Electron transition manipulation under graphene-mediated plasmonic engineering nanostructure

Monolayer graphene has attracted enormous attention owing to its unique electronic and optical properties.However,achieving an effective approach without applying electrical bias for manipulating the charge transfer based on graphene is elusive to date.Herein,we realized the manipulation of excitons’transition from emitter to the graphene surface with plasmonic engineering nanostructures and firstly obtained large enhancements for photon emission on the graphene surface.The localized plasmons generated from the plasmonic nanostructures of shell-isolated nanoparticle coupling to ultra-flat Au substrate would dictate a consistent junction geometry while enhancing the optical field and dominating the electron transition pathways,which may cause obvious perturbations for molecular radiation behaviors.Additionally,the three-dimensional finite-difference time-domain and time-dependent density functional theory were also carried out to simulate the distributions of electromagnetic field and energy levels of hybrid nanostructure respectively and the results agreed well with the experimental data.Therefore,this work paves a novel approach for tunning graphene charge/energy transfer processes,which may hold great potential for applications in photonic devices based on graphene.

Plasmonic photocatalysis:Mechanism,applications and perspectives

The process of photocatalysis,regarded as a promising approach for tackling the energy crisis and environmental pollution issues,is crucial for turning solar light into chemical resources.However,the solar-chemical conversion efficiency of typical semiconductor catalysts is still too low,so it is vital to figure out how to boost photocatalytic performance of semiconductors.Under visible light illumination,the local surface plasmon resonance(LSPR)induced by coinage metal would enhance the local electric field and improve photocatalytic performance of semiconductors,especially in the visible range.Therefore,its attachment to semiconductors has been regarded as an efficient strategy to improve photocatalytic performance.This paper reviews the latest research progress of plasmonic photocatalysis from theory to application.Starting from the excitation and relaxation of plasmons,four main mechanisms of plasmon-enhanced semiconductor photocatalysis are introduced,including enhanced light absorption and scattering,local electromagnetic field enhancement,improved hot carriers(HCs)injection and enhanced thermal effect.Secondly,the current mainstream plasmonic photocatalysts,such as monometallic,bimetallic and non-noble metal-based plasmonic catalysts,are reviewed.Finally,the applications of plasmonic photocatalysts in H_(2) production,CO_(2) reduction,and antibacterial are further summarized.