Ammonia-treatment assisted fully encapsulation of Fe_2O_3 nanoparticles in mesoporous carbons as stable anodes for lithium ion batteries

To improve the initial coulombic efficiency and bulk density of ordered mesoporous carbons, active Fe203 nanoparticles were introduced into tubular mesopore channels of CMK-5 carbon, which possesses high specific surface area （〉1700 m2.g-1） and large pore volume （〉1.8 cm3-g-1）. Fine Fe203 nanoparticles with sizes in the range of 5-7 nm were highly and homogenously encapsulated into CMK-5 matrix through ammonia-treatment and subsequent pyrolysis method. The Fe203 loading was carefully tailored and designed to warrant a high Fe203 content and adequate buffer space for improving the electrochemical performance. In particular, such Fe203 and mesoporous carbon composite with 47 wt% loading exhibits a considerably stable cycle performance （683 mAh.g-1 after 100 cycles, 99% capacity retention against that of the second cycle） as well as good rate capability. The fabrication strategy can effectively solve the drawback of single material, and achieve a high-performance lithium electrode material.

Effects of Fe_2O_3 Nanoparticles on Water Permeability and Strength Assessments of High Strength Self-Compacting Concrete

In this work, compressive, flexural and split tensile strength together with coefficient of water absorption of high performance self-compacting concrete containing different amount of Fe2Os nanoparticles have been investigated. The strength and the water permeability of the specimens have been improved by adding Fe2Os nanoparticles in the cement paste up to 4.0 wt%. Fe203 nanoparticle as a foreign nucleation site could accelerate C-S-H gel formation as a result of increased crystalline Ca（OH）2 amount especially at the early age of hydration and hence increase the strength of the specimens. In addition, Fe203 nanoparticles are able to act as nanofillers and recover the pore structure of the specimens by decreasing harmful pores to improve the water permeability. Several empirical relations have been presented to predict the flexural and the split tensile strength of the specimens by means of the corresponding compressive strength at a certain age of curing. Accelerated peak appearance in conduction calorimetry tests, more weight loss in thermogravimetric analysis and more rapid appearance of peaks related to hydrated products in X-ray diffraction results indicate that Fe203 nanoparticles up to 4 wt% could improve the mechanical and the physical properties of the specimens.