The BiVO:Ho-Yb upconverting phosphors have been synthesized by using the chemical co-precipitation method and optimized with 0.7 % Ho + 6 % Yb combination through frequency upconversion emission study. The synthesized phosphors have been characterized through XRD (X-Ray diffraction), FESEM (Field emission scanning electron microscopy), HR-TEM (High resolution- Transmission electron microscopy), UV–vis diffuse reflectance spectroscopy (DRS), Raman, and FT-IR (Fourier transform infrared spectroscopy). The XPS (X-ray photoelectron spectroscopy) analysis has been performed to study the elemental composition, chemical, and electronic states of the atoms present in the optimized sample. The specific surface area of the pure and optimized phosphors has been determined through BET (Brunauer-Emmett-Teller) analysis. From the XRD analysis, it is clear that on doping, the crystal structure of BiVO changes from monoclinic to tetragonal structure. The values of rate constants for the photocatalytic performance of the upconverting codoped and pure BiVO phosphors under the illumination with an artificial solar lamp for degradation of MB dye are found to be 0.00498 min and 0.00269 min, respectively. To verify these results, the same experiment has also been performed under the visible LED (Light-emitting diode) light illumination. This enhancement of ∼ 85 % in the rate constant of the photocatalytic performance ensured the utilization of the NIR portion of the light by the codoped BiVO phosphors through the frequency upconversion process. The material’s recycling photocatalysis experiment for three cycles has been performed to check its reusability. The upconversion emission and XRD analysis of the materials after photocatalysis have been performed. From this study, it is confirmed that the stability of the sample is better even after three cycles of photocatalytic dye degradation experiment.

中文翻译：

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Ho3+-Yb3+激活BiVO4上转换荧光粉的光催化活性


采用化学共沉淀法合成了 BiVO:Ho-Yb 上转换荧光粉，并通过上转换发射研究对 0.7% Ho + 6% Yb 组合进行了优化。合成的荧光粉通过 XRD（X 射线衍射）、FESEM（场发射扫描电子显微镜）、HR-TEM（高分辨率透射电子显微镜）、紫外可见漫反射光谱 (DRS)、拉曼和 FT 进行表征-IR（傅里叶变换红外光谱）。 XPS（X 射线光电子能谱）分析用于研究优化样品中原子的元素组成、化学和电子状态。纯且优化的荧光粉的比表面积已通过 BET (Brunauer-Emmett-Teller) 分析确定。从 XRD 分析可以清楚地看出，掺杂后，BiVO 的晶体结构从单斜晶系转变为四方晶系结构。在人造太阳灯照射下，上转换共掺杂和纯 BiVO 荧光粉降解 MB 染料的光催化性能速率常数值分别为 0.00498min 和 0.00269min。为了验证这些结果，还在可见LED（发光二极管）光照射下进行了相同的实验。光催化性能的速率常数提高了约 85%，确保了共掺杂 BiVO 荧光粉通过上变频过程对光的近红外部分的利用。该材料进行了三个循环的回收光催化实验，以检验其可重复使用性。对光催化后的材料进行了上转换发射和 XRD 分析。 本研究证实，即使经过三个循环的光催化染料降解实验，样品的稳定性也更好。