Gautam Neelam, Singh Kijay Bahadur, Upadhyay Deen Dayal, Pandey Gajanan
Department of Chemistry, Babasaheb Bhimrao Ambedkar University Lucknow India
RSC Adv. 2023 Aug 1;13(33):23181-23196. doi: 10.1039/d3ra03315e. eCollection 2023 Jul 26.
In recent decades, several nanocomposites developed by chemical synthetic routes, have been demonstrated as efficient photocatalysts for the photodegradation of hazardous organic dyes. The present investigation reports the sonochemical-assisted fabrication of silver-supported α-FeO nanocomposites (SA@Ag@IONCs) using the leaf extract. The magnetic nanocomposites can be easily removed from the reaction mixture. The morphology of these materials was characterized by field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), XPS, BET surface area analyzer, UV-visible spectroscopy, photoluminescence, X-ray diffraction (XRD), and VSM techniques. The XRD and electron microscopy analyses revealed the small size and well-crystalline SA@Ag@IONC particles with spherical and buckyball structures. The large surface area of SA@Ag@IONCs was confirmed by BET analysis. The absorption edge in UV-visible spectra appeared to migrate towards high wavelengths for the SA@Ag@IONC composite, causing a change in the bandgap energy. In the case of the sonication assisted composite, the bandgap energy was 2.1 eV, making it easier for the electron to transfer from the valence band to conduction band. The decoration of ultrasmall silver onto the surfaces of the α-FeO nanocomposite, which considerably increases the capacity to absorb sunlight, enhances the efficiency of charge carrier separation, and inhibits the electron-hole recombination rate as confirmed by the reduced PL intensity, is responsible for the excellent photocatalytic degradation performance. Outcomes shown SA@Ag@IONCs have a high photodegradation rate as well as high-rate constant value at an optimized condition that is at pH 9 and 0.5 g L dose of nanocomposite, photodegradation rate of Azure B is ∼94%. Trap experiment results indicated that O˙ and h are the active species responsible for the photodegradation of AzB.
近几十年来，通过化学合成路线开发的几种纳米复合材料已被证明是用于光降解有害有机染料的高效光催化剂。本研究报道了利用叶提取物通过声化学辅助制备银负载的α-FeO纳米复合材料（SA@Ag@IONCs）。磁性纳米复合材料可以很容易地从反应混合物中分离出来。通过场发射扫描电子显微镜（FESEM）、高分辨率透射电子显微镜（HRTEM）、XPS、BET表面积分析仪、紫外可见光谱、光致发光、X射线衍射（XRD）和VSM技术对这些材料的形貌进行了表征。XRD和电子显微镜分析表明，SA@Ag@IONC颗粒尺寸小且结晶良好，具有球形和巴基球结构。BET分析证实了SA@Ag@IONCs具有较大的表面积。SA@Ag@IONC复合材料的紫外可见光谱中的吸收边似乎向高波长方向移动，导致带隙能量发生变化。在超声辅助复合材料的情况下，带隙能量为2.1 eV，这使得电子更容易从价带转移到导带。超小银在α-FeO纳米复合材料表面的修饰大大提高了吸收太阳光的能力，增强了电荷载流子分离效率，并通过降低的PL强度证实抑制了电子-空穴复合率，这是其优异光催化降解性能的原因。结果表明，在pH为9和纳米复合材料剂量为0.5 g/L的优化条件下，SA@Ag@IONCs具有高光降解率和高反应速率常数，天青B的光降解率约为94%。捕获实验结果表明，O˙和h是负责光降解AzB的活性物种。
