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22 Feb 14:59

Elastic stiffening induces one-dimensional phonons in thin Ta2Se3 nanowires

by Zhiliang Pan
Applied Physics Letters, Volume 120, Issue 6, February 2022.
Compared to extensive studies of thermal transport in two-dimensional materials, very limited attention has been paid to the corresponding phenomenon in quasi-one-dimensional van der Waals crystals. Here, we show that Ta2Se3 can be easily exfoliated into thin nanowires, indicating strong anisotropy in the bonding strength within the basal plane. Systematic thermal property measurements disclose signatures of one-dimensional phonons as the nanowire hydraulic diameter reduces below 19.2 nm with linearly escalating thermal conductivity as temperature increases and size dependence inconsistent with the classical size effect. We further show that these unusual transport properties are induced by elastic stiffening occurring for wires of <30 nm diameter.
20 Dec 16:58

A dual cellular–heterogeneous catalyst strategy for the production of olefins from glucose

by Zhen Q. Wang

Nature Chemistry, Published online: 22 November 2021; doi:10.1038/s41557-021-00820-0

A dual cellular-then-heterogeneous catalysis strategy has been used to produce olefins from glucose. 3-Hydroxy acids are made using an engineered microbial host. A hydrolytic step then provides the driving force for fatty acid deoxygenation by simple heterogeneous Lewis acid catalysis. This decarboxylation–dehydration route to olefinic products avoids the need for an additional redox input typically required for deoxygenation of unmodified fatty acids.