Iridium nanoparticles anchored WO3 nanocubes as an efficient photocatalyst for removal of refractory contaminants (crystal violet and methylene blue)
Iridium nanoparticles anchored WO3 nanocubes as an efficient photocatalyst for removal of refractory contaminants (crystal violet and methylene blue)
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DOI：
10.1016/j.cplett.2020.137285
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发表时间：
2020-04-16
影响因子：
2.8
通讯作者：
Muthuraj, V
中科院分区：
文献类型：
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作者：
Dhanalakshmi, M.;Prabavathi, S. Lakshmi;Muthuraj, V
采用一步水热法制备了一系列新型可见光驱动的Ir/WO_3纳米复合材料。采用粉末X射线衍射仪(XRD)、X射线光电子能谱(XPS)、能谱扫描电子显微镜(SEM-EDX)、透射电子显微镜(TEM)和紫外-可见漫反射光谱(UV-Vis DRS)技术对Ir/WO_3纳米复合材料进行了系统的表征。扫描电子显微镜和透射电子显微镜分析表明，制备的WO_3纳米粒子呈立方体结构，Ir纳米粒子锚定在WO_3表面。光学结果表明，吸收带边位于可见光区，WO_3、Ir/WO_3(1%)、Ir/WO_3(3%)和Ir/WO_3(5%)的带隙能分别为2.87、2.8、2.6和2.5 eV。EDX和XPS分析表明，Ir/WO_3纳米复合材料中只含有Ir、W和O元素。研究了Ir/WO_3纳米催化剂在可见光照射下对结晶紫(CV)和亚甲基蓝(MB)有机污染物的光催化降解。与纯WO_3和其他Ir/WO_3纳米复合材料相比，负载量为3%的Ir/WO_3催化剂对CV和MB的降解表现出更好的光催化效率。光催化活性的提高主要是由于Ir纳米粒子的存在阻止了光生电子空穴对的复合以及Ir纳米粒子与WO_3纳米立方体之间的协同成键作用。对Ir负载浓度、催化剂的影响、污染物的影响以及光催化剂的稳定性等因素进行了解释。此外，通过自由基捕获法确定了Ir/WO_3催化剂可能的光催化机理。这种新型的Ir/WO3纳米复合材料被证明是一种有效的有机污染物减排工具催化剂。
A series of novel visible light driven Iridium loaded WO3 (Ir/WO3) nanocomposites were successfully synthesized via single step hydrothermal process. The Ir/WO3 nanocomposites were systematically characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM) and UV-vis diffused reflectance spectra (UV-vis DRS) techniques. The WO3 nanocparticles were showed nanocubes-like structure and Ir NPs were anchored on surface of WO3 which was confirmed by SEM and TEM analysis. Optical result indicated that the absorption band edge is positioned in the visible region with band gap energy of WO3, Ir/WO3 (1%), Ir/ WO3 (3%) and Ir/WO3 (5%) was 2.87, 2.8, 2.6 and 2.5 eV, respectively. From EDX and XPS analysis, Ir/WO3 nanocomposite contains Ir, W and O elements only. The Ir/WO3 nanocatalysts have been utilized for the photodegradation of crystal violet (CV) and methylene blue (MB) organic pollutants under the visible light irradiation. Compared to pure WO3 and other Ir/WO3 nanocomposites, 3% loaded Ir/WO3 catalyst exhibited superior photocatalytic efficiency towards the degradation of CV and MB. The enhancement of photocatalytic activity was mainly due to the presence of Ir nanoparticles on the surface of WO3 nanocubes preventing the photogeneration electrons-holes pair recombination and the synergistic bonding interaction between Ir NPs and WO3 nanocubes. Various factors such as Ir loading concentration, effect of catalyst, effect of pollutants and stability of the photocatalyst were explained. Furthermore, the possible photocatalytic mechanism of Ir/WO3 catalyst was determined by radical trapping studies. This novel Ir/WO3 nanocomposite proved to an efficient tool catalyst for the organic contaminants abatements.