Sanad Mohamed F, Shalan Ahmed Esmail, Ahmed M A, Messih M F Abdel
Chemistry Department, Faculty of Science, Ain Shams University Egypt
Department of Chemistry and Department of Environmental Sciences and Engineering, University of Texas at El Paso 500 West University Avenue El Paso Texas 79968 USA.
RSC Adv. 2021 Jun 24;11(36):22352-22364. doi: 10.1039/d1ra02284a. eCollection 2021 Jun 21.
A ZnS/SiO photocatalyst was synthesized using a low-cost sol-gel wet chemical procedure. The as-synthesized ZnS/SiO nanocomposites with different molar ratios exhibited superior performance in the photodegradation of two organic dyes under UV irradiation, with complete degradation of both dyes after 2 hours of exposure to UV irradiation. The photocatalyst structure, microstructure, and surface area were studied using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FESEM), and nitrogen adsorption ( ) studies. The results demonstrate that the ZnS/SiO photocatalyst with 15% ZnS content has a bandgap energy similar to that of ZnS alone with a higher surface area of approximately 150 m g, which effectively increases the number of active sites and improves the photocatalytic activity of the prepared material. The measured bandgap energies were compared with the theoretical values obtained using the density functional theory (DFT) method, and the values were found to be very similar, with a low error percentage. In the case of a high ZnS content (greater than 15%), active site blocking occurred, and the removal rate dropped below 50%. The obtained results indicate that the photocatalytic data are in good agreement with the experimental characterization results for the prepared materials, including the BET and XRD results, confirming a close association between the photocatalytic activity and the surface area of the fabricated photocatalyst.
采用低成本的溶胶 - 凝胶湿化学法合成了一种ZnS/SiO光催化剂。所合成的不同摩尔比的ZnS/SiO纳米复合材料在紫外光照射下对两种有机染料的光降解表现出优异的性能,在紫外光照射2小时后两种染料均完全降解。使用X射线衍射(XRD)、高分辨率透射电子显微镜(HRTEM)、场发射扫描电子显微镜(FESEM)和氮吸附研究了光催化剂的结构、微观结构和表面积。结果表明,ZnS含量为15%的ZnS/SiO光催化剂的带隙能量与单独的ZnS相似,且具有约150 m²/g的较高表面积,这有效地增加了活性位点的数量并提高了所制备材料的光催化活性。将测量的带隙能量与使用密度泛函理论(DFT)方法获得的理论值进行比较,发现两者非常相似,误差百分比很低。在高ZnS含量(大于15%)的情况下,发生了活性位点阻塞,去除率降至50%以下。所得结果表明,光催化数据与所制备材料的实验表征结果(包括BET和XRD结果)吻合良好,证实了光催化活性与所制备光催化剂的表面积之间存在密切关联。