Synthesis of hierarchical porous zinc oxide (ZnO) microspheres with highly efficient adsorption of Congo red

• Published in: Journal of colloid and interface science Vol. 490; pp. 242 - 251
• Main Authors: Lei, Chunsheng, Pi, Meng, Jiang, Chuanjia, Cheng, Bei, Yu, Jiaguo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15.03.2017
• Subjects: adsorbents; adsorption; Adsorption isotherm; Anionic dye; aqueous solutions; Congo red; dyes; Fourier transform infrared spectroscopy; Hierarchical porous structure; hot water treatment; microparticles; nanosheets; nitrogen; scanning electron microscopy; sorption isotherms; transmission electron microscopy; wastewater; X-ray diffraction; Zinc oxide; Zinc oxide; Congo red; Hierarchical porous structure; Anionic dye; Adsorption isotherm
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2016.11.049

[Display omitted] Hierarchical porous zinc oxide (ZnO) was successfully synthesized via a facile hydrothermal method followed by calcination, and characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, nitrogen adsorption–desorption, and Fourier transform infrared spectroscopy analyses. The as-prepared porous ZnO exhibits microsphere morphologies with diameters of 6–8μm, which are assembled from two-dimensional nanosheets. The as-prepared hierarchical porous ZnO microspheres possessed high specific surface areas (57m2/g), and were evaluated for adsorption of Congo red (CR) in aqueous solution. The adsorption kinetics data were described by the pseudo-second-order kinetics and intraparticle diffusion models, while the equilibrium adsorption data were well fitted to the Langmuir model, with a maximum adsorption amount of 334mg/g. The as-prepared hierarchical porous ZnO exhibited higher CR adsorption capacity than commercial ZnO and various other materials, and thus could be an effective adsorbent for removal of anionic organic dyes from wastewater.