Ghouri Zafar Khan, Elsaid Khaled, Abdala Ahmed, Al-Meer Saeed, Barakat Nasser A M
Chemical Engineering Program, Texas A&M University at Qatar, P.O. 23874, Doha, Qatar.
Central Laboratories Unit, Qatar University, P. O. Box: 2713, Doha, Qatar.
Sci Rep. 2018 Oct 2;8(1):14656. doi: 10.1038/s41598-018-33108-4.
In this study, hybrid graphene-Pt/TiO nanostructure were synthesized by single-step, inexpensive and surfactant/organic solvent free route; hydrothermal technique. The physicochemical properties of hybrid graphene-Pt/TiO nanostructure were carefully analyzed by multiple techniques, including X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM). The synthesized hybrid nanostructures were utilized as photocatalyst for the degradation of methylene blue (MB) dye under natural environment at average ambient temperature and mean daily global solar radiation, of about 22-25 °C and 374.9 mWh/cm, respectively. The activity performance indicated considerable degradation of methylene blue (MB) dye and was in the following order Gr (13%), TiO (60%) and hybrid graphene-Pt/TiO nanostructure (90%) over 21 min under the natural light illumination. The physiochemical characterization suggests that, the tightly attached metalized TiO nanoparticles (Pt-TiO) on the high surface area graphene sheets improved utilization of visible light and increased separation and transfer of photo-excited electron (ē) hole (h) pairs. Notably, the hybrid graphene-Pt/TiO nanostructure exhibited an excellent cyclic stability for methylene blue (MB) dye removal. Finally, the kinetic behavior indicated that the photocatalytic degradation reaction of the dye obeyed the pseudo-first order (Langmuir-Hinshelwood) kinetics model.
在本研究中,通过单步、廉价且无表面活性剂/有机溶剂的水热技术路线合成了石墨烯-Pt/TiO杂化纳米结构。采用多种技术对石墨烯-Pt/TiO杂化纳米结构的物理化学性质进行了仔细分析,包括X射线衍射仪(XRD)、X射线光电子能谱(XPS)、场发射扫描电子显微镜(FESEM)和透射电子显微镜(TEM)。所合成的杂化纳米结构被用作光催化剂,在平均环境温度约为22-25 °C、平均日全球太阳辐射约为374.9 mWh/cm²的自然环境下用于降解亚甲基蓝(MB)染料。活性性能表明亚甲基蓝(MB)染料有显著降解,在自然光照射下21分钟内,降解顺序为Gr(13%)、TiO(60%)和石墨烯-Pt/TiO杂化纳米结构(90%)。物理化学表征表明,高比表面积石墨烯片上紧密附着的金属化TiO纳米颗粒(Pt-TiO)提高了可见光的利用率,并增加了光激发电子(ē)-空穴(h)对的分离和转移。值得注意的是,石墨烯-Pt/TiO杂化纳米结构在去除亚甲基蓝(MB)染料方面表现出优异的循环稳定性。最后,动力学行为表明染料的光催化降解反应符合准一级(Langmuir-Hinshelwood)动力学模型。