustainable catalysis, demonstrating that green alternatives can be as effective as traditional methods while providing a protocol that aligns with the growing demand for environmentally friendly chemistry.

This study investigates the synthesis of LaMnO₃–CeO₂ composites with varying CeO₂ contents ((100 − x)% LaMnO₃–x% CeO₂; x = 0, 10, 30, 50, 100 wt%) via an autocombustion method to elucidate their synergistic electrochemical properties. X-ray diffraction (XRD) confirmed the presence of both LaMnO₃ (LMO) and CeO₂ phases in the anticipated stoichiometric ratios. Nitrogen adsorption–desorption isotherms revealed a mesoporous structure, with the LMO–CeO₂ (70 : 30) composite exhibiting the highest specific surface area of 14.32 m² g⁻¹, as determined by the Brunauer–Emmett–Teller (BET) method. X-ray photoelectron spectroscopy (XPS) provided insights into the ion valences and chemical composition of the composites. Electrochemical performance was evaluated in a 1 M KOH aqueous electrolyte using a three-electrode configuration. The LMO–CeO₂ (70 : 30) composite demonstrated superior performance, achieving a specific capacitance of 830.3 F g⁻¹ at a scan rate of 1 mV s⁻¹ and 637.6 F g⁻¹ at a current density of 1 A g⁻¹, corresponding to an energy density of 31.9 Wh kg⁻¹ at a power density of 357.5 W kg⁻¹. These results underscore the synergistic enhancement of electrochemical properties through the integration of LaMnO₃ and CeO₂, offering significant potential for the development of high-performance materials for energy storage applications.