Category Chemistry/Nanotechnology

The perovskite material changes size when exposed to light. Reproduced with permission from reference 1.© 2017 WILEY‐VCH Verlag GmbH & Co.

A crystalline material that changes shape in response to light could form the heart of novel light-activated devices. Perovskite crystals have received a lot of attention for their efficiency at converting sunlight into electricity, but new work by scientists at KAUST shows their potential uses extend far beyond the light-harvesting layer of solar panels. Photostriction is the property of certain materials to undergo a change in internal strain, and therefore shape, with exposure to light...

Charge screening in ferroelectric Pb(Zr,Ti)O3 nanorods was used to control their domain pattern. The c-domain fraction markedly increased with as the rod width decreased, while the a-domain formation prevailed by metallization of their sidewall. All the observed results could be explained by the depolarizing field, arising from the imperfect charge screening. This approach could be expanded to other low-dimensional nanoscale ferroelectric systems. Credit: Tomoaki Yamada

Scientists have taken control of the configuration of domains in nanorod- and thin-film ferroelectric systems. Many next-generation electronic and electro-mechanical device technologies hinge on the development of ferroelectric materials...

Dendritic Hematite Nanoarray Photoanode Modified with a Conformal Titanium Dioxide Interlayer for Effective Charge Collection. Angewandte Chemie International Edition, 2017; DOI: 10.1002/anie.201705772

Modification of a hematite photoanode by a conformal titanium dioxide interlayer for effective charge collection. Earth-abundant, cheap metals are promising photocatalytic electrode materials in artificial photosynthesis. The nanostructured electrode benefits from two separate effects. This design combining nanostructure with chemical doping may be exemplary for improved “green” photocatalytic systems.

With the help of a catalyst, sunlight can drive the oxidation of water to oxygen and the release of electrons for current generation, a process also called artificial photosynthesis...

(a) Electron backscatter diffraction (EBSD) phase image showing the lamella microstructure of layered austenite grains embedded in tempered martensite matrix. (b) The dislocation structures in martensite as enlarged in transmission electron microscopy (TEM) image. (c) TEM image showing the elongation of dislocation cell structure after the 8% tensile strain. (d) TEM image confirming the transformation of metastable austenite to martensite after 16% tensile strain. Credit: The University of Hong Kong

Automotive, aerospace and defence applications require metallic materials with ultra-high strength...