화학공학소재연구정보센터
Applied Catalysis B: Environmental, Vol.227, 433-445, 2018
Controlled Synthesis of highly proficient and durable hollow hierarchical heterostructured (Ag-AgBr/HHST): A UV and Visible light active photocatalyst in degradation of organic pollutants
Progression in nano technology enormously influence on the synthesis of highly proficient photo materials and investigate their applications in diverse fields. A novel mesoporous heterostructure Ag-AgBr/HHST (hollow hierarchical silica-titania supported silver-silverbromide), synthesized by a facile one-pot micro emulsification method at controlled calcination temperature and investigated its photocatalytic performance for the degradation of methyl orange and aniline as ultra violet and visible light responsive material. Mesoporous Ag-AgBr/HHST was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), UV-vis. diffuse reflectance spectroscopy (UV-vis. DRS), Nitrogen adsorption-desorption analysis, photoelectron spectroscopic measurements (XPS) and photoluminescence spectral analysis (PL). The XRD, HRTEM and optical spectroscopic analysis justified the incredible effect of calcination temperature on the structure and morphology of nano composite. The results indicates, the photo catalyst synthesized at optimum calcinations temperature (550 degrees C) consist of small-hollow-spheres@big-hollow-spheres, leading the Ag and AgBr nano particles with an average particle size of 2-8 nm are homogeneously distributed on the surface of the hollow hierarchical silica-titania matrix, some particles are deeply embedded in HHST. Due to exceptional morphology, high surface area, small particles size and porous structure, the Ag-AgBr/HHST revealed elevated photocatalytic performance to degraded the 200 mL (200 ppm) of each methyl orange and aniline under simulated ultra violet as well as visible light irradiations in very short time intervals. Hollow hierarchical silica-titania offer high-quality conducting channel to pick up mass loading and enhance charge transfer. Whereas, strong connection of Ag and AgBr with silica-titania, feature highly active sites that causes synergetic effect capable for commendable photocatalytic performance compared with individual HHST, Ag-AgBr and (Degussa P25). While the photocatalyst obtained at 650 degrees C have some extant of phase conversion starting anatase to rutile phase of titania, and consist of big sized aggregated nano particles. The recycling runs experiments and reusability of the photocatalyst illustrate the venerable stability of the material that strengthens the synthesis of novel hollow hierarchical mesoporous compounds in this domains.