A facile one-pot synthesis of three-dimensional microflower birnessite (δ-MnO2) and its efficient oxidative degradation of rhodamine B. Issue 28 (1st March 2016)

• Record Type: Journal Article
• Authors: Qin, Minggao; Zhao, Haoliang; Yang, Weijun; Zhou, Yuanrong; Li, Feng
• Is Part Of: RSC advances. Volume 6:Issue 28(2016)
• Page Start: 23905
• Page End: 23912
• Publication Date: 2016-03-01
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c5ra24848e
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : A facile synthesis of high purity microflower birnessite and its efficient oxidative degradation of RhB. Abstract : High purity birnessite (δ-MnO2 ) was obtained by a facile one-pot method using MnSO4 ·H2 O as a Mn resource, ethylenediamine tetraacetic acid disodium salt (EDTA-Na) as a complexing agent and oxygen in the air as an oxidant under alkaline conditions. The as-prepared birnessite presented three-dimensional microflowers composed of two-dimensional ultrathin nanosheets. Degradation results indicated that the prepared δ-MnO2 possessed excellent abilities for removal of rhodamine B (RhB). Typically, 50 mL of RhB (10 mg L −1 ) could be degraded completely with a 10 mg sample in 5 min without any additives such as hydrogen peroxide, peroxysulphate or any supplementary means such as microwaves or ultrasound. The samples were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), and N2 gas adsorption–desorption and thermogravimetry analysis (TGA) techniques. The mechanism of the degradation process was proposed and it was discussed that a redox reaction between birnessite and RhB occurred in an acidic environment. Clearly, the as-prepared birnessite provides great potential for the rapid degradation of dyes and organic pollutants. As it has easily available starting materials, a simple method for synthesis and undemanding degradation conditions, the as-prepared birnessite has high practical value in treating environmental pollutants.