Department of Chemistry, School of Natural Sciences, National University of Sciences and Technology, Islamabad, 44000, Pakistan.
Department of Chemistry, School of Natural Sciences, National University of Sciences and Technology, Islamabad, 44000, Pakistan.
Environ Res. 2023 Oct 1;234:116550. doi: 10.1016/j.envres.2023.116550. Epub 2023 Jul 16.
A facile two-step hydrothermal method was successfully used to prepare a photocatalyst BiWO/WS heterojunction for methyl blue (MB) photodegradation. Fabricated photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray analysis (EDX), and X-ray photoelectron spectroscopy (XPS). Band gap measurements were carried out by diffuse reflectance spectroscopy (DRS). Results indicated that the prepared heterostructure photocatalyst has increased visible light absorption. Photocatalytic performance was evaluated under sunlight irradiation for methylene blue (MB) degradation as a model dye. Variations in pH (4-10), amount of catalyst (0.025-0.1 g/L), and initial MB concentrations (5-20 ppm) were carried out, whereas all prepared catalysts were used to conduct the tests with a visible spectrophotometer. Degradation activity improved with the pH increase; the optimum pH was approximately 8. Catalyst concentration is directly related to degradation efficiency and reached 93.56% with 0.075 g of the catalyst. Among tested catalysts, 0.01 BiWO/WS has exhibited the highest activity and a degradation efficiency of 99.0% in 40 min (min) for MB. MB photodegradation follows pseudo-first-order kinetics, and obtained values of k were 0.0482 min, 0.0337 min, 0.0205 min and 0.0087 min for initial concentrations of 5 ppm, 10 ppm, 15 ppm, and 20 ppm, respectively. The catalyst was reused for six cycles with a negligible decrease in the degradation activity. Heterostructure 0.01 BiWO/WS has exhibited a photocurrent density of 16 μA cm, significantly higher than 2.0 and 4.5 μA cm for the pristine WS and BiWO, respectively. The findings from these investigations may serve as a crucial stepping stone towards the remediation of polluted water facilitated by implementing such highly efficient photocatalysts.
一种简便的两步水热法成功地用于制备光催化剂 BiWO/WS 异质结用于亚甲基蓝 (MB) 的光降解。通过 X 射线衍射 (XRD)、扫描电子显微镜 (SEM)、能谱 (EDX) 和 X 射线光电子能谱 (XPS) 对制备的光催化剂进行了表征。通过漫反射光谱 (DRS) 进行了带隙测量。结果表明，所制备的异质结构光催化剂增加了可见光吸收。在阳光照射下评价了光催化性能，以亚甲基蓝 (MB) 降解作为模型染料。研究了 pH 值 (4-10)、催化剂用量 (0.025-0.1 g/L) 和初始 MB 浓度 (5-20 ppm) 的变化，而所有制备的催化剂都用于用可见分光光度计进行测试。降解活性随 pH 值的增加而提高；最佳 pH 值约为 8。催化剂浓度与降解效率直接相关，用 0.075 g 催化剂达到 93.56%。在所测试的催化剂中，0.01 BiWO/WS 表现出最高的活性，在 40 分钟内对 MB 的降解效率为 99.0%。MB 的光降解符合准一级动力学，对于初始浓度为 5 ppm、10 ppm、15 ppm 和 20 ppm 的 MB，获得的 k 值分别为 0.0482 min、0.0337 min、0.0205 min 和 0.0087 min。催化剂重复使用六次，降解活性几乎没有下降。异质结构 0.01 BiWO/WS 表现出 16 μA cm 的光电流密度，明显高于原始 WS 和 BiWO 的 2.0 和 4.5 μA cm。这些研究的结果可以为实施这种高效光催化剂促进受污染水的修复提供重要的基石。
