Noble metal nanostructures are currently of great interest for their unique plasmonic property and potential applications in catalysis and surface-enhanced spectroscopy. However, the application of plasmonic nanostructures for quantitatively in situ SERS monitoring of the catalytic reaction has been a great challenge for investigators because combining plasmonics with catalysis requires the same kind of noble metal nanoparticles (NPs) in two very different size regimes. Herein, We have demonstrated a facile wet chemical method to synthesize Au-Ag alloy plasmonic NPs that could combine the desired plasmonic and catalytic properties with same NPs. The catalytic activity of Au-Ag alloy NPs using the reduction of 4-nitrothiophenol (4-NTP) by sodium borohydride (NaBH 4) is chosen as a model reaction. The signals of the reaction processes are detected and identified through in situ SERS spectroscopy with high sensitivity. The insights gained by current study may serve as a promising and powerful technique for better investigation in the heterogeneous catalysis. Moreover, the reduction of aromatic nitro compounds with prepared Au-Ag alloy NPs also provides potential application in sewage treatment.

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The UC fluorescence emission and tuning from Ce3+ codoped β-NaY(Gd0.4)F4:Yb3+/Ho3+ nanocrystals.

Rare earth ion-doped upconversion materials show great potential applications in optical and optoelectronic devices due to their novel optical properties.

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Optical transitions of Eu(3+)-doped LaOF nanocrystals with tetragonal and rhombohedral structures were studied experimentally using laser spectroscopic method. Fluorescence emissions from 5D1 and 5D0 of Eu3+ in LaOF nanocrystals were detected by exciting the sample with a 532 nm pulsed laser, and the influence of local symmetry on the fluorescence emission of doped ions was observed. The specific crystalline phase as well as the local symmetry on the fluorescence emission was investigated in both the frequency domain and time domain. It was found that Eu3+ ions doped in the tetragonal crystal structure present more efficient fluorescence emission, which was explained by lower symmetric distribution of local field at the doped ions.

In this work, we report a much simple and low-cost method to prepare main-chain-type semifluorinated alternating copolymers by the formation of halogen bond (XB) complex between α,ω-diiodoperfluoroalkanes and amines/halide salts....