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Porous covalent organic frameworks (COFs) have been widely used for the efficient removal of iodine from solution due to their abundance of electron-rich sites. In this study, two kinds of ketoenamine-based COFs, TpBD-(OMe)2 and TpBD-Me2, are successfully synthesized via Schiff base reaction under solvothermal conditions using 1, 3, 5-triformylphoroglucinol as aldehyde monomer, o-tolidine and o-dianisidine as amino monomers. The ability of TpBD-(OMe)2 and TpBD-Me2 to adsorb iodine in cyclohexane or aqueous solutions has been quantitatively analyzed and interpreted in terms of adsorption sites. TpBD-Me2 possesses two adsorption sites, -NH- and -C=O, and exhibits an adsorption capacity of 681.67 mg/g in cyclohexane, with an initial adsorption rate of 0.6 g/mol/min with respect to COF unit cell. The adsorption capacity of TpBD-(OMe)2 can be as high as 728.77 mg/g, and the initial adsorption rate of TpBD-(OMe)2 can reach 1.2 g/mol/min in the presence of oxygen atoms between the methyl group and the benzene ring. Compared with TpBD-Me2, the higher adsorption capacity and adsorption rate of TpBD-(OMe)2 towards iodine are not only reflected in organic solvents, but also in aqueous solutions. It is proven through X-ray photoelectron spectroscopy and Raman spectroscopy that iodine exists in the form of I2, I3−, and I5− within TpBD-(OMe)2 and TpBD-Me2 after adsorption. This work not only expands the application of COFs in the field of iodine adsorption, but also provides research ideas and important an experimental basis for the optimization of iodine adsorption sites. [ABSTRACT FROM AUTHOR]

LaScO3:xBi3+,yTb3+,zEu3+ (x = 0 − 0.04, y = 0 − 0.05, z = 0 − 0.05) phosphors were prepared via high‐temperature solid‐state reaction. Phase identification and crystal structures of the LaScO3:xBi3+,yTb3+,zEu3+ phosphors were investigated by X‐ray diffraction (XRD). Crystal structure of phosphors was analyzed by Rietveld refinement and transmission electron microscopy (TEM). The luminescent performance of these trichromatic phosphors is investigated by diffuse reflection spectra and photoluminescence. The phenomenon of energy transfer from Bi3+ and Tb3+ to Eu3+ in LaScO3:xBi3+,yTb3+,zEu3+ phosphors was investigated. By changing the ratio of x, y, and z, trichromatic can be obtained in the LaScO3 host, including red, green, and blue emission with peak centered at 613, 544, and 428 nm, respectively. Therefore, two kinds of white light‐emitting phosphors were obtained, LaScO3:0.02Bi3+,0.05Tb3+,zEu3+ and LaScO3:0.02Bi3+,0.03Eu3+,yTb3+. The energy transfer was characterized by decay times of the LaScO3:xBi3+, yTb3+, zEu3+ phosphors. Moreover absolute internal QY and CIE chromatic coordinates are shown. The potential optical thermometry application of LaScO3:Bi3+,Eu3+ was based on the temperature sensitivity of the fluorescence intensity ratio (FIR). The maximum Sa and Sr are 0.118 K−1 (at 473.15 K) and 0.795% K−1 (at 448.15 K), respectively. Hence, the LaScO3:Bi3+,Eu3+ phosphor is a good material for optical temperature sensing. [ABSTRACT FROM AUTHOR]

A series of Cs2BF6:Mn4+ (B = Ge, Si, Ti, Zr) red phosphors were synthesized by a precipitation‐cation exchange route. The phase purity, morphology, and constituent were characterized by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). Optical properties were investigated by photoluminescence (PL) spectra and high‐resolution PL. Temperature‐dependent PL examination at the range of both 273‐573 K and 10‐300 K was performed to investigate the emission mechanism of Mn4+ in these fluorides. The intensity for both zero‐phonon lines (ZPLs) and vibration coupled emission of Mn4+ in these four systems with different crystal structures was investigated systematically. These phosphors present bright red emission under blue light (467 nm) illumination, among which Cs2GeF6:0.1Mn4+ shows the highest emission intensity with ultrahigh quantum efficiency of 94%. The white light‐emitting diodes (WLEDs) fabricated with this sample, blue InGaN chips and commercial YAG:Ce3+ phosphor exhibited high luminous efficacy beyond 100 lm/w with high color rendering index (~88.6) and low color temperature (~3684 K). [ABSTRACT FROM AUTHOR]