Sharma Shelja, Ibhadon Alex O, Francesconi M Grazia, Mehta Surinder Kumar, Elumalai Sasikumar, Kansal Sushil Kumar, Umar Ahmad, Baskoutas Sotirios
Chemical Engineering Division, Centre of Innovative and Applied Bioprocessing, Mohali-140306, India.
Department of Chemical Engineering, The University of Hull, Hull HU6 7RX, UK.
Nanomaterials (Basel). 2020 May 8;10(5):910. doi: 10.3390/nano10050910.
Photocatalytic materials and semiconductors of appropriate structural and morphological architectures as well as energy band gaps are materials needed for mitigating current environmental problems, as these materials have the ability to exploit the full spectrum of solar light in several applications. Thus, constructing a Z-scheme heterojunction is an ideal approach to overcoming the limitations of a single component or traditional heterogeneous catalysts for the competent removal of organic chemicals present in wastewater, to mention just one of the areas of application. A Z-scheme catalyst possesses many attributes, including enhanced light-harvesting capacity, strong redox ability and different oxidation and reduction positions. In the present work, a novel ternary Z-scheme photocatalyst, i.e., BiWO/C-dots/TiO has been prepared by a facile chemical wet technique. The prepared solar light-driven Z-scheme composite was characterized by many analytical and spectroscopic practices, including powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), N adsorption-desorption isotherm, Fourier-transform infrared spectroscopy (FT-IR), photoluminescence (PL) and UV-vis diffuse reflectance spectroscopy (DRS). The photocatalytic activity of the BiWO/C-dots/TiO composite was evaluated by studying the degradation of fluoroquinolone drug, levofloxacin under solar light irradiation. Almost complete (99%) decomposition of the levofloxacin drug was observed in 90 min of sunlight irradiation. The effect of catalyst loading, initial substrate concentration and pH of the reaction was also optimized. The photocatalytic activity of the prepared catalyst was also compared with that of bare BiWO, TiO and TiO/C-dots under optimized conditions. Scavenger radical trap studies and terephthalic acid (TPA) fluorescence technique were done to understand the role of the photo-induced active radical ions that witnessed the decomposition of levofloxacin. Based on these studies, the plausible degradation trail of levofloxacin was proposed and was further supported by LC-MS analysis.
具有适当结构、形态结构以及能带隙的光催化材料和半导体是缓解当前环境问题所需的材料，因为这些材料能够在多种应用中利用太阳光的全光谱。因此，构建Z型异质结是克服单一组分或传统多相催化剂的局限性以有效去除废水中有机化学品的理想方法，仅提及其中一个应用领域。Z型催化剂具有许多特性，包括增强的光捕获能力、强大的氧化还原能力以及不同的氧化和还原位点。在本工作中，通过简便的化学湿法技术制备了一种新型三元Z型光催化剂，即BiWO/C点/TiO。所制备的太阳光驱动Z型复合材料通过多种分析和光谱方法进行了表征，包括粉末X射线衍射（XRD）、场发射扫描电子显微镜（FE-SEM）、N吸附-脱附等温线、傅里叶变换红外光谱（FT-IR）、光致发光（PL）和紫外-可见漫反射光谱（DRS）。通过研究氟喹诺酮药物左氧氟沙星在太阳光照射下的降解来评估BiWO/C点/TiO复合材料的光催化活性。在90分钟的阳光照射下，观察到左氧氟沙星药物几乎完全（99%）分解。还优化了催化剂负载量、初始底物浓度和反应pH的影响。在优化条件下，还将所制备催化剂的光催化活性与裸BiWO、TiO和TiO/C点的光催化活性进行了比较。进行了清除剂自由基捕获研究和对苯二甲酸（TPA）荧光技术，以了解见证左氧氟沙星分解的光致活性自由基离子的作用。基于这些研究，提出了左氧氟沙星可能的降解途径，并通过液相色谱-质谱（LC-MS）分析得到了进一步支持。
