Tunable white light emission by variation of composition and defects of electrospun Al₂O₃–SiO₂ nanofibers

Abstract

SummaryComposite nanofibers consisting of Al2O3–SiO2 were prepared by electrospinning in combination with post-calcination in air. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were used to investigate the crystalline phase and microstructure of the composite nanofibers. Photoluminescence experiments indicated that the resulting white light emission can be tuned by the relative intensity of the individual spectral components, which are related to the individual defects such as: violet-blue emission from O defects, green emission from ≡Si(Al)–O–C∙=O, and red emission from intersystem radiative crossing. White light emission was realized at a Al/(Al–Si) ratio of 40 and 60 mol %. This research may offer a deeper understanding of the preparation of efficient and environmentally friendly, white luminescence materials.

An Insight into the Various Defects-Induced Emission in MgAl2O4 and Their Tunability with Phase Behavior: Combined Experimental and Theoretical Approach

“…To correlate the oxygen vacancy (OV) with the emission behavior, the compound was further annealed under vacuum atmosphere. Earlier reports on different matrixes showed that a change in the metal ion’s composition ratio may lead to a change in the PL behavior . In the present case, to investigate any change in the PL behavior, we have slightly changed the ratio such as and from that ideal 1 / 2 ratio in the pure spinel.…”

“…Earlier reports on different matrixes showed that a change in the metal ion's composition ratio may lead to a change in the PL behavior. 35 In the present case, to investigate any change in the PL behavior, we have slightly changed the Mg Al ratio such as 0.98 2 and 1 1.96 from that ideal 1 / 2 ratio in the pure spinel. Large variation of the Mg Al ratio from the ideal ratio may lead to formation of binary systems such as MgO−Al 2 O 3 composite or a mixture consists of several phases such as MgAl 2 O 4 , MgO, Al 2 O 3 , and so on.…”

CO2 Capture Performance of Mesoporous Synthetic Sorbent Fabricated Using Carbide Slag under Realistic Calcium Looping Conditions

“…The phenomenon indicates that the binding energy and stability of the functional group, Al–O, become greater, which is consistent with the result reported by Madroñero et al Besides the fact that the bands around 690 cm –1 of synthetic sorbents are assigned to the Al–O bond, it can be seen that the depth of the bands becomes more pronounced as the high alumina cement content increases, which indicates that C 12 A 7 content increases with the increase of the high alumina cement. The band located at 1120 cm –1 is speculated to be caused by two factors: one is attributed to O–Si–O bending of the SiO 4– group; the other indicates the formation of the Al–O–Si bond. , These vibrational modes appear at frequencies relatively close to each other due to the similar mass of Si and Al atoms. The existence of SiO 4– is probably due to a minor constituent of SiO 2 in carbide slag.…”

“…The band located at 1120 cm −1 is speculated to be caused by two factors: one is attributed to O−Si−O bending of the SiO 4− group; the other indicates the formation of the Al− O−Si bond. 50,51 These vibrational modes appear at frequencies relatively close to each other due to the similar mass of Si and Al atoms. The existence of SiO 4− is probably due to a minor constituent of SiO 2 in carbide slag.…”

Production of Nanostructured Aluminosilicate Fibers from Poly(ethylene glycol) Based Electrospun Fibers

“…The obtained nanofibers were heat‐treated at 1200 °C in the air to remove polymer and to produce mullite and cristobalite nanocrystals. The experiments indicated that the prepared materials could be used as catalysts, coatings, and microelectronics devices . Su et al synthesized aluminosilicate nanotubes by combining the sol‐gel method with electrospinning of a PVA solution.…”