Reactions

16 pages, 1415 KB

Open AccessArticle

Decolorization and Detoxification of Synthetic Dyes by Trametes versicolor Laccase Under Salt Stress Conditions

by Thaís Marques Uber, Danielly Maria Paixão Novi, Luana Yumi Murase, Vinícius Mateus Salvatori Cheute, Samanta Shiraishi Kagueyama, Alex Graça Contato, Rosely Aparecida Peralta, Adelar Bracht and Rosane Marina Peralta

Reactions 2025, 6(4), 53; https://doi.org/10.3390/reactions6040053 - 3 Oct 2025

Abstract

Fungal laccases are promising oxidative enzymes for bioremediation applications, particularly in the degradation of synthetic dyes present in industrial effluents. Here, we evaluated the inhibitory effects of sodium chloride (NaCl) and sodium sulfate (Na₂SO₄) on the activity of Trametes versicolor laccase and its ability to decolorize Congo Red (CR), Malachite Green (MG), and Remazol Brilliant Blue R (RBBR). Enzyme assays revealed concentration-dependent inhibition, with IC₅₀ values of 0.22 ± 0.04 M for NaCl and 1.00 ± 0.09 M for Na₂SO₄, indicating stronger inhibition by chloride. Kinetic modeling showed mixed-type inhibition for both salts. Despite this effect, the enzyme maintained significant activity: after 12 h, decolorization efficiencies reached 95 ± 4.0% for MG, 88 ± 3.0% for RBBR, and 75 ± 3.0% for CR, even in the presence of 0.5 M salts. When applied to a mixture of the three dyes, decolorization decreased only slightly in saline medium (94.04 ± 4.0% to 83.43 ± 5.1%). FTIR spectra revealed minor structural changes, but toxicity assays confirmed marked detoxification, with radicle length in lettuce seeds increasing from 20–38 mm (untreated dyes) to 41–48 mm after enzymatic treatment. Fungal growth assays corroborated reduced toxicity of treated dyes. These findings demonstrate that T. versicolor laccase retains functional robustness under ionic stress, supporting its potential application in saline textile wastewater remediation. Full article

(This article belongs to the Topic Green and Sustainable Catalytic Process)

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10 pages, 1449 KB

Open AccessArticle

Enhanced Cycling Stability of High-Voltage Sodium-Ion Batteries via DFEC-Driven Fluorinated Interface Engineering

by Xin Li, Yali Yao and Xinying Liu

Reactions 2025, 6(4), 52; https://doi.org/10.3390/reactions6040052 - 1 Oct 2025

Abstract

With their considerable capacity and structurally favorable characteristics, layered transition metal oxides have become strong contenders for cathode use in sodium-ion batteries (SIBs). Nevertheless, their practical deployment is challenged by pronounced capacity loss, predominantly induced by unstable cathode–electrolyte interphase (CEI) at elevated voltages. In this study, difluoroethylene carbonate (DFEC) is introduced as a functional electrolyte additive to engineer a robust and uniform CEI. The fluorine-enriched CEI effectively suppresses parasitic reactions, mitigates continuous electrolyte decomposition, and facilitates stable Na⁺ transport. Consequently, Na/NaNi_1/3Fe_1/3Mn_1/3O₂ (Na/NFM) cells with 2 wt.% DFEC retain 78.36% of their initial capacity after 200 cycles at 1 C and 4.2 V, demonstrating excellent long-term stability. Density functional theory (DFT) calculations confirm the higher oxidative stability of DFEC compared to conventional solvents, further supporting its interfacial protection role. This work offers valuable insights into electrolyte additive design for high-voltage SIBs and provides a practical route to significantly improve long-term electrochemical performance. Full article

(This article belongs to the Special Issue Feature Papers in Reactions in 2025)

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20 pages, 4097 KB

Open AccessArticle

Ethylene and 1-butene Oligomerization with Benzimidazole Complexes of Nickel and Iron: A Case of Tandem Reaction

by Nelson N. dos Santos, Marcos F. Silva, Alexandre F. Young, Marcos L. Dias and Mariana M. V. M. Souza

Reactions 2025, 6(4), 51; https://doi.org/10.3390/reactions6040051 - 24 Sep 2025

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Abstract

The coordination chemistry of benzimidazole ligands combines σ donation and π backbonding. Owing to this electronic flexibility, benzimidazole ligands stabilize both electron deficient and electron-rich transition states in the catalytic cycle of Ziegler-Natta polymerizations. In this study, Fe(III) and Ni(II) complexes of 2-substituted-benzimidazoles were tested as catalysts for ethylene and 1-butene oligomerization. The tests realized in toluene yielded mainly butenes and minor amounts of hexenes. When dichloromethane was used as solvent, a tandem reaction took place and 1-butene produced by ethylene dimerization was further oligomerized, yielding octenes and dodecenes as main products. All tested catalysts exhibited moderate selectivity for 1-octene, indicating 1-ω enchainment in 1-butene dimerization. Beyond catalytic tests, a theoretical study of the ligand 2,2′-(furan-2,5-diyl)bis(1H-benzimidazole) confirmed the planar structure of this compound as evidenced by NMR spectroscopy. Full article

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Reactions, Volume 6, Issue 4 (December 2025) – 3 articles

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