Near‐Infrared Broadband Photoluminescence of Bismuth‐Doped Zeolite‐Derived Silica Glass Prepared by SPS

Abstract

Through the order–disorder transition process of zeolites, bismuth‐doped zeolite‐derived silica glasses with broadband near‐infrared (NIR) photoluminescence have been successfully prepared by spark plasma sintering (SPS). The samples were characterized by X‐ray diffraction, UV‐vis, photoluminescence, and fluorescence lifetime. The results showed that as‐prepared samples possessed favorable broadband NIR luminescence. The NIR emission (peaked at ~1140 nm) intensity decreased with increasing the bismuth doping concentration when excited by 500 and 700 nm. The tendency was different from the emissions (peaked at ~1240 nm) excited by 800 nm. In addition, the NIR fluorescence peaks of the fixed Bi concentration sample can be observed almost around 1140 or 1240 nm when excited by different wavelengths from 500 to 950 nm. These phenomena implied that the NIR emission peaked at different wavelengths may originate from different bismuth species. Three kinds of Bi active centers Bi+, Bi0, and (Bi2)2− were proposed to contribute to the NIR emission peaks at ~1140, 1240, and 1440 nm, respectively. Interestingly, a broadband NIR emission peaked at 1207 nm with a full‐width at half maximum of 273 nm was observed when excited by 600 nm, whose intensity was stronger than that excited by 800 nm. This property might be useful for broadband fiber amplifiers and tunable lasers.

Controllable synthesis of glass ceramics containing YF3:Eu3+ nanocrystals: Well‐preserved Eu and prolonged lifetime

“…The corresponding XRD patterns in Figure 1B present a characteristic hump at ~23° with no sharp peaks from silica crystals, revealing the formation of amorphous silica glass without crystallization. However, as the content of YF 3 :Eu 3+ NCs is below 2.7 vol%, which is lower than the detection limit of XRD, the similar phenomenon has been reported by other researchers, 28 and the characteristic peaks of YF 3 :Eu 3+ NCs are close to those of silica, which may be easily covered. The diffraction peaks of YF 3 :Eu 3+ NCs could not be clearly detected even when the concentration of YF 3 :Eu 3+ NCs reaches up to 5 wt%.…”

Silica foams with ultra‐large specific surface area structured by hollow mesoporous silica spheres

“…Inspired by the rapid development of inorganic mesoporous spheres, we propose to fabricate ceramic foam materials, employing hollow spheres as building blocks, which have been demonstrated to be a kind of promising raw materials to prepare bulk materials . In this paper, we utilize hollow silica mesoporous spheres (short for HMSSs) to fabricate novel foam materials constituted by three dimensional HMSSs‐assembled network, using particle‐stabilized foaming method which is recognized as an eco‐friendly as well as convenient method to prepare ceramic foams with high porosity and uniform pore structure .…”

Large‐sized La2O3‐TiO2 high refractive glasses with low SiO2 fraction by hot‐press sintering

“…Jiangtao Li et al obtained Y 2 O 3 ‐Al 2 O 3 ‐SiO 2 , Al 2 O 3 ‐La 2 O 3 ‐ZrO 2 , HfO 2 ‐Al 2 O 3 ‐Y 2 O 3 amorphous host materials by a similar method. In addition, there are some interesting reports about optical glasses via spark plasma sintering (SPS) . However, there is no report about the large‐sized La 2 O 3 ‐TiO 2 system high‐refractive bulk glass.…”