LaCl3-based sodium halide solid electrolytes with high ionic conductivity for all-solid-state batteries.

To enable high performance of all solid-state batteries, a catholyte should demonstrate high ionic conductivity, good compressibility and oxidative stability. Here, a LaCl3-based Na+ superionic conductor (Na1-xZrxLa1-xCl4) with high ionic conductivity of 2.9 × 10-4 S cm-1 (30 °C), good compressibility and high oxidative potential (3.80 V vs. Na2Sn) is prepared via solid state reaction combining mechanochemical method. X-ray diffraction reveals a hexagonal structure (P63/m) of Na1-xZrxLa1-xCl4, with Na+ ions forming a one-dimensional diffusion channel along the c-axis. First-principle calculations combining with X-ray absorption fine structure characterization etc. reveal that the ionic conductivity of Na1-xZrxLa1-xCl4 is mainly determined by the size of Na+-channels and the Na+/La3+ mixing in the one-dimensional diffusion channels. When applied as a catholyte, the NaCrO2||Na0.7Zr0.3La0.7Cl4||Na3PS4||Na2Sn all-solid-state batteries demonstrate an initial capacity of 114 mA h g-1 and 88% retention after 70 cycles at 0.3 C. In addition, a high capacity of 94 mA h g-1 can be maintained at 1 C current density.

Mechanically activated calcium carbonate and zero-valent iron composites for one-step treatment of multiple pollutants.

The growing presences of conventional and emerging contaminants make the wastewater treatment increasingly difficult and expensive on a global scale. ZVI tends to be an expectable material for the detoxification of some difficult contaminants such as chlorinated solvents and nitroaromatics. In this work, together use with calcium carbonate (CaCO3), which serves as a green supporter to ZVI and also direct participant toward the purification process, has been carried out by cogrinding to give a synergistic effect, particularly for treating multiple pollutants including both inorganic and organic compositions. Based on a set of analytical methods of XRD, FTIR, SEM, XPS, and other test methods, the activation mechanism of the ball milling process and the removal performances of the prepared composites were examined. The results prove that the mechanically activated calcium carbonate and ZVI composite samples exhibited extremely high removal capacity on a variety of pollutants contaminated water. The decolorization of azo dyes is mainly attributed to the breaking of chromogenic functional group nitrogen and nitrogen double bonds, and the removal mechanism of aromatic series occurs through a hydrogenation substitution reaction. As to the inorganic pollutant removals, besides the efficient heavy metal ion precipitations, phosphate and fluoride ions are co-precipitated through the formation of fluorapatite to achieve a simultaneous and synergistic removal effect. Under the optimal reaction conditions, the concentration of PO43- is reduced from 250 to 0 mg/L, and that of F- is reduced from 51.07 to 1.20 mg/L. The prepared composite sample of ZVI rand calcium carbonate allowed simultaneous removals of both inorganic and organic pollutants, simplifying the remediation process of complicated multiple contaminations.

Mechanochemical Preparation of a H3PO4-Based Solid Catalyst for Heterogeneous Hydrolysis of Cellulose.

Cellulose saccharification to produce glucose is considered as an important approach for application of biomass resources. Solid acids as catalysts for this purpose have attracted much attention with the advantages of environmental friendliness, easy separation of products, and recyclability. In this work, a new method was introduced to prepare a H3PO4-based solid acid catalyst by simply grinding with kaolinite. Characterizations of the prepared products based on a set of analytical methods as well as cellulose hydrolysis were investigated and optimized. Loading H3PO4 on kaolinite with a mass ratio of 20% was used as a high-stability green catalyst. Cellulose hydrolysis occurred on the prepared catalyst even at much mild conditions with a low temperature of 343 K, and a yield of glucose products at 6.85% was achieved at optimized conditions. A catalytic activity of 82% remained after three cycles of use. The possible hydrolysis of cellulose under very low temperature demonstrates a potential approach for promoting biomass conversion into useful materials.

Efficient Pb removal through the formations of (basic) carbonate precipitates from different sources during wet stirred ball milling with CaCO3.

Calcium carbonate (CaCO3) may be used for lead removal. However, due to compact structure and high crystallinity of CaCO3, the utilization of CO32- is low and Pb removal only stays at the extent of physical adsorption and surface precipitation. In this research, a wet stirred ball milling process was introduced to induce nearly stoichiometric reactions between lead salts of nitrate, chloride or sulfate with CaCO3 by consequently updating fresh surfaces of CaCO3. The CaCO3 could completely dissolve in the system for the removal of Pb2+ on the same chemical molar equivalent. The removal rate reached simply over 99% with the aid of ball milling, based on the precipitations in the forms of lead carbonate (PbCO3) from soluble nitrate and basic lead carbonate (Pb3(CO3)2(OH)2) from the hardly soluble sulfate occurring in a very wide concentration range. The process offered a new path for the treatment of abandoned lead paste based on the conversion of PbSO4 to PbCO3 or Pb3(CO3)2(OH)2 as well as recycling of lead resources from multi-metal coexisting lead-containing waste solutions. These (basic) carbonates precipitates may be used as secondary resources, while achieving environmental purification.