Phosphorus has been regarded as one of the most promising next-generation lithium-ion battery anode materials, because of its high theoretical specific capacity and safe working potential. However, the shuttle effect and sluggish conversion kinetics hamper its practical application. To overcome these limitations, we decorated SnO 2 nanoparticles at the surface of phosphorus using an electrostatic self-assembly method, in which SnO 2 can participate in the discharge/charge reaction, and the Li 2 O formed can chemically adsorb and suppress the shuttle of soluble polyphosphides across the separator. Additionally, the Sn/ Li−Sn alloy can enhance the electrical conductivity of the overall electrode. Meanwhile, the similar volume changes and simultaneous lithiation/delithiation process in phosphorus and SnO 2 /Sn are beneficial for avoiding additional particle damage near two-phase boundaries. Consequently, this hybrid anode exhibits a high reversible capacity of ∼1180.4 mAh g −1 after 120 cycles and superior high-rate performance with ∼78.5% capacity retention from 100 to 1000 mA g −1 .

Developing nonprecious metal catalysts with fast charge transfer ability, abundant active sites, and easy recovery is of great significance toward sodium borohydride (NaBH 4 ) hydrolysis for hydrogen (H 2 ) production in alkaline solutions. Herein, magnetically separated nitrogen-doped carbonsupported cobalt oxide (Co x O y @NC) nanoparticles were prepared successfully by converting pyrazine-based covalent organic frameworks (COFs). Due to the porous structure and nitrogen-rich characteristics of the precursor, the prepared catalyst Co x O y @NC exhibited good conductivity and charge transfer ability. Cobalt oxide nanoparticles and nitrogen-doped carbon matrix are bonded by the Co−N bond, which makes full use of the conductivity of the substrate and the high activity of the cobalt oxide catalyst. Therefore, Co x O y @NC exhibits an excellent synergistic effect between Co x O y and NC. The H 2 generation rate reaches a maximum of 2082.13 mL/min/g from NaBH 4 in alkaline solutions. In addition, Co x O y @NC also exhibits good magnetic separation capability, which greatly simplifies the catalyst separation process. Density functional theory (DFT) calculation results indicate that Co 2+ is the dominant active component in the heterogeneous catalyst Co x O y @NC. This work broadens new horizons for the development of COFs derivative catalysts for hydrogen production from sodium borohydride hydrolysis.

No abstract