Reaction Kinetics, Mechanisms and Catalysis ( IF 1.7 ) Pub Date : 2021-08-17 , DOI: 10.1007/s11144-021-02051-3 Qiushi Xu 1 , Shielah Mavengere 1 , Jung-Sik Kim 1
|
CaAl2O4:Eu2+, Nd3+ phosphor was synthesized by a solid-state method at 1400 °C. The CaAl2O4:Eu2+, Nd3+ phosphor particles were coated by sol–gel dip coating method with a peroxo treated titanium hydroxide complex solution. The effect of peroxo treatment time and calcination temperatures was investigated in comparison with conventional TiO2-sol coated nanocomposites. Characterization of the CaAl2O4:Eu2+, Nd3+/TiO2 nanocomposites was conducted by X-ray diffraction, scanning electron microscopy, UV–Vis absorption spectra, and energy dispersive spectroscopy. The photocatalytic reactivity was evaluated by degradation of methylene blue aqueous solution under ultra-violet and visible light irradiations. CaAl2O4:Eu2+, Nd3+/TiO2 composite coated with peroxo titanium complex solution for 80 s showed the fastest photocatalytic reactivity under ultra violet and visible light illumination. Peroxo treatment for a long soaking time of 300 s effected etching of the phosphor surface and formation of CaTiO3 phases. With prolongation of the time of soaking the phosphor in the peroxo titanium complex solution to 300 s, the photocatalytic reactivity of the CaAl2O4:Eu2+, Nd3+/TiO2 composite decreased. In addition, composites displayed excellent photocatalytic under visible light irradiation, compared with pure TiO2. The acidity of the peroxo treatment, soaking time, and heat treatment conditions are important parameters for synthesizing photoactive nanocomposites for pollution control application.
Graphic abstract
CaAl2O4:Eu2+, Nd3+ was coated with peroxo treated TiO2-sol under different coating times. The peroxo treatment imparted acidic pH while longer soaking times resulted in etching of the phosphor surface. A wavy micro-ridge microstructure with dispersed clusters of TiO2 was dominant in the 300 s coated samples. The samples without peroxo treated (CTB) and 80 s coated samples were densely coated with TiO2 nanoparticles. The CaAl2O4:Eu2+, Nd3+/TiO2 samples coated in peroxo titania sol exhibited the most superior photocatalytic degradation of methylene blue aqueous solution under ultra-violet and visible light irradiations.
中文翻译：
过氧钛络合物溶液制备CaAl2O4:Eu2+、Nd3+/TiO2复合材料及其对亚甲蓝的光降解
CaAl 2 O 4 :Eu 2+ , Nd 3+荧光粉通过固态方法在1400°C下合成。CaAl 2 O 4 :Eu 2+ , Nd 3+荧光粉颗粒通过溶胶-凝胶浸涂法用过氧处理过的氢氧化钛络合物溶液进行涂覆。与传统的TiO 2溶胶涂覆的纳米复合材料相比，研究了过氧处理时间和煅烧温度的影响。CaAl 2 O 4 :Eu 2+ , Nd 3+ /TiO 2 的表征纳米复合材料通过 X 射线衍射、扫描电子显微镜、紫外-可见吸收光谱和能量色散光谱进行。通过在紫外线和可见光照射下降解亚甲基蓝水溶液来评估光催化反应性。CaAl 2 O 4 :Eu 2+ , Nd 3+ /TiO 2复合物涂覆过氧钛络合物溶液80 s在紫外和可见光照射下表现出最快的光催化反应。过氧处理 300 s 的长时间浸泡会影响磷光体表面的蚀刻和 CaTiO 3 的形成阶段。随着荧光粉在过氧钛络合物溶液中的浸泡时间延长至300 s，CaAl 2 O 4 :Eu 2+、Nd 3+ /TiO 2复合物的光催化反应活性降低。此外，与纯 TiO 2相比，复合材料在可见光照射下表现出优异的光催化性能。过氧化处理的酸度、浸泡时间和热处理条件是合成用于污染控制应用的光活性纳米复合材料的重要参数。
图形摘要
CaAl 2 O 4 :Eu 2+ , Nd 3+在不同的涂覆时间下用过氧化处理的TiO 2 -sol 涂覆。过氧化处理赋予酸性 pH 值，而较长的浸泡时间导致磷光体表面的蚀刻。在 300 秒的涂层样品中，具有分散的 TiO 2簇的波浪状微脊微结构占主导地位。未经过氧处理 (CTB) 和 80 秒涂层样品的样品被 TiO 2纳米颗粒致密地涂覆。CaAl 2 O 4 :Eu 2+ , Nd 3+ /TiO 2 涂有过氧化钛溶胶的样品在紫外线和可见光照射下表现出最优异的亚甲基蓝水溶液光催化降解。
京公网安备 11010802027423号