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Despite many Eu2+‐doped phosphors having been synthesized by different methods, a simple synthetic strategy for Eu2+‐doped high‐performance phosphors remains one of the significant challenges for phosphor‐conversion white light‐emitting diodes. Herein, a novel broad‐band excitation yellow phosphor Ba0.985Al4Sb2O12:0.015Eu2+ (BASO:Eu2+) with high thermal stability (423 K, 94%) and internal quantum efficiency (96.7%) are reported. More importantly, the novel phosphor is synthesized by solid‐state reaction at high temperatures in air. Structural and spectral analyses show that the Eu2+ ions in BASO preferably occupy [BaO8] hexahedra, forming a single luminescence center. This study provides a reliable direction for the facile synthesis of high‐performance Eu2+‐doped phosphors in air.

Exploring cost-effective catalysts with high catalytic performance and long-term stability has always been a general concern for environment protection and energy conversion. Here, Au nanoparticles (NPs) embedded CuO x-CeO 2 core/shell nanospheres (Au@CuO x-CeO 2 CSNs) have been successfully prepared through a versatile one-pot method at ambient conditions. The spontaneous auto-redox reaction between HAuCl 4 and Ce(OH) 3 in aqueous solution triggered the self-assembly growth of micro-/ nanostructural Au@CuO x-CeO 2 CSNs. Meanwhile, the CuO x clusters in Au@CuO x-CeO 2 CSNs are capable of improving the anti-sintering ability of Au NPs and providing synergistic catalysis benefits. As a result, the confined Au NPs exhibited extraordinary thermal stability even at a harsh thermal condition up to 700 C. In addition, before and after the severe calcination process, Au@CuO x-CeO 2 CSNs can exhibit enhanced catalytic activity and excellent recyclability towards the hydrogenation of p-nitrophenol compared to previously reported nanocatalysts. The synergistic catalysis path between Au/CuO x /CeO 2 triphasic interfaces was revealed by density functional theory (DFT) calculations. The CuO x clusters around the embedded Au NPs can provide moderate adsorption strength of p-nitrophenol, while the adjacent CeO 2-supported Au NPs can facilitate the hydrogen dissociation to form H* species, which contributes to achieve the efficient reduction of p-nitrophenol. This study opens up new possibilities for developing high-efficient and sintering-resistant micro-/nanostructural nanocatalysts by exploiting multiphasic systems.

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Polarized emission, an inherent characteristic that correlated with structure and morphology, is very sensitive to orientation. For the upconversion (UC) emission of lanthanides, the mechanism of polarization is rarely discussed, and the highly polarized UC emissions are poorly developed. Herein, with the benefit of the strong anisotropic crystal field, well-resolved emissions from lanthanide-doped LiYF 4 crystals were studied, and highly polarized UC emissions from Er 3+ and Ho 3+ were investigated. With multiple sub-energy level transitions, the UC emissions are classified into two sets, with transition dipoles being either parallel or perpendicular to the c-axis of the LiYF 4 crystal. An optical three-dimensional orientation sensor was further investigated, in which the in-plane angle is referenced from the orientation of the transition dipoles. In contrast, the out-of-plane angle can be deduced from the change in the degree of polarization. This research deepens our understanding of the polarized photoluminescence, and it opens up an avenue toward unique UC orientation sensors.

A novel apatite‐type SrMgY3(SiO4)3F was synthesized by a high‐temperature solid‐state reaction. The crystal structure was refined using powder X‐ray diffraction data. SrMgY3(SiO4)3F crystallizes in P63/m hexagonal space group with lattice parameters of a = b = 9.45270 Å, c = 6.77617 Å, and V = 524.357 Å3. The incorporation of the Ce3+ and Tb3+ ions into the matrix can generate bright blue and green lights under ultraviolet (UV) light excitation. The codoped Ce3+ and Tb3+ in SrMgY3(SiO4)3F can effectively improve green emission intensity and thermal stability through the energy transfer from the Ce3+ to Tb3+ ions. With the increase of Tb3+‐doping content, the luminescent color of phosphor changes from blue to cyan and finally to green. SrMgY3(SiO4)3F:0.06Ce3+,0.90Tb3+ phosphor exhibited intense green light emission with a quantum yield of 59.49% and good thermal stability, with an emission intensity at 150°C was 96% of that at 30°C. Finally, the prepared sample was coated on 365 nm UV chips to fabricate white light‐emitting diodes with a color rendering index of 82.6 and a correlated color temperature of 2912 K, demonstrating its potential for applications in display and lighting.

It is of significant importance to tailor the luminescent properties of Cr3+ ions as efficient near‐infrared (NIR) emitter for extended optical applications. Here, crystal field engineering is explored to tailor the luminescent properties of a Cr3+‐doped garnet, Lu2Ca1 ‐ xSrxAl4SiO12 (x = 0–1). As Ca2+ is substituted by Sr2+, the emission of Cr3+ becomes sharper with longer lifetime, indicating that the 2Eg→4A2g transition becomes dominant. More importantly, the thermal stability is greatly improved, as the emission intensity at 480 K increases from 83% to 111% of that at 300 K. Moreover, the efficiency of the energy transfer from the Cr3+ to Yb3+/Nd3+ increases from 60–70% to 80–90%. The intensity ratio of I810/I706 from the Lu2SrAl4SiO12:Cr3+,Nd3+ can be applied to thermometry, with the maximum relative sensitivity value of 1.43% K–1 at 303 K. Compared with the blue emission from light‐emitting diode (LED) chip, a clearer and more accurate imaging is established with NIR emission from Cr3+. Furthermore, the intensity ratio of the emissions from the Cr3+ and Yb3+ ions is applied to differentiate pork, chicken, and beef. These findings provide an avenue to optimize the thermal stability and energy transfer of Cr3+‐activated NIR emitters for the applications in thermometry and NIR‐LED.