Sublattice Energy Cluster Construction for The Enhancement of NIR Photocatalytic Performance of LiYF₄: Tm@TiO₂

Abstract

In this work, a stratagem of improving the photocatalytic performance of TiO 2 under NIR irradiation was illustrated by the combination of TiO 2 with upconversion (UC) luminescent materials that present high intensity of UV band emission resulted from the sublattice energy clusters in tetragonal LiYF 4 : Tm UC matrix. The sublattice energy clusters were constructed by doping high concentration Yb 3 + into tetragonal LiYF 4 : Tm. 347 nm emission intensity of Tm 3 + were enhanced dramatically with the rising of Yb 3 + doping concentration and reached the top while 70% Yb 3 + was doped, and the intensity was enhanced about 6.15 times compared with that of the usual 20% Yb 3 + doped. After being coated with TiO 2 , the photocatalytic performance of the complex was enhanced about 2.55 folds compared to P25. XRD, SEM, TEM, FTIR, UV-vis and fluorescence spectrum were employed for the systematical investigation of the relationship between structure and performance. This stratagem may be helpful for the design and preparation of photocatalysts and photo sensors.[a] Y.

Enhancement of Upconversion Luminescence by the Construction of a 3Yb-Er-Hf Sublattice Energy Cluster and Surface Defect Elimination

“…Rare-earth (RE)-doped upconversion luminescence nanoparticles (UCLNPs) are an important kind of functional nanomaterial. − They exhibit excellent performance and have evoked much attention due to their wide promising applications in temperature sensors, − solar energy conversion, , biomedical imaging, − biomass detection, medical tracers, , photodynamic therapy, ,, drug-targeted delivery, photocatalysis, , anticounterfeiting, , etc. Nano NaYF 4 :RE is an outstanding representative of these nanomaterials, , although the relatively poor UCL performance is still the main obstacle for their application.…”

Study on the Upconversion Luminescence Mechanism of Tegtragonal LiYF4: RE with Sublattice Energy Cluster Construction and Crystal Field Manipulation

“…In this work, the UCL mechanism of sublattice energy cluster construction and crystal field manipulation were revealed that may be an inspiration for high efficient UC luminescence materials design and preparation. Keywords LiYF 4 ; rare earth; sublattice structure; crystal field manipulation; upconversion luminescence 1 引言 稀土离子具有丰富的不饱和 4f 层核外电子能级结 构, 在长波光源激发下可实现反斯托克的短波光发射 [1] , 具有发射光波长分布范围广、发射谱带宽以及发射波长 可调控等优良特性, 使得稀土上转换发光材料在防 伪 [2][3][4] 、生物检测 [5,6] 、高分辨成像 [7][8][9] 、光动力治疗 [10,11] 、 药物靶向释放 [12,13] 、能源转换 [14,15] 、光催化 [16][17][18] 、光解 水 [19][20][21] 、光电器件 [22][23][24][25] 、温度传感器 [26,27] 等领域有着广 阔的潜在应用前景 [28] , 其成为近年发光材料领域研究 的热点 [29] . 当前限制稀土上转换发光材料应用的主要 瓶颈是可控发射波长、足够强的荧光强度和满足应用要 求的荧光寿命等上转换发光性能.…”