Fluorinated graphene films for Ultra-High sensitivity of Surface-Enhanced Raman scattering

Diffusion Behavior of Iodine in the Micro/Nano-Porous Graphite for Nuclear Reactor at High Temperature

“…D band strength I D of graphite depends on the defect type and density. The strength ratio (I D /I G ) of D band and G band are used to evaluate the grain size and graphitization degree [17]. Based on the integral area ratio between the D band and the G band intensities, called I D and I G , respectively.…”

Near-Neighbor Electron Orbital Coupling Effect of Single-Atomic-Layer Au Cluster Intercalated Bilayer 2H-TaS2 for Surface Enhanced Raman Scattering Sensing

“…Owing to their unusual properties, two-dimensional (2D) materials and corresponding doping systems have been proven to be one of the most promising candidates for numerous potential applications like electronics, optoelectronics, catalysis, energy storage, biomedicine, environments, etc. And, by virtue of advantages such as outstanding fluorescence quenching capability, excellent biomolecular compatibility, tunable Fermi levels, and potentially low-cost material preparation, 2D materials could potentially be considered as ideal metal-free surface-enhanced Raman scattering (SERS) materials. − However, such materials enhance Raman signals via the chemical mechanism (CM), and usually suffer from limited Raman enhancement factors (EFs) (typically below 10 3 ), as compared with metallic materials. , To achieve the goal of high SERS performance, the hybrid metallic NPs-2D materials, or chemically doped 2D materials system and their SERS enhancement mechanisms, are enormously studied. ,− For the composite structure of noble metal nanoparticles (NPs) or nanorods (NRs) with 2D materials, the SERS enhancement mechanism is the synergistic effect of electromagnetic field enhancement provided by precious metal particles and chemical enhancement caused by charge transfer between 2D materials and probe molecules. ,, In the system of 2D materials treated with chemical doping or oxygen plasma, researchers believe that the enhancement mechanism is that different atomic doping or defect introduction will change the energy band position of the system, making it more compatible with the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the probe molecule, improving the efficiency of charge transfer. ,,− Compared with a two-dimensional semiconductor (e.g., MoS 2 , WS 2 ), semimetallic and quasi-metallic materials have relatively high surface activity and large density of states (DOS) near the Fermi level, ,, which means that they can provide strong analyte–SERS material coupling and effective charge transfer; on the other hand, a large number of electrons above the Fermi surface may interact with the laser to form strong local plasmons and may become ideal 2D SERS materials.…”