The industrial use of TEMPO-mediated oxidation (TMO) reaction to produce highly fibrillated cellulose nanofibrils has been hindered by high catalyst costs, long reaction times and high reaction volumes. The hypothesis that cellulose concentration during TMO process is key to increase the process of efficiency has been confirmed. The novelty of this research is the proof-of-concept for a significant enhancement of the TMO reaction by kneading the cellulose to work in concentrations above 120 g/L. Results show that the increase of the cellulose concentration in the TMO reaction, from the traditional 10 g/L to 120 g/L, increase not only the production for the same reaction volume (1200 %) but also the pulp recovery (up to 94 %). Moreover, the oxidation time can be reduced from 42 min to only 4 min while properties of both the oxidized pulps and the final nanocellulose are similar. On the other hand, the use of buffers in the TMO reaction allows us to keep the pH constant without using NaOH, and to improve the selectivity of the carboxyl groups production. The proposed process also minimizes the final environmental impact.
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http://dx.doi.org/10.1016/j.ijbiomac.2024.129612 | DOI Listing |
ACS Nano
January 2025
Institute for Energy Electrochemistry and Urban Mines Metallurgy, School of Metallurgy, Northeastern University, Shenyang, Liaoning 110819, China.
Manganese-based layer-structured transition metal oxides are considered promising cathode materials for future sodium batteries owing to their high energy density potential and industrial feasibility. The grain-related anisotropy and electrode/electrolyte side reactions, however, constrain their energy density and cycling lifespan, particularly at high voltages. Large-sized single-crystal O3-typed Na[NiMnCuTi]O was thus designed and successfully synthesized toward high-voltage and long-lifespan sodium batteries.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China.
Layered transition metal oxide (NaTMO) cathodes are considered highly appropriate for the practical applications of sodium-ion batteries (SIBs) owing to their facile synthesis and high theoretical capacity. Generally, the phase evolution behaviors of NaTMO during solid-state reactions at high temperature closely related to their carbon footprint, prime cost, and the eventual electrochemical properties, while the thermal stability in various desodiated states associated with wide temperature fluctuations are extremely prominent to the electrochemical properties and safety of SIB devices. Therefore, in this review, the influences of sintering conditions such as pyrolysis temperature, soaking time, and cooling rates on the phase formation patterns of NaTMO are summarized.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
School of Chemical Engineering, North China University of Science and Technology, Tangshan 063009, China. Electronic address:
Transition metal oxides (TMOs) can accelerate the sluggish kinetics of vanadium redox reaction, but face challenges like limited active sites and difficulties in nanometerization, highlighting the urgent need for new TMO electrocatalysts for vanadium redox flow battery (VRFB). CoMoO features high electrochemical activity, numerous redox sites, flexible control, and short electron pathways. Herein, a high catalytic and super stable graphite felt electrode modified in situ with network cross-linking CoMoO nanosheets (CoMoO@GF) was prepared via hydrothermal and heat treatment method to enhance VRFB performance.
View Article and Find Full Text PDFACS Nano
December 2024
Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
Resolving the three-dimensional structure of transition metal oxide nanoparticles (TMO-NPs), upon self-restructuring from solution, is crucial for tuning their structure-functionality. Yet, this remains challenging as this process entails complex structure fluctuations, which are difficult to track experimentally and, hence, hinder the knowledge-driven optimization of TMO-NPs. Herein, we combine high-energy synchrotron X-ray absorption and X-ray total scattering experiments with atomistic multiscale simulations to investigate the self-restructuring of self-assembled Co-NPs from solution under dark or photocatalytic water oxidation conditions at distinct reaction times and atomic length-scales.
View Article and Find Full Text PDFJ Phys Chem C Nanomater Interfaces
October 2024
Industrial Focus Group XUV Optics, MESA+ Institute for Nanotechnology, University of Twente, Drienerlolaan 5, Enschede 7522NB, The Netherlands.
Hydrogen is a crucial element in the green energy transition. However, its tendency to react with and diffuse into surrounding materials poses a significant challenge. Therefore, developing coatings to protect system components in hydrogen environments (molecular, radicals (H*), and plasma) is essential.
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