The interaction between plasmons in metal nanostructures and excitons in layered materials attracts recent interests due to its fascinating properties inherited from the two constituents, e.g., the high tunability on its spectral or spatial properties from the plasmonic component, and the large optical nonlinearity or light emitting properties from the excitonic counterpart. Here, we demonstrate light-emitting plexcitons from the coupling between the neutral excitons in monolayer WSe and highly confined nanocavity plasmons in the nanocube-over-mirror system. We observe, simultaneously, an anticrossing dispersion curve of the hybrid system in the dark-field scattering spectrum and a 1700 times enhancement in the photoluminescence. We attribute the large photoluminescence enhancement to the increased local density of states by both the plasmonic and excitonic constituents in the intermediate coupling regime. In addition, increasing the confinement of the hybrid systems is achieved by shrinking down the size of the hot spot within the gap between the nanocube and the metal film. Numerical calculations reproduce the experimental observations and provide the effective number of excitons taking part in the interaction. This highly compact system provides a room temperature testing platform for quantum cavity electromagnetics at the deep subwavelength scale.

The recent developments of analytical memristive mechanisms and simulation methods/tools for different structures and materials have been reviewed.

Owing to its 100% theoretical salt rejection capability, membrane distillation (MD) has emerged as a promising seawater desalination approach to address freshwater scarcity. Ideal MD requires high vapor permeate flux established by cross-membrane temperature gradient (∆T) and excellent membrane durability. However, it’s difficult to maintain constant ∆T owing to inherent heat loss at feedwater side resulting from continuous water-to-vapor transition and prevent wetting transition-induced membrane fouling and scaling. Here, we develop a Ti3C2Tx MXene-engineered membrane that imparts efficient localized photothermal effect and strong water-repellency, achieving significant boost in freshwater production rate and stability. In addition to photothermal effect that circumvents heat loss, high electrically conductive Ti3C2Tx MXene also allows for self-assembly of uniform hierarchical polymeric nanospheres on its surface via electrostatic spraying, transforming intrinsic hydrophilicity into superhydrophobicity. This interfacial engineering renders energy-efficient and hypersaline-stable photothermal membrane distillation with a high water production rate under one sun irradiation.

The fact that metallic nanostructures are an excellent light receiver and transmitter connects the underlying principles of two widely applied optical processes: surface-enhanced Raman scattering (SERS) and surface-enhanced fluorescence (SEF). A comparative study of SERS and SEF can eliminate the typical unknown quantities of the system and reveal important parameters that cannot be accessed by conventional techniques. Here, we use this simultaneous SERS and SEF technique in a monolayer MoSe 2 coupled plasmonic nanocavity. After optimizing the spatial and the spectral overlaps between excitonic and plasmonic resonances, the SERS and SEF enhancement factors can exceed 10 7 and 6000, respectively, at the same time on the same nanocube. The comparison of the SERS and SEF enhancements allows the estimation of the ultrafast total decay rate of the bright exciton in monolayer MoSe 2 in the nanocavity down to tens of femtoseconds, which is otherwise hard to realize using time-resolved techniques.

The axially chiral tetra-ortho-substituted biaryl skeleton exists in numerous biologically important natural products, pharmaceutical molecules, chiral catalysts, and ligands. The efficient synthesis of chiral tetra-ortho-substituted biaryl structures remains a challenging but unsolved problem. Among various asymmetric synthetic protocols, enantioselective Suzuki-Miyaura cross-coupling represents one of the most straightforward and versatile approaches. Herein we describe a powerful Suzuki-Miyaura coupling enabled by a P-chiral monophosphorus ligand BaryPhos, providing a broad range of synthetically challenging chiral tetra-ortho-substituted biaryls in excellent enantioselectivities and yields. In addition to the enhanced reactivity for sterically hindered cross-coupling, the rational design of BaryPhos also enabled a new catalysis mode of asymmetric cross-coupling involving noncovalent interactions between the ligand and two coupling partners to effect efficient stereoinduction. This protocol is robust and practical, allowing for a concise enantioselective synthesis of therapeutically valuable male contraceptive and antitumor agent gossypol.