Bettina V. Lotsch — Page 2

arXiv2014

Ultrafast Li Electrolytes Based on Abundant Elements: Li$_{10}$SnP$_2$S$_{12}$ and Li$_{11}$Si$_2$PS$_{12}$

We report on the synthesis and characterization of two solid electrolytes, Li$_{10}$SnP$_2$S$_{12}$ and Li$_{11}$Si$_2$PS$_{12}$, which are based exclusively on abundant elements. Both compounds feature extremely high Li ion diffusivities, with the Si-based material even surpassing the present record holder, the related electrolyte Li$_{10}$GeP$_2$S$_{12}$. The structure and dynamics were studied with multiple complementary techniques and the macroscopic diffusion could be traced back to fast Li ion hopping in the crystalline lattice.

cond-mat.mtrl-sci↗

arXiv2014

A Hydrazone-based Covalent Organic Framework for Photocatalytic Hydrogen Production

Covalent organic frameworks (COFs) have recently emerged as a new generation of porous polymers combining molecular functionality with the robustness and structural definition of crystalline solids. Drawing on the recent development of tailor-made semiconducting COFs, we here report on a new COF capable of visible-light driven hydrogen generation. The COF is based on hydrazone-linked functionalized triazine and phenyl building blocks and adopts a layered structure with a honeycomb-type lattice featuring mesopores of 3.8 nm and the highest surface area among all hydrazone-based COFs reported to date. When illuminated with visible light, the COF continuously produces hydrogen from water without signs of degradation. With their precise molecular organization and modular structure combined with high porosity, photoactive COFs represent well-defined model systems to study and adjust the molecular entities central to the photocatalyic process.

cond-mat.mtrl-sci↗