Hierarchically porous SiO2/C hollow microspheres: a highly efficient adsorbent for Congo Red removal. Issue 35 (30th May 2018)

• Record Type: Journal Article
• Authors: Wang, Jie; Xiao, Longya; Wen, Shuai; Chen, Nuo; Dai, Zhiyin; Deng, Junyang; Nie, Longhui; Min, Jie
• Is Part Of: RSC advances. Volume 8:Issue 35(2018)
• Page Start: 19852
• Page End: 19860
• Publication Date: 2018-05-30
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c8ra02988a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Hierarchically porous SiO2 /C hollow microspheres (HPSCHMs) were synthesized. Its surface area is up to 1154 m 2 g –1 . Hierarchically porous structure facilitates diffusion of adsorbate. Its maximum adsorption amount for Congo Red is up to 2512 mg g –1 . Abstract : Hierarchically porous SiO2 /C hollow microspheres (HPSCHMs) were synthesized by a hydrothermal and NaOH-etching combined route. The adsorption performance of the prepared HPSCHMs was investigated to remove Congo Red (CR) in aqueous solution. The results show that the synthesized composite possesses a hollow microspherical structure with hierarchical pores and a diameter of about 100–200 nm, and its surface area is up to 1154 m 2 g −1 . This material exhibits a remarkable adsorption performance for CR in solution, and its maximum adsorption amount for CR can reach up to 2512 mg g −1 . It shows faster adsorption and much higher adsorption capacity than the commercial AC and γ-Al2 O3 samples under the same conditions. The studies of the kinetics and thermodynamics indicate that the adsorption of CR on the PHSCHM sample obeys the pseudo-second order model well and belongs to physisorption. The adsorption activation energy is about 7.72 kJ mol −1 . In view of the hierarchically meso–macroporous structure, large surface area and pore volume, the HPSCHM material could be a promising adsorbent for removal of pollutants, and it could also be used as a catalyst support.