Connection of Ru nanoparticles with rich defects enables the enhanced electrochemical reduction of nitrogen.

The electrochemical reduction of N2 into NH3 under ambient conditions is an attractive topic in the chemical industry, but the chemical inertness of N2 and the competing hydrogen evolution reaction hamper the activity and selectivity of this reaction. Herein, we connected Ru nanocrystals through a facile annealing process, which constructed intraparticle grain boundaries and stacking faults in the connection regions to enhance the N2 reduction reaction. The connected Ru nanoparticles exhibited an enhanced yield rate and faradaic efficiency for NH3 production. At -0.1 V versus RHE, the connected Ru nanoparticles exhibited a maximum yield rate of 29.3 µg cm-2 h-1 (148.0 µg mgcat-1 h-1) for NH3 production with a faradaic efficiency of 7.0%. Mechanistic study revealed that the promotion of the electrochemical reduction of N2 over connected Ru nanoparticles could be attributed to the decreased work function and facilitated electron transfer, which originated from the abundant defects in the connection region.

Nano-Montmorillonite Regulated Crystallization of Hierarchical Strontium Carbonate in a Microbial Mineralization System.

In this paper, nano-montmorillonite (nano-MMT) was introduced into the microbial mineralization system of strontium carbonate (SrCO3). By changing the nano-MMT concentration and the mineralization time, the mechanism of mineralization was studied. SrCO3 superstructures with complex forms were acquired in the presence of nano-MMT as a crystal growth regulator. At low concentrations of nano-MMT, a cross-shaped SrCO3 superstructure was obtained. As the concentration increased, flower-like SrCO3 crystals formed via the dissolution and recrystallization processes. An emerging self-assembly process and crystal polymerization mechanism have been proposed by forming complex flower-like SrCO3 superstructures in high concentrations of nano-MMT. The above research indicated that unique bionic synthesis strategies in microbial systems could not only provide a useful route for the production of inorganic or inorganic/organic composites with a novel morphology and unique structure but also provide new ideas for the treatment of radionuclides.