Facile preparation of mesoporous nickel oxide microspheres and their adsorption property for methyl orange from aqueous solution

• Published in: Materials science in semiconductor processing 2014-10, Vol.26, p.716-725
• Main Authors: Jia, Zhigang, Liu, Jianhong, Wang, Qiuze, Ye, Mingfu, Zhu, Rongsun
• Format: Article
• Language: English
• Subjects: Adsorption; Applied sciences; Chemical preparation; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Dyes; Electronics; Exact sciences and technology; Materials science; Mathematical models; Microelectronic fabrication (materials and surfaces technology); Microspheres; Nickel oxide; Oxalates; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Porosity; Porous materials; granular materials; Precipitation; Scanning electron microscopy; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Semiconductors; Solid surfaces and solid-solid interfaces; Specific materials; Surface chemistry; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Template
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2014.06.026

Mesoporous NiO microspheres with the average diameters of 1.5μm, 2μm, 5μm and 10μm were successfully prepared by the direct thermal transformation of nickel oxalate microspheres as the sacrificial oxalate template, which was facilely synthesized by simple precipitation reaction with controllable size in the control of polyvinyl alcohol. The obtained samples were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM) and nitrogen adsorption–desorption measurement. Specific surface area of the mesoporous NiO microspheres with the average diameters of 10μm was calculated as 110.2m2g−1 by BET method. The mesoporous NiO microspheres as adsorbents exhibited rapid adsorption rate for methyl orange and high adsorption capacity of 113.64mgg−1 for methyl orange. Batch kinetic experiments showed that pseudo-second-order kinetic equation can better describe the adsorption kinetics, and the experimental data of equilibrium adsorption fitted very well to Langmuir model. The thermodynamic parameters of ΔG°, ΔH° and ΔS° showed that adsorption of methyl orange on mesoporous NiO microspheres was an exothermic and spontaneous in nature.