Crystal reconstruction of binary oxide hexagonal nanoplates: monocrystalline formation mechanism and high rate lithium-ion battery applications

Highly Efficient Catalytic Oxidation of Glucose to Formic Acid over Mn-Mo Doped Carbon Nanotube

The production of formic acid (FA) from lignocellulose and its derived sugars represents a pivotal upgrading reaction in biorefinery. This work prepared a Mn-Mo doped carbon nanotube composite catalyst for the catalytic oxidation of glucose into FA in an O2 atmosphere, under extremely low Mn (3.27%) and Mo (0.40%) loading conditions, displaying a comparable performance with the traditional vanadium-based catalyst suffering from toxicity issues. It was confirmed that the doping of Mo led to the formation of MnMoOX and increased the contents of low-valence Mn species (Mn2+ + Mn3+), lattice oxygen (Olatt), and surface adsorbed oxygen (Oads) based on various characterization methods, such as XRD, XPS, TEM and ICP, which were beneficial to improve the catalytic performance. The maximum FA yield of 58.8% could be achieved over Mn9Mo1OX@MWCNT after reaction for 6 h at 140 °C, which was far more than that obtained with undoped MnOX@MWCNT (14.5%) at the identical conditions. Glyoxylic acid and arabinose were identified as two main intermediates, suggesting that the transformation of glucose into FA over Mn9Mo1OX@MWCNT involved two different paths. This work proved that manganese-based catalyst was a green alternative for upgrading lignocellulose via catalytic oxidation.

Bimetallic MnMoO4 nanostructures on carbon fibers as flexible cathode for high performance zinc-ion batteries

Aqueous zinc ion batteries (ZIBs) are promising energy storage devices due to the advantageous features of Zn. However, developing suitable cathode materials with high performance is still an urgent task for the development of ZIBs. In this work, we report on the preparation of a flexible cathode for ZIBs consisting of carbon fiber supported MnMoO₄ nanostructures protected with N-doped carbon coatings (CF/MnMoO4@NCs). The N-doped carbon coating on MnMoO₄ nanostructures can buffer volume expansion of MnMoO₄, and the CF and NCs with good electronic conductivity can facilitate quick electrons transportation in the CF/MnMoO₄@NCs system. The optimized CF/MnMoO₄@NCs cathode exhibits high capacity and good rate capability. Specifically, it delivers an outstanding discharge capacity of 663 mA h g^-1 at a current density of 0.1 A/g after 100 cycles, and at a current density of 2 A/g, the cathode can still achieve a discharge capacity of 212 mA h g^-1. This work expands the choice of cathode material and provides constructive direction on designing high-performance cathode materials for ZIBs.