Effect of L-Cysteine on Photoluminescence of Zns:F Quantum Dots

Abstract

ZnS:F quantum dots (QDs) capping with and without L-cys were synthesized by a solid-state method at low temperature, and the influence of L-cys on the properties of ZnS:F QDs were investigated. The crystal structure, surface morphology and luminescent properties of the samples were analyzed by X-ray diffractometer (XRD), transmission electron microscope (TEM), fourier transform infrared (FTIR), photoluminescence spectrometer (PL) and ultraviolet-visible spectrometer (UV-Vis). The results showed that all samples had a zinc blende structure with particle size in the range of 2-6 nm. The emission intensity was significantly enhanced after capping with L-cys, and the strongest luminescence was obtained when the ratio of L-cys/ZnS:F was 0.8:1, and was about 2.5 times of that of ZnS:F QDs. The capping of L-cys increased the grain size of ZnS:F QDs and their water solubility.

Mild Liquid Phase Oxidation of Benzyl Alcohol in the Presence of Microporous Framework Copper Silicates

“…Using hydrothermal techniques, it is possible to obtain a series of zeotype microporous copper silicates, known as CuSH-nA where n is the framework type number, and A indicates the extra-framework cations. [24] The phases CuSH-1, CuSH-2 and CuSH-3 were first described in 2002. [24][25][26] In particular, CuSH-1A (A = Na, K, Rb, Cs) possess a one-dimensional 12ring channel system with alkali cations to compensate framework negative charges and alkali hydroxides to stabilize the structure (Figure 1a).…”

“…[24] The phases CuSH-1, CuSH-2 and CuSH-3 were first described in 2002. [24][25][26] In particular, CuSH-1A (A = Na, K, Rb, Cs) possess a one-dimensional 12ring channel system with alkali cations to compensate framework negative charges and alkali hydroxides to stabilize the structure (Figure 1a). [27,28] In 2015, a copper silicate SGU-29 was described as a two-dimensional 12-ring channel system ( Figure 1b), possessing a very similar structure to the titanosilicate ETS-10.…”