Department of Chemistry, College of Education, University of Al-Qadisiyah, Al Diwaniyah, Iraq.
Environ Sci Pollut Res Int. 2023 Feb;30(8):20775-20789. doi: 10.1007/s11356-022-23614-4. Epub 2022 Oct 18.
In this study, Ag-WO/bentonite nanocomposites were synthesized through a sol-gel process, a microwave irradiation technique, and a sol-immobilization process to examine their impact on the photocatalytic activity in the degradation of humic acids. The optical and structural properties of the synthesized materials were characterized using X-ray diffraction (XRD), Fourier-transform-infrared spectra (FTIR), field emission scanning electron microscope (FE-SEM) with energy dispersive X-ray (EDX), UV-Vis diffused reflectance spectra (UV-Vis DRS), Brunauer-Emmett-Teller (BET) method, and transmission electron microscope (TEM). The presence of Ag and WO peaks in the XRD and EDX spectra confirmed the synthesis of Ag-WO nanoparticles in the composite. The monoclinic structure of the produced WO samples are shown by powder X-ray diffraction patterns. The WO-based nanocomposites' photocatalytic activity was improved by the composition of Ag and bentonite, which reduced the optical bandgap energy of WO. The binary (Ag-WO) nanocomposite showed improved photocatalytic activity towards the degradation of humic acid (HA) from 58% (pristine WO3) to 82% (Ag-WO) when compared with the pristine WO3 sample under the visible light irradiation. Notably, the ternary (Ag-WO/bent) nanocomposite demonstrated an outstanding photocatalytic efficiency of HA degradation (91.0%) under normal conditions (pH = 7.0 and 25 °C). Humic acid degradation in Ag-WO/bent was expressed by the pseudo-first-order kinetic. To summarize, integrating Ag, WO, bentonite, and visible light radiation to activate HA efficiently can be offered as a successful and promising technique for wastewater treatment.
在这项研究中，通过溶胶-凝胶法、微波辐射技术和溶胶固定化法合成了 Ag-WO/膨润土纳米复合材料，以研究其对腐殖酸光催化降解活性的影响。采用 X 射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、场发射扫描电子显微镜（FE-SEM）与能谱仪（EDX）、紫外-可见漫反射光谱（UV-Vis DRS）、Brunauer-Emmett-Teller（BET）法和透射电子显微镜（TEM）对合成材料的光学和结构性质进行了表征。XRD 和 EDX 图谱中 Ag 和 WO 峰的存在证实了复合材料中 Ag-WO 纳米粒子的合成。粉末 X 射线衍射图谱显示所制备的 WO 样品具有单斜结构。WO 基纳米复合材料的组成部分（Ag 和膨润土）提高了其光催化活性，降低了 WO 的光学带隙能。与原始 WO3 样品相比，二元（Ag-WO）纳米复合材料在可见光照射下对腐殖酸（HA）的降解率从 58%（原始 WO3）提高到 82%（Ag-WO），表现出更好的光催化活性。值得注意的是，在自然条件（pH=7.0 和 25°C）下，三元（Ag-WO/bent）纳米复合材料对 HA 降解表现出优异的光催化效率（91.0%）。Ag-WO/bent 中 HA 的降解符合准一级动力学。综上所述，将 Ag、WO、膨润土和可见光辐射结合起来，有效地激活 HA，可以为废水处理提供一种成功而有前途的技术。
