From a Molecular 2Fe‐2Se Precursor to a Highly Efficient Iron Diselenide Electrocatalyst for Overall Water Splitting

A highly active FeSe₂ electrocatalyst for durable overall water splitting was prepared from a molecular 2Fe‐2Se precursor. The as‐synthesized FeSe₂ was electrophoretically deposited on nickel foam and applied to the oxygen and hydrogen evolution reactions (OER and HER, respectively) in alkaline media. When used as an oxygen‐evolution electrode, a low 245 mV overpotential was achieved at a current density of 10 mA cm⁻², representing outstanding catalytic activity and stability because of Fe(OH)₂/FeOOH active sites formed at the surface of FeSe₂. Remarkably, the system is also favorable for the HER. Moreover, an overall water‐splitting setup was fabricated using a two‐electrode cell, which displayed a low cell voltage and high stability. In summary, the first iron selenide material is reported that can be used as a bifunctional electrocatalyst for the OER and HER, as well as overall water splitting.     

Bio‐Inspired Stable Lithium‐Metal Anodes by Co‐depositing Lithium with a 2D Vermiculite Shuttle

Progress in lithium‐metal batteries is severely hindered by lithium dendrite growth. Lithium is soft with a mechanical modulus as low as that of polymers. Herein we suppress lithium dendrites by forming soft–hard organic–inorganic lamella reminiscent of the natural sea‐shell material nacres. We use lithium as the soft segment and colloidal vermiculite sheets as the hard inorganic constituent. The vermiculite sheets are highly negatively charged so can absorb Li⁺ then be co‐deposited with lithium, flattening the lithium growth which remains dendrite‐free over hundreds of cycles. After Li⁺ ions absorbed on the vermiculite are transferred to the lithium substrate, the vermiculite sheets become negative charged again and move away from the substrate along the electric field, allowing them to absorb new Li⁺ and shuttling to and from the substrate. Long term cycling of full cells using the nacre‐mimetic lithium‐metal anodes is also demonstrated.     

Spontaneously Regenerative Tough Hydrogels

Sponges, Neofibularia nolitangere, can regenerate spontaneously after being broken down into small pieces, and the regenerated structure maintains the original appearance and function. Synthetic materials with such capabilities are highly desired but hardly achieved. Presented here is a sponge‐inspired self‐regenerative powder from a double‐network (DN) tough hydrogel. Hydrogels are regenerated from their powder form, by addition of water, with preservation of the original appearance and mechanical properties. The powder‐hydrogel‐powder cycle can be repeated multiple times with little loss in mechanical properties, analogous to the regeneration of sponges. These DN hydrogels can be conveniently stored and easily shaped upon regeneration. This work may have implications in the development of regenerative materials for coatings and adhesives.     

Biogene Polymere als Template

The presented bioinspired materials fabrication approach is focused on the development of innovative structural and functional materials. A key area in this innovative field of fundamental and applied research is the use or formation of biogenic (biopolymeric) structures and their conversion into composite materials for engineering and biomedical applications. The fundamental chemical and physical transformation processes involved in these conversions are demonstrated on selected examples.     

Total Syntheses of Daphenylline,Daphnipaxianine A,and Himalenine D

We report the total syntheses of daphenylline ( 1 ), daphnipaxianine A ( 5 ), and himalenine D ( 6 ), three Daphniphyllum alkaloids from the calyciphylline A subfamily. A pentacyclic triketone was prepared by using atom‐transfer radical cyclization and the Lu [3+2] cycloaddition as key steps. Inspired by the proposed biosynthetic relationship between 1 and another calyciphylline A type alkaloid, we developed a ring‐expansion/aromatization/aldol cascade to construct the tetrasubstituted benzene moiety of 1 . The versatile triketone intermediate was also elaborated into 5 and 6 through a C=C bond migration/aldol cyclization approach.     

DNA Origami Nanoplate‐Based Emulsion with Nanopore Function

Bio‐inspired functional microcapsules have attracted increasing attention in many fields from physical/chemical science to artificial‐cell engineering. Although particle‐stabilised microcapsules are advantageous for their stability and functionalisation potential, versatile methods for their functionalisation are desired to expand their possibilities. This study reports a water‐in‐oil microdroplet stabilised with amphiphilic DNA origami nanoplates. By utilising DNA nanotechnology, DNA nanoplates were designed as a nanopore device for ion transportation and to stabilise the oil–water interface. Microscopic examination revealed the microcapsule formed by the accumulation of amphiphilic DNA nanoplates at the oil–water interface. Ion current measurements revealed the nanoplate pores functioned as channel to transport ions. These findings provide a general strategy for the programmable design of microcapsules to engineer artificial cells and molecular robots.     

Cofactor Controlled Encapsulation of a Rhodium Hydroformylation Catalyst

Supramolecular approaches in transition‐metal catalysis, including catalyst encapsulation, have attracted considerable attention. Compared to enzymes, supramolecular catalysts in general are less complex. Enzyme activity is often controlled by the use of smaller cofactor molecules, which is important in order to control reactivity in complex mixtures of molecules. Interested in increasing complexity and allowing control over supramolecular catalyst formation in response to external stimuli, we designed a catalytic system that only forms an efficient supramolecular complex when a small cofactor molecule is added to the solution. This in turn affects both the activity and selectivity when applied in a hydroformylation reaction. This contribution shows that catalyst encapsulation can be controlled by the addition of a cofactor, which affects crucial catalyst properties.