A highly atom-economic procedure for the preparation of reduced graphene oxide/Mn3O4 (rGO/Mn3O4) composites is reported. Pristine graphene oxide/manganese sulfate (GO/MnSO4) suspension produced by modified Hummers method is utilized with high efficiency, which has been in situ converted into GO/Mn3O4 hybrid composite by air oxidation, then into rGO/Mn3O4 composite by means of dielectric barrier discharge (DBD) plasma-assisted deoxygenation. The Mn3O4 content of the rGO/Mn3O4 composites can be readily tailored. It is observed that Mn3O4 nanoparticles of 15-24 nm are well-dispersed on graphene sheets with Mn3O4 loading as high as 90%. The specific capacitance of the as-prepared rGO/Mn3O4 hybrids with 90% Mn3O4 reaches 193 F g(-1) when employed as the electrode material in neutral Na2SO4 electrolyte solutions (76 F g(-1) for pristine graphene and 95 F g(-1) for pure Mn3O4), which indicates the positive synergetic effects from both graphene and attached Mn3O4. The method developed in this study should offer a new technique for the large scale and highly atom-economic production of graphene/MnOx composites for many applications.
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http://dx.doi.org/10.1039/c3nr33700f | DOI Listing |
J Org Chem
January 2025
Laboratory of Organo Catalysis and Synthesis, Department of Chemistry, Visvesvaraya National Institute of Technology (VNIT), Nagpur, Maharashtra 440010, India.
A practically intriguing catalytic domino methodology has been developed for the synthesis of highly functionalized pyran and ethene-1,1,2-tricarbonitrile derivatives in a single-pot operation. The -dicyano olefins and the corresponding epoxide were taken as the reactive partners in the presence of a hydrogen bond donor (HBD)-catalyzed condition. The reaction was found to be highly efficient in terms of the formation of sequential C-C and O-C bonds along with an exceptional C-C coupling step through a metal-free organocatalytic pathway.
View Article and Find Full Text PDFSmall
December 2024
Key Laboratory of Catalytic Conversion and Clean Energy in Universities of Shandong Province, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong, 273165, P. R. China.
Nanostructured Faradaic materials show extraordinary promise for capacitive deionization (CDI) toward the relief of global freshwater scarcity. But at present, there exist at least two shortages for the development of CDI electrode materials. In laboratory studies, evaluating their desalination performance is usually based on low mass loadings (<1 mg cm), which is far behind the practical demand for fabricating high-mass-loading CDI electrodes or devices.
View Article and Find Full Text PDFJ Org Chem
December 2024
Green Pharmaceutical Technology Key Laboratory of Luzhou City, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, P. R. China.
A cerium-catalyzed C-H alkylation of -sulfonyl ketimines with low-cost and readily available alkanes as alkyl sources was developed. This transformation proceeded through the synergy of photoinitiated ligand-to-metal charge transfer (LMCT) using a chlorine radical as an HAT reagent and air as a green oxidant. A series of alkylated -sulfonyl ketimines were synthesized with moderate to good yields in a highly atom-economic manner under chemical oxidant-free conditions.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, 999077, Hong Kong SAR, China.
Hydroboration of allenes is powerful and atom-economic approach to the synthesis of organoboranes, such as the highly versatile allylboranes. However, regarding regiocontrol, existing methods uniformly deliver the boron functionality to the less hindered β- or γ-position, but not the α-position. The latter is particularly challenging for allenes with substantial steric difference between the two terminals and lacking electronic bias (e.
View Article and Find Full Text PDFJ Environ Sci (China)
June 2025
CAS Key Laboratory of Science and Technology on Applied Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address:
Green and atom-economic depolymerization of lignin remains a great challenge due to its complex non-repetitive structure and the inert property for chemo-digestion. A redox-neutral lignin depolymerization system without the use of extra oxidant and/or reductant over a Co-NC catalyst has been developed in this work, providing the first non-noble metal heterogeneous catalytic system for redox-neutral valorization of lignin. Mechanistic studies based on control reactions and deuterium labeling experiments suggest that the reaction proceeds via a metal-catalyzed dehydrogenation of C-OH to afford a carbonyl intermediate, followed by C-O bond cleavage (via hydrogenolysis) to afford monophenols and aromatic ketone products.
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