Transition-metal compounds have received extensive attention from researchers due to their high reversible capacity and suitable voltage platform as potassium-ion battery anodes. However, these materials commonly feature a poor conductivity and a large volume expansion, thus leading to underdeveloped rate capability and cyclic stability. Herein, we successfully encapsulated ultrafine CoP and CoSb nanoparticles into rich N-doped carbon nanofibers (NCFs) via electrospinning, carbonization, and phosphorization (antimonization). The N-doped carbon fiber prevents the aggregation of nanoparticles, buffers the volume expansion of CoP and CoSb during charging and discharging, and improves the conductivity of the composite material. As a result, the CoP/NCF anode exhibits excellent potassium-ion storage performance, including an outstanding reversible capacity of 335 mA h g −1 , a decent capacity retention of 79.3% after 1000 cycles at 1 A g −1 and a superior rate capability of 148 mA h g −1 at 5 A g −1 , superior to most of the reported transition-metalbased potassium-ion battery anode materials.
A water-processable blue fluorescent silver nanoparticle@graphene–polymer composite (Ag@G–pNIPAM) consisting of graphene coated with a thermally responsive poly-(N-isopropylacrylamide) (pNIPAM) shell is prepared. The pNIPAM shell swells or collapses as a function of temperature, serving as a means to trap silver nanoparticles in solution and get them sufficiently close to the graphene core to provide fluorescence enhancement based on the local surface plasmon resonance (LSPR) effect. The unique thermoresponsive properties and high enhancement ratio of the material should find application in solution fluorescence enhancers and a variety of biomedical applications, such as cellular uptake, sensing and imaging.
In the propagating process along metal surface, surface plasmon polaritons (SPPs) mainly decay into thermal loss or release into photons, while a part of them were converted into electrons with high energy termed as hot electrons, which have great significance in photonics and electronics. In this work, the generation of plasmonic hot electrons was ascertained in the nanoparticle-film system through plasmon-driven surface catalysis (PDSC) reactions. The surface-enhanced Raman scattering (SERS) spectra of p,p'-dimercaptoazobenzene (DMAB) catalyzed by 4-nitrobenzenethiol (4NBT) experimentally demonstrated the essential catalysis electrons were generated in this hybrid plasmon mode. The results pointed out the priority of plasmonic hot electron generation in the dimer-film gap compared to the monomer-film gap which was analyzed by the surface electric and charge distribution. Furthermore, the SERS spectra of 4NBT in the metal nanoparticle-dielectric film system confirmed the necessity of hybrid plasmon mode in the generation of plasmonic hot electrons in the nanoparticle-film system. Because of the simple configuration and convenient fabrication of nanoparticle-film system, the work on this hybrid plasmon mode has a significant role in promoting the application of plasmonic hot electrons.