The Controlled Synthesis of Birnessite Nanoflowers via H2O2 Reducing KMnO4 For Efficient Adsorption and Photooxidation Activity

Yang Li; Guanjie Jiang; Nanqi Ouyang; Zhangjie Qin; Shuai Lan; Qin Zhang

doi:10.3389/fchem.2021.699513

The Controlled Synthesis of Birnessite Nanoflowers via H₂O₂ Reducing KMnO₄ For Efficient Adsorption and Photooxidation Activity

Front Chem. 2021 May 26:9:699513. doi: 10.3389/fchem.2021.699513. eCollection 2021.

Authors

Yang Li¹, Guanjie Jiang¹, Nanqi Ouyang¹, Zhangjie Qin¹, Shuai Lan¹, Qin Zhang¹

Affiliation

¹ Key Laboratory of Poyang Lake Watershed Agricultural Resources and Ecology of Jiangxi Province, College of Land Resources and Environment, Jiangxi Agricultural University, Nanchang, China.

Abstract

Birnessite nanoflowers composed of layers have been proven to be the strongest adsorbent and oxidant in the surface environment. However, the current synthesis methods of birnessite nanoflowers are suffering from long reaction time and high reaction temperature. Based on these, this paper explores a new method for the rapid and controlled synthesis of layered manganese oxides. The method relies on the molar ratios of KMnO₄ and H₂O₂ redox reacting species to drive the production of birnessite nanoflowers under acidic conditions. The molar ratios of KMnO₄ and H₂O₂ are the key to the crystal structure of the as-prepared. It was found that when the molar ratios of KMnO₄ and H₂O₂ is from 1:1.25 to 1:1.90, the sample is birnessite nanoflowers, and when the ratio is increased to 1:2.0, the sample is a mixture of birnessite nanoflowers and feitknechtite nanoplates. Among the as-prepared samples, BF-1.85 (molar ratios of KMnO₄ and H₂O₂ is 1:1.85) shows the highest capacity for Pb²⁺ adsorption (2,955 mmol/kg) and greatest degradation efficiency of phenol and TOC. The method proposed herein is economical and controllable, and it yields products with high efficiency for the elimination of inorganic and organic pollutants.

Keywords: Pb 2+; adsorption; birnessite; phenol; photooxidation.