The laccase-like reactivity of manganese oxide nanomaterials for pollutant conversion: rate analysis and cyclic voltammetry

• Published in: Scientific reports 2017-08, Vol.7 (1), p.7756-10, Article 7756
• Main Authors: Wang, Xinghao, Liu, Jiaoqin, Qu, Ruijuan, Wang, Zunyao, Huang, Qingguo
• Format: Article
• Language: English
• Subjects: 17β-Estradiol; 704/172/169/896; 704/4111; Catalysis; Catalysts; Humanities and Social Sciences; Laccase; Manganese; Manganese oxides; multidisciplinary; Nanomaterials; Nanotechnology; Oxidation; Oxides; Pollutants; Science; Science (multidisciplinary); Voltammetry; Wastewater treatment
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-07913-2

Nanostructured manganese oxides, e.g. MnO 2 , have shown laccase-like catalytic activities, and are thus promising for pollutant oxidation in wastewater treatment. We have systematically compared the laccase-like reactivity of manganese oxide nanomaterials of different crystallinity, including α-, β-, γ-, δ-, and ɛ-MnO 2 , and Mn 3 O 4 , with 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS) and 17β-estradiol (E2) as the probing substrates. The reaction rate behaviors were examined with regard to substrate oxidation and oxygen reduction to evaluate the laccase-like catalysis of the materials, among which γ-MnO 2 exhibits the best performance. Cyclic voltammetry (CV) was employed to assess the six MnO x nanomaterials, and the results correlate well with their laccase-like catalytic activities. The findings help understand the mechanisms of and the factors controlling the laccase-like reactivity of different manganese oxides nanomaterials, and provide a basis for future design and application of MnO x -based catalysts.