No abstract

Metal‐N‐C is a type of attractive electrocatalyst for efficient CO2 reduction to CO. Because of the ambiguity in their atomic structures, the active sites and catalytic mechanisms of the catalysts have remained under debate. Here, the effects of N and C hybrid coordination on the activity of Ni‐N‐C catalysts were investigated, combining theoretical and experimental methods. The theoretical calculations revealed that N and C hybrid coordination greatly enhanced the capability of single‐atom Ni active sites to provide electrons to reactant molecules and strengthens the bonding of Ni to N and C in the Ni‐N‐C complexes. During the reaction process, the C and N coordination synergistically optimized the reaction energies in the conversion of CO2 to CO. A good agreement between theoretical calculations and electrochemical experiments was achieved based on the newly developed Ni‐N‐C electrocatalysts. The activity of hybrid‐coordination NiN2C2 was more than double that of single‐coordination NiN4.

Hao Chen, Jinhua Ye and co‐workers develop a self‐assembled 5‐nm‐diameter Bi5O7Br nanotubes for N2 fixation in water. They reveal in article number https://doi.org/10.1002/adma.201701774 that, under visible light irradiation, partial O atoms will escape in the form of O2 from the surface of ultrafine Bi5O7Br nanotubes, creating light‐switchable OVs‐rich ultrafine Bi5O7Br nanotubes, which are responsible for the excellent photocatalytic N2 fixation activities.

Surface modification of cationic lipoplexes has been carried out by means of a postgrafting reaction. The original lipoplexes described comprise a cationic lipid, a neutral lipid, poly(ethylene glycol)-cholesterol (with or without a targeting ligand) and DNA. Modifying their surface via a chemical, postgrafting reaction did not alter their size (approximately 100 nm) nor their ability to compact DNA, but did give a reduced zeta potential (approximately 0 mV) to afford surface neutral particles. With the modified lipoplexes nonspecific NIH3T3 cell surface binding in vitro was inhibited. Intravenous injection of the neutralized lipoplexes in mice showed decreased accumulation of the particles in the lung as compared to PEGylated cationic lipoplexes. Tumor targeting was also achieved in vivo by the addition of an RGD-PEG-Cholesterol as a lipid-ligand in the postgrafted lipoplex formulation.