There is no doubt that rechargeable batteries will play a huge role in the future of the world. Sodium-ion (Na-ion) batteries might be the ideal middle-ground between high performance delivered...

A scalable solvothermal technique is reported for the synthesis of a photocatalytic composite material consisting of orthorhombic Ta3N5 nanoparticles and WOx≤3 nanowires. Through X-ray diffraction and X-ray photoelectron spectroscopy, the as-grown tungsten(VI) sub-oxide was identified as monoclinic W18O49. The composite material catalysed the degradation of Rhodamine B at over double the rate of the Ta3N5 nanoparticles alone under illumination by white light, and continued to exhibit superior catalytic properties following recycling of the catalysts. Moreover, strong molecular adsorption of the dye to the W18O49 component of the composite resulted in near-complete decolourisation of the solution prior to light exposure. The radical species involved within the photocatalytic mechanisms were also explored through use of scavenger reagents. Our research demonstrates the exciting potential of this novel photocatalyst for the degradation of organic contaminants, and to the authors’ knowledge the material has not been investigated previously. In addition, the simplicity of the synthesis process indicates that the material is a viable candidate for the scale-up and removal of dye pollutants on a wider scale.

Sodium ion batteries represent a drop-in technology and a more sustainable alternative to Li-ion, but higher energies and power levels are required to meet the demands required by a greener electrification. Here, the design of an anode-free sodiumion battery is presented and its performances discussed in terms of reduced mass and high power capabilities. The cell consists of an Iron Hexacyanoferrate-reduced Graphene Oxide composite as cathode material whose synthesis is tailored to achieve minimal structural defects (3%) and water content. Its high-potential redox couple FeLS(C) is stabilized at high rates, granting the full cell with high discharge voltage and power. As negative substrate, a carbon coated aluminum foil was adopted for in situ plating/stripping of Na metal, showing very small voltage hysteresis up to an applied current of 2 mA/cm 2. Overall, this simplified full cell architecture can deliver up to 340 Wh/kg and 500 W/kg at nominal 1C retaining 80% in 250 cycles, with the possibility of delivering 9000 W/kg at 20C. Bridging the boundaries between batteries and supercapacitors, this research aims to expand the range of possible applications for Na-ion technology.

A 12.5 at% replacement of Sb with Bi in Sb2Te3leads to a Na-ion battery anode material with enhanced resistance to mechanical degradation when used as micron-sized powder and not as a nanostructured carbon composite.

Two different high-pressure and -temperature synthetic routes have been used to produce only the second-known pentavalent CaIrO3-type oxide. Postperovskite NaOsO3 has been prepared from GdFeO3-type perovskite NaOsO3 at 16 GPa and 1135 K. Furthermore, it has also been synthesized at the considerably lower pressure of 6 GPa and 1100 K from a precursor of hexavalent Na2OsO4 and nominally pentavalent KSbO3-like phases. The latter synthetic pathway offers a new lower-pressure route to the postperovskite form, one that completely foregoes any perovskite precursor or intermediate. This work suggests that postperovskite can be obtained in other compounds and chemistries where generalized rules based on the perovskite structure may not apply or where no perovskite is known. One more obvious consequence of our second route is that perovskite formation may even mask and hinder other less extreme chemical pathways to postperovskite phases.