Plasmonic systems based on metal nanoparticles on a metal film have generated great interest for surface-enhanced Raman spectroscopy (SERS) chemical sensors. In this study, we describe the fabrication of ultrasensitive SERS substrates based on high-density gold nanostar assemblies on silver films with tailored surface plasmons, where multiple field enhancements from particle-film and interparticle plasmon couplings and lightening rod effects of sharp tips of nanostars contribute to the enormous Raman enhancements. We show that the interplay between interparticle and particle-film plasmon couplings of high-density gold nanostars (GNSs) on metal and dielectric films as a function of interparticle separation can be tailored to provide maximum SERS effects. We observe that the SERS enhancement factor (EF) of GNSs on a metal film as a function of interparticle separation follows a broken power law function, where the EF increases with the interparticle separation for the strong interparticle coupling range below an interparticle separation of ~0.8 times the GNS size, but decreases for the weak interparticle coupling range (for an interparticle separation of >0.8 times the GNS size). Finally, we demonstrate the use of tailored plasmonic substrates as ultrasensitive SERS chemical sensors with an attomole level of detection capability of 2,4-dinitrotoluene, a model compound of nitroaromatic explosives.

A PTMA-impregnated CNT electrode achieves the enhancement of discharge capacity, cycleability and rate capability of sodium batteries.

Ultralight and flexible perovskite solar cells with the orthogonal AgNW electrodes exhibit an excellent power-per-weight of 29.4 W g−1.

An aqueous Na-ion based hybrid capacitor has been successfully developed by highly porous graphitic carbon (HPGC) derived by waste writing paper and a new electrode material as negative and positive electrode, respectively. HPGC was prepared via hydrothermal carbonization and subsequent KOH activation of waste writing paper which showed highly porous stacked sheet like morphology with exceptionally high BET specific surface area (1254 m 2 g -1 ). HPGC exhibited typical electrical double layer capacitor (EDLC) behavior with a high specific capacitance of 384 F g -1 and good negative working potential (-1.0 V) in aqueous electrolyte. On the other hand, Ni2P2O7 was synthesized by simple co-precipitation technique and tested as cathode material which delivered a maximum specific capacitance of 1893 F g -1 at 2 A g -1 current density. The fabricated HPGC||Ni2P2O7 hybrid device displayed excellent cyclic stability up to 2000 cycles and delivered maximum energy density of 65 W h kg -1 at 800 W kg -1 power density in Na-ion based aqueous electrolyte.capacitive electrode by hemp carbonization and assembled